ORCID Profile
0000-0002-5886-4421
Current Organisation
Queensland University of Technology
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Environmental Science and Management | Conservation and Biodiversity | Marine and Estuarine Ecology (incl. Marine Ichthyology) | Population Ecology | Environmental Management | Wildlife and Habitat Management | Environmental Management And Rehabilitation | Wildlife And Habitat Management | Conservation | Climate Change Processes | Global Change Biology | Ecosystem Function | Other Biological Sciences | Invasive Species Ecology | Landscape Ecology | Natural Resource Management
ANZSRC Socio-Economic Objective (SEO)
Wild Caught Fin Fish (excl. Tuna) | Marine Flora, Fauna and Biodiversity | Control of pests and exotic species | Effects of Climate Change and Variability on Antarctic and Sub-Antarctic Environments (excl. Social Impacts) | Coastal and Marine Management Policy | Climate Variability (excl. Social Impacts) | Integrated (ecosystem) assessment and management | Ecosystem Assessment and Management of Antarctic and Sub-Antarctic Environments | Ecosystem Assessment and Management at Regional or Larger Scales | Control of pests and exotic species | Fisheries - Recreational | Ecosystem Assessment and Management of Sparseland, Permanent Grassland and Arid Zone Environments | Control of Pests, Diseases and Exotic Species not elsewhere classified | Environmental Policy, Legislation and Standards not elsewhere classified | Control of Pests, Diseases and Exotic Species in Sparseland, Permanent Grassland and Arid Zone Environments |
Related Links
Publications
A novel approach to assessing the ecosystem‐wide impacts of reintroductions
Publisher: Wiley
Date: 20-11-2018
DOI: 10.1002/EAP.1811
Abstract: Reintroducing a species to an ecosystem can have significant impacts on the recipient ecological community. Although reintroductions can have striking and positive outcomes, they also carry risks many well-intentioned conservation actions have had surprising and unsatisfactory outcomes. A range of network-based mathematical methods has been developed to make quantitative predictions of how communities will respond to management interventions. These methods are based on the limited knowledge of which species interact with each other and in what way. However, expert knowledge isn't perfect and can only take models so far. Fortunately, other types of data, such as abundance time series, is often available, but, to date, no quantitative method exists to integrate these various data types into these models, allowing more precise ecosystem-wide predictions. In this paper, we develop mathematical methods that combine time-series data of multiple species with knowledge of species interactions and we apply it to proposed reintroductions at Booderee National Park in Australia. There have been large fluctuations in species abundances at Booderee National Park in recent history, following intense feral fox (Vulpes vulpes) control, including the local extinction of the greater glider (Petauroides volans). These fluctuations can provide information about the system isn't readily obtained from a stable system, and we use them to inform models that we then use to predict potential outcomes of eastern quoll (Dasyurus viverrinus) and long-nosed potoroo (Potorous tridactylus) reintroductions. One of the key species of conservation concern in the park is the Eastern Bristlebird (Dasyornis brachypterus), and we find that long-nosed potoroo introduction would have very little impact on the Eastern Bristlebird population, while the eastern quoll introduction increased the likelihood of Eastern Bristlebird decline, although that depends on the strength and form of any possible interaction.
A modified May–Holling–Tanner predator-prey model with multiple Allee effects on the prey and an alternative food source for the predator
Publisher: American Institute of Mathematical Sciences (AIMS)
Date: 2021
Choosing optimal trigger points for ex situ, in toto conservation of single population threatened species
Publisher: Public Library of Science (PLoS)
Date: 07-04-2022
DOI: 10.1371/JOURNAL.PONE.0266244
Abstract: Many endangered species exist in only a single population, and almost all species that go extinct will do so from their last remaining population. Understanding how to best conserve these single population threatened species (SPTS) is therefore a distinct and important task for threatened species conservation science. As a last resort, managers of SPTS may consider taking the entire population into captivity– ex situ , in toto conservation. In the past, this choice has been taken to the great benefit of the SPTS, but it has also lead to catastrophe. Here, we develop a decision-support tool for planning when to trigger this difficult action. Our method considers the uncertain and ongoing decline of the SPTS, the possibility that drastic ex situ action will fail, and the opportunities offered by delaying the decision. Specifically, these benefits are additional time for ongoing in situ actions to succeed, and opportunities for the managers to learn about the system. To illustrate its utility, we apply the decision tool to four retrospective case-studies of declining SPTS. As well as offering support to this particular decision, our tool illustrates why trigger points for difficult conservation decisions should be formulated in advance, but must also be adaptive. A trigger-point for the ex situ , in toto conservation of a SPTS, for ex le, will not take the form of a simple threshold abundance.
Modeling herbivore functional responses causing boom‐bust dynamics following predator removal
Publisher: Wiley
Date: 07-02-2021
DOI: 10.1002/ECE3.7185
Long-term shifts in the colony size structure of coral populations along the Great Barrier Reef
Publisher: The Royal Society
Date: 14-10-2020
Abstract: The age or size structure of a population has a marked influence on its demography and reproductive capacity. While declines in coral cover are well documented, concomitant shifts in the size-frequency distribution of coral colonies are rarely measured at large spatial scales. Here, we document major shifts in the colony size structure of coral populations along the 2300 km length of the Great Barrier Reef relative to historical baselines (1995/1996). Coral colony abundances on reef crests and slopes have declined sharply across all colony size classes and in all coral taxa compared to historical baselines. Declines were particularly pronounced in the northern and central regions of the Great Barrier Reef, following mass coral bleaching in 2016 and 2017. The relative abundances of large colonies remained relatively stable, but this apparent stability masks steep declines in absolute abundance. The potential for recovery of older fecund corals is uncertain given the increasing frequency and intensity of disturbance events. The systematic decline in smaller colonies across regions, habitats and taxa, suggests that a decline in recruitment has further eroded the recovery potential and resilience of coral populations.
Using ensemble modeling to predict the impacts of assisted migration on recipient ecosystems
Publisher: Wiley
Date: 02-09-2021
DOI: 10.1111/COBI.13571
Prioritizing eradication actions on islands: it's not all or nothing
Publisher: Wiley
Date: 14-01-2016
Minimizing species extinctions through strategic planning for conservation fencing
Publisher: Wiley
Date: 28-07-2017
DOI: 10.1111/COBI.12922
Abstract: Conservation fences are an increasingly common management action, particularly for species threatened by invasive predators. However, unlike many conservation actions, fence networks are expanding in an unsystematic manner, generally as a reaction to local funding opportunities or threats. We conducted a gap analysis of Australia's large predator-exclusion fence network by examining translocation of Australian mammals relative to their extinction risk. To address gaps identified in species representation, we devised a systematic prioritization method for expanding the conservation fence network that explicitly incorporated population viability analysis and minimized expected species' extinctions. The approach was applied to New South Wales, Australia, where the state government intends to expand the existing conservation fence network. Existing protection of species in fenced areas was highly uneven 67% of predator-sensitive species were unrepresented in the fence network. Our systematic prioritization yielded substantial efficiencies in that it reduced expected number of species extinctions up to 17 times more effectively than ad hoc approaches. The outcome illustrates the importance of governance in coordinating management action when multiple projects have similar objectives and rely on systematic methods rather than expanding networks opportunistically.
Optimal Conservation Outcomes Require Both Restoration and Protection
Publisher: Public Library of Science (PLoS)
Date: 27-01-2015
Reconstructing lost ecosystems: A risk analysis framework for planning multispecies reintroductions under severe uncertainty
Publisher: Wiley
Date: 13-08-2021
Abstract: Reintroduction projects, which are an important tool in threatened species conservation, are becoming more complex, often involving the translocation of multiple species. Ecological theory predicts that the sequence and timing of reintroductions will play an important role in their success or failure. Following the removal of sheep, goats and feral cats, the Western Australian government is sequentially reintroducing 13 native fauna species to restore the globally important natural and cultural values of Dirk Hartog Island (DHI). We use ensembles of ecosystem models to compare 23 alternative reintroduction strategies on DHI, in Western Australia. The reintroduction strategies differ in the order, timing and location of releases on the island. Expert elicitation informed the model structure, allowing for use of different presumed species interaction networks which explicitly incorporated uncertainty in ecosystem dynamics. Our model ensembles predict that almost all of the species (~12.5 of 13, on average) will successfully establish in the ecosystem studied, regardless of which reintroduction strategy is undertaken. The project can therefore proceed with greater confidence and flexibility regarding the reintroduction strategy. However, the identity of the at‐risk species varies between strategies, and depends on the structure of the species interaction network, which is quite uncertain. The model ensembles also offer insights into why some species fail to establish on DHI, predicting that most unsuccessful reintroductions will be the result of competitive interactions with extant species. Synthesis and applications . Our model ensembles allow for the comparison of outcomes between reintroduction strategies and between different species interaction networks. This framework allows for inclusion of high uncertainty in dynamics. Finally, an ensemble modelling approach also creates a foundation for formal adaptive management as reintroduction projects proceed.
Marine Dispersal Scales Are Congruent over Evolutionary and Ecological Time
Publisher: Elsevier BV
Date: 2017
DOI: 10.1016/J.CUB.2016.10.053
Abstract: The degree to which offspring remain near their parents or disperse widely is critical for understanding population dynamics, evolution, and biogeography, and for designing conservation actions. In the ocean, most estimates suggesting short-distance dispersal are based on direct ecological observations of dispersing in iduals, while indirect evolutionary estimates often suggest substantially greater homogeneity among populations. Reconciling these two approaches and their seemingly competing perspectives on dispersal has been a major challenge. Here we show for the first time that evolutionary and ecological measures of larval dispersal can closely agree by using both to estimate the distribution of dispersal distances. In orange clownfish (Amphiprion percula) populations in Kimbe Bay, Papua New Guinea, we found that evolutionary dispersal kernels were 17 km (95% confidence interval: 12-24 km) wide, while an exhaustive set of direct larval dispersal observations suggested kernel widths of 27 km (19-36 km) or 19 km (15-27 km) across two years. The similarity between these two approaches suggests that ecological and evolutionary dispersal kernels can be equivalent, and that the apparent disagreement between direct and indirect measurements can be overcome. Our results suggest that carefully applied evolutionary methods, which are often less expensive, can be broadly relevant for understanding ecological dispersal across the tree of life.
Optimal management of a stochastically varying population when policy adjustment is costly
Publisher: Wiley
Date: 04-2016
DOI: 10.1890/15-0236
Abstract: Ecological systems are dynamic and policies to manage them need to respond to that variation. However, policy adjustments will sometimes be costly, which means that fine-tuning a policy to track variability in the environment very tightly will only sometimes be worthwhile. We use a classic fisheries management problem, how to manage a stochastically varying population using annually varying quotas in order to maximize profit, to examine how costs of policy adjustment change optimal management recommendations. Costs of policy adjustment (changes in fishing quotas through time) could take different forms. For ex le, these costs may respond to the size of the change being implemented, or there could be a fixed cost any time a quota change is made. We show how different forms of policy costs have contrasting implications for optimal policies. Though it is frequently assumed that costs to adjusting policies will d en variation in the policy, we show that certain cost structures can actually increase variation through time. We further show that failing to account for adjustment costs has a consistently worse economic impact than would assuming these costs are present when they are not.
Revealing beliefs: using ensemble ecosystem modelling to extrapolate expert beliefs to novel ecological scenarios
Publisher: Wiley
Date: 19-12-2017
Size and spacing rules can balance conservation and fishery management objectives for marine protected areas
Publisher: Wiley
Date: 28-11-2017
Incorporating the effects of socioeconomic uncertainty into priority setting for conservation investment
Publisher: Wiley
Date: 12-2007
DOI: 10.1111/J.1523-1739.2007.00832.X
Abstract: Uncertainty in the implementation and outcomes of conservation actions that is not accounted for leaves conservation plans vulnerable to potential changes in future conditions. We used a decision-theoretic approach to investigate the effects of two types of investment uncertainty on the optimal allocation of global conservation resources for land acquisition in the Mediterranean Basin. We considered uncertainty about (1) whether investment will continue and (2) whether the acquired bio ersity assets are secure, which we termed transaction uncertainty and performance uncertainty, respectively. We also developed and tested the robustness of different rules of thumb for guiding the allocation of conservation resources when these sources of uncertainty exist. In the presence of uncertainty in future investment ability (transaction uncertainty), the optimal strategy was opportunistic, meaning the investment priority should be to act where uncertainty is highest while investment remains possible. When there was a probability that investments would fail (performance uncertainty), the optimal solution became a complex trade-off between the immediate bio ersity benefits of acting in a region and the perceived longevity of the investment. In general, regions were prioritized for investment when they had the greatest performance certainty, even if an alternative region was highly threatened or had higher bio ersity value. The improved performance of rules of thumb when accounting for uncertainty highlights the importance of explicitly incorporating sources of investment uncertainty and evaluating potential conservation investments in the context of their likely long-term success.
On the extinction of the single‐authored paper: The causes and consequences of increasingly collaborative applied ecological research
Publisher: Wiley
Date: 11-12-2017
Oak habitat recovery on California's largest islands: Scenarios for the role of corvid seed dispersal
Publisher: Wiley
Date: 05-12-2017
Simultaneous invasive alien predator eradication delivers the best outcomes for protected island species
Publisher: Springer Science and Business Media LLC
Date: 25-11-2019
Safeguarding Biodiversity and Ecosystem Services in the Little Karoo, South Africa
Publisher: Wiley
Date: 15-07-2010
DOI: 10.1111/J.1523-1739.2009.01442.X
Abstract: Global declines in bio ersity and the widespread degradation of ecosystem services have led to urgent calls to safeguard both. Responses to this urgency include calls to integrate the needs of ecosystem services and bio ersity into the design of conservation interventions. The benefits of such integration are purported to include improvements in the justification and resources available for these interventions. Nevertheless, additional costs and potential trade-offs remain poorly understood in the design of interventions that seek to conserve bio ersity and ecosystem services. We sought to investigate the synergies and trade-offs in safeguarding ecosystem services and bio ersity in South Africa's Little Karoo. We used data on three ecosystem services--carbon storage, water recharge, and fodder provision--and data on bio ersity to examine several conservation planning scenarios. First, we investigated the amount of each ecosystem service captured incidentally by a conservation plan to meet targets for bio ersity only while minimizing opportunity costs. We then examined the costs of adding targets for ecosystem services into this conservation plan. Finally, we explored trade-offs between bio ersity and ecosystem service targets at a fixed cost. At least 30% of each ecosystem service was captured incidentally when all of bio ersity targets were met. By including data on ecosystem services, we increased the amount of services captured by at least 20% for all three services without additional costs. When bio ersity targets were reduced by 8%, an extra 40% of fodder provision and water recharge were obtained and 58% of carbon could be captured for the same cost. The opportunity cost (in terms of forgone production) of safeguarding 100% of the bio ersity targets was about US$500 million. Our results showed that with a small decrease in bio ersity target achievement, substantial gains for the conservation of ecosystem services can be achieved within our bio ersity priority areas for no extra cost.
Introduced species that overcome life history tradeoffs can cause native extinctions
Publisher: Springer Science and Business Media LLC
Date: 30-05-2018
DOI: 10.1038/S41467-018-04491-3
Abstract: Introduced species threaten native bio ersity, but whether exotic species can competitively displace native species remains contested. Building on theory that predicts multi-species coexistence based on a competition-colonisation tradeoff, we derive a mechanistic basis by which human-mediated species invasions could cause extinctions through competitive displacement. In contrast to past invasions, humans principally introduce modern invaders, repeatedly and in large quantities, and in ways that can facilitate release from enemies and competitors. Associated increases in exotic species’ propagule rain, survival and competitive ability could enable some introduced species to overcome the tradeoffs that constrain all other species. Using evidence from metacommunity models, we show how species introductions could disrupt species coexistence, generating extinction debts, especially when combined with other forms of anthropogenic environmental change. Even though competing species have typically coexisted following past biogeographic migrations, the multiplicity and interactive impacts of today’s threats could change some exotic species into agents of extinction.
The Cost of Conservation
Publisher: American Association for the Advancement of Science (AAAS)
Date: 18-07-2008
Costs of dispersal alter optimal offspring size in patchy habitats: combining theory and data for a marine invertebrate
Publisher: Wiley
Date: 05-03-2013
Synthesis and review: Delivering on conservation promises: The challenges of managing and measuring conservation outcomes
Publisher: IOP Publishing
Date: 08-2014
Ecological incumbency impedes stochastic community assembly in Holocene foraminifera from the Huon Peninsula, Papua New Guinea
Publisher: Cambridge University Press (CUP)
Date: 2011
DOI: 10.1666/09087.1
Abstract: Persistence in the structure of ecological communities can be predicted both by deterministic and by stochastic theory. Evaluating ecological patterns against the neutral theory of bio ersity provides an appropriate methodology for differentiating between these alternatives. We traced the history of benthic foraminiferal communities from the Huon Peninsula, Papua New Guinea. From the well-preserved uplifted reef terrace at Bonah River we reconstructed the benthic foraminiferal communities during a 2200-year period (9000–6800 yr B.P.) of reef building during the Holocene transgressive sea-level rise. We found that the similarity of foraminiferal communities was consistently above 60%, even when comparing communities on either side of a massive volcanic eruption that smothered the existing reef system with ash. Similarly, species ersity and rank dominance were unchanged through time. However, similarity dropped dramatically in the final stages of reef growth, when accommodation space was reduced as sea-level rise slowed. We compared the community inertia index (CII) computed from the observed species abundances with that predicted from neutral theory. Despite the differences in foraminiferal community composition in the younger part of the reef sequence, we found an overall greater degree of community inertia with less variance in observed communities than was predicted from neutral theory, regardless of foraminiferal community size or species migration rate. Thus, persistent species assemblages could not be ascribed to neutral predictions. Ecological incumbency of established foraminiferal species likely prevented stochastic increases in both migrant and rare taxa at the Bonah River site. Regardless of the structuring mechanisms, our reconstruction of Holocene foraminiferal assemblages provides historical context for the management and potential restoration of degraded species assemblages.
Using complex network metrics to predict the persistence of metapopulations with asymmetric connectivity patterns
Publisher: Elsevier BV
Date: 06-2008
Dispersal connectivity and reserve selection for marine conservation
Publisher: Elsevier BV
Date: 04-2011
Risk-Benefit and Cost-Effectiveness of Universal Iron Interventions for Public Health Control of Anemia in Young Children in 78 Countries: A Microsimulation Study
Publisher: American Society of Hematology
Date: 29-11-2018
DOI: 10.1182/BLOOD-2018-99-117611
Abstract: Almost 300 million children worldwide are anemic. Universal distribution of iron interventions (iron supplements or iron-containing multiple micronutrient powders, MNPs) to young children (e.g. years of age) is a key World Health Organization recommendation to prevent anemia in low-income countries. However, concerns of iron-induced infection risk and limited effectiveness for anemia and broader child health outcomes have raised questions about whether iron interventions produce a net health benefit and are cost-effective. This has constrained implementation. Net effects likely differ in each country according to the epidemiology of anemia and infection, and local health care costs. Quality of implementation likely also affects net benefit. This means analyses must be country-specific. To help guide policymakers, we estimated country-specific net benefit-risk and cost-effectiveness of universal intervention with MNPs or iron supplements to young children. We developed a bespoke microsimulation model to estimate country-specific net Disability Adjusted Life Years (DALYs) attributable to anemia and infection in children from age 0-18 months who received MNPs, iron supplements or control from age 6-12 months. The model utilised publically available data on anemia, malaria, diarrhoea and respiratory infection epidemiology, and modified their risks according to effect sizes from the pivotal systematic reviews of randomised trials used to inform current guidelines. We next estimated corresponding cost/ DALY averted. We modeled all 78 countries (46 in Africa, 20 in Asia and 12 in Latin America) where WHO reported that anemia prevalence exceeded 40% in 2011, or where pilot iron intervention programmes have been reported to be in place. We found that MNPs and iron supplements produced a net benefit to health in all countries, though the magnitude was heterogeneous.DALYs averted/ 10,000 children in Africa ranged from 20.2 (Egypt) to 81.8 (Burkina Faso), median 49.8 in Asia/Pacific/the Middle East from 22.7 (China) to 110.1 (Yemen), median 33.4, and in Latin America from 14.1 (Ecuador) to 68.5 (Bolivia), median 26.5.The median benefit from iron supplements in Africa was 76.4 DALYs averted/10,000 children and ranged from 39.7 in Zimbabwe to 111.6 in Burkina Faso in Asia/Pacific/Middle East the median benefit was 71.7, ranging from 36.9 in the Phillipines to 133.3 in Pakistan and 133.0 in Yemen and in Latin America the median benefit was 59.1, ranging from 93.5 in Bolivia to 39.5 in Guatemala. The magnitude of net benefit from MNPs and iron supplements on DALYs was strongly positively associated with the prevalence of moderate anemia (e.g. for MNPs: r=0.82, P=2.3x10-20). In Africa, MNPs cost between $961-$4341/DALY averted in Asia/Middle-East/Pacific between $844-$3975/DALY averted, and in Latin America between $1306-$6566/DALY averted. The 10 countries where MNPs are most cost-effective were Yemen ($844/DALY averted), Burkina Faso ($961), Mauritania ($1119), The Gambia ($1165), Guinea-Bissau ($1165), Senegal ($1193), Mali ($1197), Guinea ($1267), and Ghana ($1273). Suboptimal coverage markedly reduced both DALYs averted and cost-effectiveness. The severity, not just overall prevalence of anemia, should be considered when planning a programme. Optimisation of programme coverage is essential to maximise cost-effectiveness. Our results augment existing guidelines and identify locations where iron interventions have the greatest benefit and are most cost-effective. Figure Legend Caterpillar plots and regional maps demonstrating DALYs averted/ 10,000 children for A) Multiple Micronutrient Powders, and b) Iron Supplements. No relevant conflicts of interest to declare.
Reserves in Context: Planning for Leakage from Protected Areas
Publisher: Public Library of Science (PLoS)
Date: 08-06-2015
Australian birds could benefit from predator exclusion fencing
Publisher: Wiley
Date: 22-02-2020
DOI: 10.1111/CSP2.168
Cost-effective global conservation spending is robust to taxonomic group
Publisher: Proceedings of the National Academy of Sciences
Date: 29-04-2008
Abstract: Priorities for conservation investment at a global scale that are based on a single taxon have been criticized because geographic richness patterns vary taxonomically. However, these concerns focused only on bio ersity patterns and did not consider the importance of socioeconomic factors, which must also be included if conservation funding is to be allocated efficiently. In this article, we create efficient global funding schedules that use information about conservation costs, predicted habitat loss rates, and the endemicity of seven different taxonomic groups. We discover that these funding allocation schedules are less sensitive to variation in taxon assessed than to variation in cost and threat. Two-thirds of funding is allocated to the same regions regardless of the taxon, compared with only one-fifth if threat and cost are not included in allocation decisions. Hence, if socioeconomic factors are considered, we can be more confident about global-scale decisions guided by single taxonomic groups.
Acting Optimally for Biodiversity in a World Obsessed with REDD
Publisher: Wiley
Date: 12-04-2013
DOI: 10.1111/CONL.12018
Correction to: Ocean zoning within a sparing versus sharing framework (Theoretical Ecology (2018) 10.1007/s12080-017-0364-x)
Publisher: Springer Science and Business Media LLC
Date: 16-04-2018
Spatial control of invasive species in conservation landscapes
Publisher: Springer Science and Business Media LLC
Date: 10-11-2013
Cost and feasibility of a barrier to halt the spread of invasive cane toads in arid Australia: incorporating expert knowledge into model-based decision-making
Publisher: Wiley
Date: 10-08-2017
Larval fish dispersal in a coral-reef seascape
Publisher: Springer Science and Business Media LLC
Date: 08-05-2017
Abstract: Larval dispersal is a critical yet enigmatic process in the persistence and productivity of marine metapopulations. Empirical data on larval dispersal remain scarce, hindering the use of spatial management tools in efforts to sustain ocean bio ersity and fisheries. Here we document dispersal among subpopulations of clownfish (Amphiprion percula) and butterflyfish (Chaetodon vagabundus) from eight sites across a large seascape (10,000 km
Translocation strategies for multiple species depend on interspecific interaction type
Publisher: No publisher found
Date: 2016
DOI: 10.5061/DRYAD.BH215
Using population viability analysis to guide research and conservation actions for Australia's threatened malleefowl Leipoa ocellata
Publisher: Cambridge University Press (CUP)
Date: 10-2011
DOI: 10.1017/S0030605311000688
Abstract: Malleefowl Leipoa ocellata populations across Australia are declining and the range of the species is contracting. Despite a century of research much uncertainty remains about which factors are driving this decline. Consequently, it is also unclear which conservation actions will reduce the species’ extinction risk. In particular, we lack a quantitative understanding of malleefowl population dynamics. Here we use estimates derived from the literature to provide the first parametrization of a population viability analysis (PVA) for malleefowl. This model creates a quantitative framework for synthesizing existing information and comparing potential management strategies, and will help guide research activities by identifying critical aspects of the malleefowl’s life history. We model population dynamics as stochastic events that depend on in idual characteristics, weather conditions and local management actions. Our PVA indicates that an isolated population of 32 adult birds would almost certainly decline to extinction over a 20-year period. Translocating and releasing captive-bred juveniles slows this rate of decline and intensively baiting for foxes can reverse it. Adult mortality rates have the greatest influence on population viability, and land managers should therefore prioritize conservation actions that target adult survivorship over actions that benefit earlier life stages. Quantitative research on the malleefowl should focus on the demographics of the adult life stage, their dispersal and the impacts of fire and grazing. Our analysis highlights the role of PVA models in assessing the cost-effectiveness of alternative management actions, and framing future research priorities for threatened species.
Translocation strategies for multiple species depend on interspecific interaction type
Publisher: Wiley
Date: 06-2016
DOI: 10.1890/15-0409
Abstract: Conservation translocations, anthropogenic movements of species to prevent their extinction, have increased substantially over the last few decades. Although multiple species are frequently moved to the same location, current translocation guidelines consider species in isolation. This practice ignores important interspecific interactions and thereby risks translocation failure. We model three different two-species systems to illustrate the inherent complexity of multispecies translocations and to assess the influence of different interaction types (consumer-resource, mutualism, and competition) on translocation strategies. We focus on how these different interaction types influence the optimal founder population sizes for successful translocations and the order in which the species are moved (simultaneous or sequential). Further, we assess the effect of interaction strength in simultaneous translocations and the time delay between translocations when moving two species sequentially. Our results show that translocation decisions need to reflect the type of interaction. While all translocations of interacting species require a minimum founder population size, which is demarked by an extinction boundary, consumer-resource translocations also have a maximum founder population limit. Above the minimum founder size, increasing the number of translocated in iduals leads to a substantial increase in the extinction boundary of competitors and consumers, but not of mutualists. Competitive and consumer-resource systems benefit from sequential translocations, but the order of translocations does not change the outcomes for mutualistic interaction partners noticeably. Interspecific interactions are important processes that shape population dynamics and should therefore be incorporated into the quantitative planning of multispecies translocations. Our findings apply whenever interacting species are moved, for ex le, in reintroductions, conservation introductions, biological control, or ecosystem restoration.
Adaptive management informs conservation and monitoring of Australia's threatened malleefowl
Publisher: Elsevier BV
Date: 05-2019
THE QUICK AND THE DEAD? SPERM COMPETITION AND SEXUAL CONFLICT IN SEA
Publisher: Wiley
Date: 11-2007
DOI: 10.1111/J.1558-5646.2007.00232.X
Abstract: Our view of sperm competition is largely shaped by game-theoretic models based on external fertilizers. External fertilization is of particular interest as it is the ancestral mode of reproduction and as such, relevant to the evolution and maintenance of anisogamy (i.e., large eggs and tiny, numerous sperm). Current game-theoretic models have been invaluable in generating predictions of male responses to sperm competition in a range of internal fertilizers but these models are less relevant to marine broadcast spawners, the most common and archetypal external fertilizers. Broadcast spawners typically have incomplete fertilization due to sperm limitation and/or polyspermy (too many sperm), but the effects of incomplete (<100% fertilization rates) fertilization on game-theoretic predictions are unclear particular with regards to polyspermy. We show that incorporating the effects of sperm concentration on fertilization success changes the predictions of a classic game-theoretic model, dramatically reversing the relationship between sperm competition and the evolutionarily stable sperm release strategy. Furthermore, our results suggest that male and female broadcast spawners are likely to be in conflict at both ends of the sperm environment continuum rather than only in conditions of excess sperm as previously thought. Across the majority of the parameter space we explored, males release either too little to too much sperm for females to achieve complete fertilization. This conflict could result in a coevolutionary race that may have led to the evolution of internal fertilization in marine organisms.
Ocean zoning within a sparing versus sharing framework
Publisher: Springer Science and Business Media LLC
Date: 12-01-2018
Planning marine reserve networks for both feature representation and demographic persistence using connectivity patterns
Publisher: Public Library of Science (PLoS)
Date: 11-05-2016
Fire management for biodiversity conservation: Key research questions and our capacity to answer them
Publisher: Elsevier BV
Date: 09-2010
Covert rewilding: Modelling the detection of an unofficial translocation of Tasmanian devils to the Australian mainland
Publisher: Wiley
Date: 30-12-2020
DOI: 10.1111/CONL.12787
Abstract: Covert rewilding is the secret and illegal translocation of species in the pursuit of conservation objectives. Recent history contains multiple covert rewilding events, frequently occurring after official permission was denied. In order to better understand the phenomenon, I formulate covert rewilding as an optimisation problem, with the goal of creating a population that is too large to be eradicated once it is detected. I then consider a hypothetical covert rewilding of Tasmanian devils Sarcophilus harrisii to the Australian mainland. Three different release locations would allow a covert devil population to remain undetected for years, by which time its size and distribution may preclude eradication. Optimal release locations also represent optimal locations for official surveillance, but a more effective approach to halting covert rewilding could be a more permissive stance towards legal rewilding.
Resolving future fire management conflicts using multicriteria decision making
Publisher: Wiley
Date: 02-11-2016
DOI: 10.1111/COBI.12580
Abstract: Management strategies to reduce the risks to human life and property from wildfire commonly involve burning native vegetation. However, planned burning can conflict with other societal objectives such as human health and bio ersity conservation. These conflicts are likely to intensify as fire regimes change under future climates and as growing human populations encroach farther into fire-prone ecosystems. Decisions about managing fire risks are therefore complex and warrant more sophisticated approaches than are typically used. We applied a multicriteria decision making approach (MCDA) with the potential to improve fire management outcomes to the case of a highly populated, bio erse, and flammable wildland-urban interface. We considered the effects of 22 planned burning options on 8 objectives: house protection, maximizing water quality, minimizing carbon emissions and impacts on human health, and minimizing declines of 5 distinct species types. The MCDA identified a small number of management options (burning forest adjacent to houses) that performed well for most objectives, but not for one species type (arboreal mammal) or for water quality. Although MCDA made the conflict between objectives explicit, resolution of the problem depended on the weighting assigned to each objective. Additive weighting of criteria traded off the arboreal mammal and water quality objectives for other objectives. Multiplicative weighting identified scenarios that avoided poor outcomes for any objective, which is important for avoiding potentially irreversible bio ersity losses. To distinguish reliably among management options, future work should focus on reducing uncertainty in outcomes across a range of objectives. Considering management actions that have more predictable outcomes than landscape fuel management will be important. We found that, where data were adequate, an MCDA can support decision making in the complex and often conflicted area of fire management.
Prioritizing global conservation efforts
Publisher: Springer Science and Business Media LLC
Date: 03-2006
DOI: 10.1038/NATURE04366
Abstract: One of the most pressing issues facing the global conservation community is how to distribute limited resources between regions identified as priorities for bio ersity conservation. Approaches such as bio ersity hotspots, endemic bird areas and ecoregions are used by international organizations to prioritize conservation efforts globally. Although identifying priority regions is an important first step in solving this problem, it does not indicate how limited resources should be allocated between regions. Here we formulate how to allocate optimally conservation resources between regions identified as priorities for conservation--the 'conservation resource allocation problem'. Stochastic dynamic programming is used to find the optimal schedule of resource allocation for small problems but is intractable for large problems owing to the "curse of dimensionality". We identify two easy-to-use and easy-to-interpret heuristics that closely approximate the optimal solution. We also show the importance of both correctly formulating the problem and using information on how investment returns change through time. Our conservation resource allocation approach can be applied at any spatial scale. We demonstrate the approach with an ex le of optimal resource allocation among five priority regions in Wallacea and Sundaland, the transition zone between Asia and Australasia.
Barometer of Life: More Action, Not More Data
Publisher: American Association for the Advancement of Science (AAAS)
Date: 09-07-2010
Phenotype–environment mismatches reduce connectivity in the sea
Publisher: Wiley
Date: 21-12-2009
DOI: 10.1111/J.1461-0248.2009.01408.X
Abstract: The connectivity of marine populations is often surprisingly lower than predicted by the dispersal capabilities of propagules alone. Estimates of connectivity, moreover, do not always scale with distance and are sometimes counterintuitive. Population connectivity requires more than just the simple exchange of settlers among populations: it also requires the successful establishment and reproduction of exogenous colonizers. Marine organisms often disperse over large spatial scales, encountering very different environments and suffering extremely high levels of post-colonization mortality. Given the growing evidence that such selection pressures often vary over spatial scales that are much smaller than those of dispersal, we argue that selection will bias survival against exogenous colonizers. We call this selection against exogenous colonizers a phenotype-environment mismatch and argue that phenotype-environment mismatches represent an important barrier to connectivity in the sea. Crucially, these mismatches may operate independently of distance and thereby have the potential to explain the counterintuitive patterns of connectivity often seen in marine environments. We discuss how such mismatches might alter our understanding and management of marine populations.
General rules for environmental management to prioritise social ecological systems research based on a value of information approach
Publisher: Wiley
Date: 12-06-2019
A novel method for estimating the number of species within a region
Publisher: The Royal Society
Date: 22-03-2014
Abstract: Ecologists are often required to estimate the number of species in a region or designated area. A number of ersity indices are available for this purpose and are based on s ling the area using quadrats or other means, and estimating the total number of species from these s les. In this paper, a novel theory and method for estimating the number of species is developed. The theory involves the use of the Laplace method for approximating asymptotic integrals. The method is shown to be successful by testing random simulated datasets. In addition, several real survey datasets are tested, including forests that contain a large number (tens to hundreds) of tree species, and an aquatic system with a large number of fish species. The method is shown to give accurate results, and in almost all cases found to be superior to existing tools for estimating ersity.
Turing patterns in a diffusive Holling–Tanner predator-prey model with an alternative food source for the predator
Publisher: Elsevier BV
Date: 08-2021
Australia’s mammal fauna requires a strategic and enhanced network of predator-free havens
Publisher: Springer Science and Business Media LLC
Date: 15-01-2018
Effective conservation planning requires learning and adaptation
Publisher: Wiley
Date: 08-09-2010
DOI: 10.1890/080151
Author Correction: The population sizes and global extinction risk of reef-building coral species at biogeographic scales
Publisher: Springer Science and Business Media LLC
Date: 16-03-2021
Can culling a threatened species increase its chance of persisting?
Publisher: Elsevier BV
Date: 02-2007
Limitations of outsourcing on-the-ground biodiversity conservation
Publisher: Wiley
Date: 10-08-2016
DOI: 10.1111/COBI.12739
Abstract: To counteract global species decline, modern bio ersity conservation engages in large projects, spends billions of dollars, and includes many organizations working simultaneously within regions. To add to this complexity, the conservation sector has hierarchical structure, where conservation actions are often outsourced by funders (foundations, government, etc.) to local organizations that work on-the-ground. In contrast, conservation science usually assumes that a single organization makes resource allocation decisions. This discrepancy calls for theory to understand how the expected bio ersity outcomes change when interactions between organizations are accounted for. Here, we used a game theoretic model to explore how bio ersity outcomes are affected by vertical and horizontal interactions between 3 conservation organizations: a funder that outsourced its actions and 2 local conservation organizations that work on-the-ground. Interactions between the organizations changed the spending decisions made by in idual organizations, and thereby the magnitude and direction of the conservation benefits. We showed that funders would struggle to incentivize recipient organizations with set priorities to perform desired actions, even when they control substantial amounts of the funding and employ common contracting approaches to enhance outcomes. Instead, bio ersity outcomes depended on priority alignment across the organizations. Conservation outcomes for the funder were improved by strategic interactions when organizational priorities were well aligned, but decreased when priorities were misaligned. Meanwhile, local organizations had improved outcomes regardless of alignment due to additional funding in the system. Given that conservation often involves the aggregate actions of multiple organizations with different objectives, strategic interactions between organizations need to be considered if we are to predict possible outcomes of conservation programs or costs of achieving conservation targets.
Finite conservation funds mean triage is unavoidable
Publisher: Elsevier BV
Date: 04-2009
Resilient reefs may exist, but can larval dispersal models find them?
Publisher: Public Library of Science (PLoS)
Date: 22-08-2018
How to build an efficient conservation fence: Contributed paper
Publisher: Wiley
Date: 15-01-2010
DOI: 10.1111/J.1523-1739.2009.01291.X
Abstract: Barriers are used to achieve erse objectives in conservation and biosecurity. In conservation management, fences are often erected to exclude introduced predators and to contain diseased animals or invasive species. Planning an efficient conservation fence involves a number of decisions, including the size and design of the enclosure. We formulated the first general framework for building a fence that minimizes long-term management costs by balancing the expense of constructing a more secure barrier against the costs of coping with more frequent failures. The approach systematically considers the range of potential solutions to a well-defined fencing problem and results in a solution that maximizes conservation return on investment. We illustrated this method by designing efficient fences to address two different conservation goals: exclusion of invasive predators from populations of threatened eastern barred bandicoots (Perameles gunnii) and maintenance of isolated populations of healthy Tasmanian devils (Sarcophilus harrisii). A systematic approach to conservation fencing allows the best fence design to be chosen quantitatively and defensibly. It also facilitates conservation decisions at a strategic level by allowing fencing to be compared transparently with alternative conservation management actions.
Choosing cost-effective locations for conservation fences in the local landscape
Publisher: CSIRO Publishing
Date: 2012
DOI: 10.1071/WR11106
Abstract: Context Exclosure fences are widely used to reintroduce locally extinct animals. These fences function either as permanent landscape-scale areas free from most predators, or as small-scale temporary acclimatisation areas for newly translocated in iduals to be ‘soft released’ into the wider landscape. Existing research can help managers identify the best design for their exclosure fence, but there are currently no methods available to help identify the optimal location for these exclosures in the local landscape (e.g. within a property). Aims We outline a flexible decision-support tool that can help managers choose the best location for a proposed exclosure fence. We applied this method to choose the site of a predator-exclusion fence within the proposed Lorna Glen (Matuwa) Conservation Park in the rangelands of central Western Australia. Methods The decision was subject to a set of economic, ecological and political constraints that were applied sequentially. The final exclosure fence location, chosen from among those sites that satisfied the constraints, optimised conservation outcomes by maximising the area enclosed. Key results From a prohibitively large set of potential exclosure locations, the series of constraints reduced the number of candidates down to 32. When ranked by the total area enclosed, one exclosure location was clearly superior. Conclusions By describing the decision-making process explicitly and quantitatively, and systematically considering each of the candidate solutions, our approach identifies an efficient exclosure fence location via a repeatable and transparent process. Implications The construction of an exclusion fence is an expensive management option, and therefore needs to convincingly demonstrate a high expected return-on-investment. A systematic approach for choosing the location of an exclosure fence provides managers with a decision that can be justified to funding sources and stakeholders.
Estimating physiological tolerances - a comparison of traditional approaches to nonlinear regression techniques
Publisher: The Company of Biologists
Date: 2013
DOI: 10.1242/JEB.085712
Abstract: Traditionally, physiologists have estimated the ability of organisms to withstand lower partial pressures of oxygen by estimating the partial pressure at which oxygen consumption begins to decrease (known as the 'critical Po2' or 'Pc'). For almost 30 years, the principal way in which Pc has been estimated has been via piecewise 'broken stick' regression. Broken stick regression (BSR) was a useful approach when more sophisticated analyses were less available, but BSR makes a number of unsupported assumptions about the underlying form of the relationship between the rate of oxygen consumption and oxygen availability. The BSR approach also distils a range of values into a single point with no estimate of error. In accordance with more general calls to fit functions to continuous data, we propose the use of nonlinear regression (NLR) to fit various curvilinear functions to oxygen consumption data in order to estimate Pc. Importantly, our approach is back-compatible so that data collected using traditional methods in earlier studies can be compared to data collected using our technique. When we compared the performance of our approach relative to the traditional BSR approach for real world and simulated data, we found that under realistic circumstances, the NLR was more accurate and provided more powerful hypothesis tests. We recommend that future studies make use of NLR to estimate Pc, and also suggest that this approach might be more appropriate for a range of physiological studies that use BSR currently.
Costs are not necessarily correlated with threats in conservation landscapes
Publisher: Wiley
Date: 08-07-2019
DOI: 10.1111/CONL.12663
Simple rules can guide whether land- or ocean-based conservation will best benefit marine ecosystems
Publisher: Public Library of Science (PLoS)
Date: 06-09-2017
Superadditive and subadditive dynamics are not inherent to the types of interacting threat
Publisher: Cold Spring Harbor Laboratory
Date: 16-01-2019
DOI: 10.1101/522755
Abstract: Species and ecosystems usually face more than one threat. The damage caused by these multiple threats can accumulate nonlinearly: either subadditively, when the joint damage of combined threats is less than the damages of both threats in idually added together, or superadditively, when the joint damage is greater than the two in idual damages added together. These additivity dynamics are commonly attributed to the nature of the threatening processes, but conflicting empirical observations challenge this assumption. Here, we use a theoretical model to demonstrate that the additivity of threats can change with different magnitudes of threat impacts (effect of a threat on the population parameter, like growth rate). We use a harvested single-species population model to integrate the effects of multiple threats on equilibrium abundance. Our results reveal that threats do not always display consistent additive behavior, even in simple systems. Instead, their additivity depends on the magnitudes of the impacts of two threats, and the population parameter that is impacted by each threat. In our model specifically, when multiple threats have a low impact on the growth rate of a population, they display superadditive dynamics. In contrast, threats that impact the species’ carrying capacity are always additive or subadditive. These dynamics can be understood by reference to the curvature of the relationship between a given population parameter (e.g., growth) and equilibrium population size. Our results suggest that management actions can achieve lified benefits if they target low- litude threats that affect the growth rate, since these will be in a superadditive phase. More generally, our results suggest that cumulative impact theory should focus more than previously on the magnitude of the impact on the population parameter, and should be cautious about attributing additive dynamics to particular threat combinations.
Hyperstability masks declines in bumphead parrotfish (Bolbometopon muricatum) populations
Publisher: Springer Science and Business Media LLC
Date: 31-03-2016
Models that predict ecosystem impacts of reintroductions should consider uncertainty and distinguish between direct and indirect effects
Publisher: Elsevier BV
Date: 04-2016
Modelling the effects of leaky predator-exclusion fences and their surrounding halo
Publisher: Cold Spring Harbor Laboratory
Date: 16-08-2019
DOI: 10.1101/737924
Abstract: Terrestrial fauna of the southern hemisphere, particularly Australia and New Zealand, have suffered significant declines and extinctions due to predation by introduced red foxes Vulpes vulpes and cats Felis catus . Predator-exclusion fences offer protection to these threatened species and allow their populations to persist and even flourish within their boundaries. These fences have traditionally been designed to stop the movement of both the invasive predators (into the fence), and the native animals (out of the fence). However, recent theory and evidence suggest that when native animals are able to move across the fence, they can create a population beyond the fence boundary. This phenomena has been called a “halo effect”, and has the potential to both expand the direct and indirect benefits of predator-exclusion fences, and to reduce their negative effects. However, the conditions under which such an effect can be achieved are uncertain. They include questions about which native species could support a meaningful halo, what levels of predation outside the fence can be tolerated, and how permeable the fence would need to be. Here, we formulate this problem as both a simple two-patch model and a spatial partial differential equation model. We use the two approaches to explore the conditions under which a halo can deliver conservation benefits, and offer clear insights into the problem.
Individual variation in marine larval‐fish swimming speed and the emergence of dispersal kernels
Publisher: Wiley
Date: 08-12-2021
DOI: 10.1111/OIK.08896
Abstract: Dispersal emerges as a consequence of how an in idual's phenotype interacts with the environment. Not all dispersing in iduals have the same phenotype, and variation among in iduals can generate complex variation in the distribution of dispersal distances and directions. While active locomotion performance is an obvious candidate for a dispersal phenotype, its effects on dispersal are difficult to measure or predict, especially in small organisms dispersing in wind or currents. Therefore, we analyzed the effects of larval swimming on dispersal and settlement of coral‐reef fish larvae using a high‐resolution biophysical model. The model is, to date, the only biophysical model of marine larval dispersal that has been statistically validated against genetic parentage estimates of larval origin and destination, and incorporates empirically‐estimated larval behaviors and their ontogeny. Larval swimming, in combination with depth, orientation and navigation behaviors, actually reduced dispersal distances compared to those of passive larvae. Swimming had no consistent effects on long distance dispersal, but increased the spread of settlement locations. Swimming speed, in contrast, did not consistently affect median dispersal distances, but faster swimming larvae had greater mean and maximum dispersal distances than slower swimming larvae. Finally, faster larval swimming speeds consistently increased the probability of settlement. Our analysis shows how larval swimming differentially affects multiple properties of dispersal kernels. In doing so, it indicates how selection could favor faster larval swimming to increase settlement and local retention, which may actually result in longer dispersal distances as a by‐product of larvae trying to locate habitat rather than to disperse greater distances.
Efficiently locating conservation boundaries: Searching for the Tasmanian devil facial tumour disease front
Publisher: Elsevier BV
Date: 07-2009
Effective conservation requires clear objectives and prioritizing actions, not places or species
Publisher: Proceedings of the National Academy of Sciences
Date: 03-08-2015
Evaluating conservation spending for species return: A retrospective analysis in California
Publisher: Wiley
Date: 06-2009
Species Differences Drive Nonneutral Structure in Pleistocene Coral Communities
Publisher: University of Chicago Press
Date: 11-2012
DOI: 10.1086/667892
Abstract: Although ecological assemblages frequently depart from neutral model predictions, these discrepancies have not been unambiguously attributed to neutral theory's core assumption: that community structure is primarily the result of chance variation in birth, death, speciation, and dispersal, rather than the manifestation of demographic differences among species. Using coral communities in Barbados from four time periods during the Pleistocene, we demonstrate that the neutral theory cannot explain coral community similarity distributions, species' regional abundance distributions, or their local occupancy. Furthermore, discrepancies between the neutral theory and the observed communities can be attributed to violation of the core assumption of species equivalence. In particular, species' variable growth rates are driving departures from neutral predictions. Our results reinforce an understanding of reef coral community assembly that invokes trade-offs in species' demographic strategies. The results further suggest that conservation management actions will fail if they are based on the neutral assumption that different coral species are equally able to create live coral cover in the shallow-water reef environment. These findings highlight the importance of developing bio ersity theory that can parsimoniously incorporate species differences in coral reef communities, rather than further elaborating neutral theory.
Modelling the spread and control of cherry guava on Lord Howe Island
Publisher: Elsevier BV
Date: 11-2018
Regulating land use in the catchment of the Great Barrier Reef
Publisher: Elsevier BV
Date: 04-2022
Choosing optimal trigger points for ex situ, in toto conservation of single population threatened species
Publisher: Cold Spring Harbor Laboratory
Date: 08-01-2021
DOI: 10.1101/2021.01.08.425867
Abstract: Many endangered species exist in only a single population, and almost all species that go extinct will do so from their last remaining population. Understanding how to best conserve these single population threatened species (SPTS) is therefore a distinct and important task for threatened species conservation science. As a last resort, managers of SPTS may consider taking the entire population into captivity – ex situ, in toto conservation. In the past, this choice has been taken to the great benefit of the SPTS, but it has also lead to catastrophe. Here, we develop a decision-support tool for planning when to trigger this difficult action. Our method considers the uncertain and ongoing decline of the SPTS, the possibility that drastic ex situ action will fail, and the opportunities offered by delaying the decision. Specifically, these benefits are additional time for ongoing in situ actions to succeed, and opportunities for the managers to learn about the system. To illustrate its utility, we apply the decision tool to four retrospective case-studies of declining SPTS. As well as offering support to this particular decision, our tool illustrates why trigger points for difficult conservation decisions should be formulated in advance, but must also be adaptive. A trigger-point for the ex situ, in toto conservation of a SPTS, for ex le, will not take the form of a simple threshold abundance.
Minimizing the Cost of Keeping Options Open for Conservation in a Changing Climate
Publisher: Wiley
Date: 29-01-2014
DOI: 10.1111/COBI.12238
Abstract: Policy documents advocate that managers should keep their options open while planning to protect coastal ecosystems from climate-change impacts. However, the actual costs and benefits of maintaining flexibility remain largely unexplored, and alternative approaches for decision making under uncertainty may lead to better joint outcomes for conservation and other societal goals. For ex le, keeping options open for coastal ecosystems incurs opportunity costs for developers. We devised a decision framework that integrates these costs and benefits with probabilistic forecasts for the extent of sea-level rise to find a balance between coastal ecosystem protection and moderate coastal development. Here, we suggest that instead of keeping their options open managers should incorporate uncertain sea-level rise predictions into a decision-making framework that evaluates the benefits and costs of conservation and development. In our ex le, based on plausible scenarios for sea-level rise and assuming a risk-neutral decision maker, we found that substantial development could be accommodated with negligible loss of environmental assets. Characterization of the Pareto efficiency of conservation and development outcomes provides valuable insight into the intensity of trade-offs between development and conservation. However, additional work is required to improve understanding of the consequences of alternative spatial plans and the value judgments and risk preferences of decision makers and stakeholders.
Superadditive and subadditive dynamics are not inherent to the types of interacting threat
Publisher: Public Library of Science (PLoS)
Date: 23-08-2019
Evolutionary consequences of fertilization mode for reproductive phenology and asynchrony
Publisher: Inter-Research Science Center
Date: 14-10-2015
DOI: 10.3354/MEPS11453
Bigger or better: The relative benefits of protected area network expansion and enforcement for the conservation of an exploited species
Publisher: Wiley
Date: 10-01-2018
DOI: 10.1111/CONL.12433
Degrees of population-level susceptibility of Australian terrestrial non-volant mammal species to predation by the introduced red fox (Vulpes vulpes) and feral cat (Felis catus)
Publisher: CSIRO Publishing
Date: 2018
DOI: 10.1071/WR18008
Abstract: Context Over the last 230 years, the Australian terrestrial mammal fauna has suffered a very high rate of decline and extinction relative to other continents. Predation by the introduced red fox (Vulpes vulpes) and feral cat (Felis catus) is implicated in many of these extinctions, and in the ongoing decline of many extant species. Aims To assess the degree to which Australian terrestrial non-volant mammal species are susceptible at the population level to predation by the red fox and feral cat, and to allocate each species to a category of predator susceptibility. Methods We collated the available evidence and complemented this with expert opinion to categorise each Australian terrestrial non-volant mammal species (extinct and extant) into one of four classes of population-level susceptibility to introduced predators (i.e. ‘extreme’, ‘high’, ‘low’ or ‘not susceptible’). We then compared predator susceptibility with conservation status, body size and extent of arboreality and assessed changes in the occurrence of species in different predator-susceptibility categories between 1788 and 2017. Key results Of 246 Australian terrestrial non-volant mammal species (including extinct species), we conclude that 37 species are (or were) extremely predator-susceptible 52 species are highly predator-susceptible 112 species are of low susceptibility and 42 species are not susceptible to predators. Confidence in assigning species to predator-susceptibility categories was strongest for extant threatened mammal species and for extremely predator-susceptible species. Extinct and threatened mammal species are more likely to be predator-susceptible than Least Concern species arboreal species are less predator-susceptible than ground-dwelling species and medium-sized species (35 g–3.5kg) are more predator-susceptible than smaller or larger species. Conclusions The effective control of foxes and cats over large areas is likely to assist the population-level recovery of ~63 species – the number of extant species with extreme or high predator susceptibility – which represents ~29% of the extant Australian terrestrial non-volant mammal fauna. Implications Categorisation of predator susceptibility is an important tool for conservation management, because the persistence of species with extreme susceptibility will require intensive management (e.g. predator-proof exclosures or predator-free islands), whereas species of lower predator susceptibility can be managed through effective landscape-level suppression of introduced predators.
Returns from matching management resolution to ecological variation in a coral reef fishery
Publisher: The Royal Society
Date: 16-03-2016
Abstract: When managing heterogeneous socioecological systems, decision-makers must choose a spatial resolution at which to define management policies. Complex spatial policies allow managers to better reflect underlying ecological and economic heterogeneity, but incur higher compliance and enforcement costs. To choose the most appropriate management resolution, we need to characterize the relationship between management resolution and performance. We parameterize a model of the commercial coral trout fishery in the Great Barrier Reef, Australia, which is currently managed by a single, spatially homogeneous management policy. We use this model to estimate how the spatial resolution of management policies affect the amount of revenue generated, and assess whether a more spatially complex policy can be justified. Our results suggest that economic variation is likely to be a more important source of heterogeneity than ecological differences, and that the majority of this variation can be captured by a relatively simple spatial management policy. Moreover, while an increase in policy resolution can improve performance, the location of policy changes also needs to align with ecological and socioeconomic variation. Interestingly, the highly complex process of larval dispersal, which plays a critical ecological role in coral reef ecosystem dynamics, may not demand equally complex management policies.
Interior fences can reduce cost and uncertainty when eradicating invasive species from large islands
Publisher: Wiley
Date: 19-07-2013
How conservation initiatives go to scale
Publisher: Springer Science and Business Media LLC
Date: 07-10-2019
Conservation Planning with Multiple Organizations and Objectives,Planificación de la Conservación con Múltiples Organizaciones y Objetivos
Publisher: Wiley
Date: 12-2011
DOI: 10.1111/J.1523-1739.2010.01610.X
Abstract: There has been a dramatic increase in the number of conservation organizations worldwide. It is now common for multiple organizations to operate in the same landscape in pursuit of different conservation goals. New objectives, such as maintenance of ecosystem services, will attract additional funding and new organizations to conservation. Systematic conservation planning helps in the design of spatially explicit management actions that optimally conserve multiple landscape features (e.g., species, ecosystems, or ecosystem services). But the methods used in its application implicitly assume that a single actor implements the optimal plan. We investigated how organizational behavior and conservation outcomes are affected by the presence of autonomous implementing organizations with different objectives. We used simulation models and game theory to explore how alternative behaviors (e.g., organizations acting independently or explicitly cooperating) affected an organization's ability to protect their feature of interest, and investigated how the distribution of features in the landscape influenced organizations' attitudes toward cooperation. Features with highly correlated spatial distributions, although typically considered an opportunity for mutually beneficial conservation planning, can lead to organizational interactions that result in lower levels of protection. These detrimental outcomes can be avoided by organizations that cooperate when acquiring land. Nevertheless, for cooperative purchases to benefit both organizations' objectives, each must forgo the protection of land parcels that they would consider to be of high conservation value. Transaction costs incurred during cooperation and the sources of conservation funding could facilitate or hinder cooperative behavior.
Prioritising the eradication of invasive species from island archipelagos with high reinvasion risk
Publisher: Cold Spring Harbor Laboratory
Date: 05-11-2021
DOI: 10.1101/2021.11.04.467372
Abstract: Eradicating invasive species from islands is a proven method for safeguarding threatened and endangered species from extinction. Island eradications can deliver lasting benefits, but require large up-front expenditure of limited conservation resources. The choice of islands must therefore be prioritised. Numerous tools have been developed to prioritise island eradications, but none fully account for the risk of those eradicated species later returning to the island: reinvasion. In this paper, we develop a prioritisation method for island eradications that accounts for the complexity of the reinvasion process. By merging spatially-explicit metapopulation modelling with stochastic dynamic optimisation techniques, we construct a decision-support tool that optimises conservation outcomes in the presence of reinvasion risk. We applied this tool to two different case studies – rat ( Rattus rattus ) invasions in the Seaforth archipelago in New Zealand, and cane toad ( Rhinella marina ) invasions in the D ier archipelago in Australia – to illustrate how state-dependent optimal policies can maximise expected conservation gains. In both case studies, incorporating reinvasion risk dramatically altered the optimal order of island eradications, and improved the potential conservation benefits. The increase in benefits was larger in D ier than Seaforth (42% improvement versus 6%), as a consequence of both the characteristics of the invasive species, and the arrangement of the islands. Our results illustrate the potential consequences of ignoring reinvasion risk, and demonstrate that including reinvasion in eradication prioritisation can dramatically improve conservation outcomes.
Protecting Biodiversity when Money Matters: Maximizing Return on Investment
Publisher: Public Library of Science (PLoS)
Date: 30-01-2008
A connectivity portfolio effect stabilizes marine reserve performance
Publisher: Proceedings of the National Academy of Sciences
Date: 28-09-2020
Abstract: Networks of no-take marine reserves support local fisheries by ensuring a consistent supply of juvenile fish. We measured larval dispersal patterns for a highly exploited coral grouper and quantified temporal fluctuations in the recruitment contribution from a network of no-take marine reserves on the Great Barrier Reef. Although recruitment contributions from in idual reserves are extremely variable, the reserve network generates a connectivity portfolio effect that successfully d ens the volatility of larval supply to nearby coral reefs. Our findings demonstrate that effective reserve networks can yield previously unrecognized stabilizing benefits that ensure a consistent replenishment of exploited fish stocks.
The spatial footprint and patchiness of large‐scale disturbances on coral reefs
Publisher: Wiley
Date: 14-08-2021
DOI: 10.1111/GCB.15805
Abstract: Ecosystems have always been shaped by disturbances, but many of these events are becoming larger, more severe and more frequent. The recovery capacity of depleted populations depends on the frequency of disturbances, the spatial distribution of mortality and the scale of dispersal. Here, we show that four mass coral bleaching events on the Great Barrier Reef (in 1998, 2002, 2016 and 2017) each had markedly larger disturbance footprints and were less patchy than a severe category 5 tropical cyclone (Cyclone Yasi, 2011). Severely bleached reefs in 2016 and 2017 were isolated from the nearest lightly affected reefs by up to 146 and 200 km, respectively. In contrast, reefs damaged by Cyclone Yasi were on average 20 km away from relatively undisturbed reefs, well within the estimated range of larval dispersal for most corals. Based on these results, we present a model of coral reef disturbance and recovery to examine (1) how the spatial clustering of disturbances modifies large‐scale recovery rates and (2) how recovery rates are shaped by species' dispersal abilities. Our findings illustrate that the spatial footprint of the recent mass bleaching events poses an unprecedented threat to the resilience of coral species in human history, a threat that is even larger than the amount of mortality suggests.
Surrogates for reef fish connectivity when designing marine protected area networks
Publisher: Inter-Research Science Center
Date: 15-10-2012
DOI: 10.3354/MEPS09924
Successful validation of a larval dispersal model using genetic parentage data
Publisher: Public Library of Science (PLoS)
Date: 12-07-2019
Prioritising the eradication of invasive species from island archipelagos with high reinvasion risk
Publisher: Wiley
Date: 27-09-2022
Abstract: Eradicating invasive species from islands is a proven method for safeguarding threatened and endangered species from extinction. Island eradications can deliver lasting benefits, but require large up‐front expenditure of limited conservation resources. The choice of islands must therefore be prioritised. Numerous tools have been developed to prioritise island eradications, but none fully account for the risk of those eradicated species later returning to the island: reinvasion. In this paper, we develop a prioritisation method for island eradications that accounts for the complexity of the reinvasion process. By merging spatially explicit metapopulation modelling with stochastic dynamic optimisation techniques, we construct a decision‐support tool that optimises conservation outcomes in the presence of reinvasion risk. We applied this tool to two different case studies—rat ( Rattus rattus ) invasions in the Seaforth archipelago in New Zealand, and cane toad ( Rhinella marina ) invasions in the D ier archipelago in Australia—to illustrate how state‐dependent optimal policies can maximise expected conservation gains. In both case studies, incorporating reinvasion risk dramatically altered the optimal order of island eradications, and improved the potential conservation benefits. The increase in benefits was larger in D ier than Seaforth (42% improvement versus 6%), as a consequence of both the characteristics of the invasive species, and the arrangement of the islands. Synthesis and applications . Our results illustrate the potential consequences of ignoring reinvasion risk. We recommend that reinvasion risk be explicitly included in any island eradication prioritisation involving an archipelago, particularly when some islands are close to the mainland.
Underestimating the benefits of marine protected areas for the replenishment of fished populations
Publisher: Wiley
Date: 02-07-2019
DOI: 10.1002/FEE.2075
Reproductive hyperallometry and managing the world’s fisheries
Publisher: Proceedings of the National Academy of Sciences
Date: 16-08-2021
Abstract: We find that a ubiquitous assumption in fisheries models for predicting population replenishment introduces systematic overestimates of replenishment in fished populations. For 32 of the world’s major fisheries, these biases result in harvest thresholds being set too high: in most cases, reference points based on spawning potential ratios are more than 2.5 times higher than those necessary to achieve the desired level of replenishment. When we use the more biologically appropriate assumption of reproductive hyperallometry, we find that management tools such as spatiotemporal closures and harvest slots can outperform traditional approaches in terms of yield. Failing to consider reproductive hyperallometry overestimates the efficacy of traditional fisheries management and underestimates the benefits of approaches that create reservoirs of larger in iduals.
Systematic planning can rapidly close the protection gap in Australian mammal havens
Publisher: Wiley
Date: 2019
DOI: 10.1111/CONL.12611
Modeling dynamics of native and invasive species to guide prioritization of management actions
Publisher: Wiley
Date: 05-2017
DOI: 10.1002/ECS2.1822
Eradicating down the food chain: optimal multispecies eradication schedules for a commonly encountered invaded island ecosystem
Publisher: Wiley
Date: 17-04-2015
The need for speed: Informed land acquisitions for conservation in a dynamic property market
Publisher: Wiley
Date: 02-10-2008
DOI: 10.1111/J.1461-0248.2008.01226.X
Abstract: Land acquisition is a common approach to bio ersity conservation but is typically subject to property availability on the public market. Consequently, conservation plans are often unable to be implemented as intended. When properties come on the market, conservation agencies must make a choice: purchase immediately, often without a detailed knowledge of its bio ersity value survey the parcel and accept the risk that it may be removed from the market during this process or not purchase and hope a better parcel comes on the market at a later date. We describe both an optimal method, using stochastic dynamic programming, and a simple rule of thumb for making such decisions. The solutions to this problem illustrate how optimal conservation is necessarily dynamic and requires explicit consideration of both the time period allowed for implementation and the availability of properties.
Different dispersal abilities allow reef fish to coexist
Publisher: Proceedings of the National Academy of Sciences
Date: 19-09-2011
Abstract: The coexistence of multiple species on a smaller number of limiting resources is an enduring ecological paradox. The mechanisms that maintain such bio ersity are of great interest to ecology and of central importance to conservation. We describe and prove a unique and robust mechanism for coexistence: Species that differ only in their dispersal abilities can coexist, if habitat patches are distributed at irregular distances. This mechanism is straightforward and ecologically intuitive, but can nevertheless create complex coexistence patterns that are robust to substantial environmental stochasticity. The Great Barrier Reef (GBR) is noted for its ersity of reef fish species and its complex arrangement of reef habitat. We demonstrate that this mechanism can allow fish species with different pelagic larval durations to stably coexist in the GBR. Further, coexisting species on the GBR often dominate different subregions, defined primarily by cross-shelf position. Interspecific differences in dispersal ability generate similar coexistence patterns when dispersal is influenced by larval behavior and variable oceanographic conditions. Many marine and terrestrial ecosystems are characterized by patchy habitat distributions and contain coexisting species that have different dispersal abilities. This coexistence mechanism is therefore likely to have ecological relevance beyond reef fish.
Inferring extinctions from sighting records of variable reliability
Publisher: Wiley
Date: 19-08-2013
Reply to: Conclusions of low extinction risk for most species of reef-building corals are premature
Publisher: Springer Science and Business Media LLC
Date: 14-02-2022
Improving private land conservation with outcome-based biodiversity payments
Publisher: Wiley
Date: 21-02-2018
Havens for threatened Australian mammals: the contributions of fenced areas and offshore islands to the protection of mammal species susceptible to introduced predators
Publisher: CSIRO Publishing
Date: 2018
DOI: 10.1071/WR17172
Abstract: Context Many Australian mammal species are highly susceptible to predation by introduced domestic cats (Felis catus) and European red foxes (Vulpes vulpes). These predators have caused many extinctions and have driven large distributional and population declines for many more species. The serendipitous occurrence of, and deliberate translocations of mammals to, ‘havens’ (cat- and fox-free offshore islands, and mainland fenced exclosures capable of excluding cats and foxes) has helped avoid further extinction. Aims The aim of this study was to conduct a stocktake of current island and fenced havens in Australia and assess the extent of their protection for threatened mammal taxa that are most susceptible to cat and fox predation. Methods Information was collated from erse sources to document (1) the locations of havens and (2) the occurrence of populations of predator-susceptible threatened mammals (naturally occurring or translocated) in those havens. The list of predator-susceptible taxa (67 taxa, 52 species) was based on consensus opinion from mammal experts. Key results Seventeen fenced and 101 island havens contain 188 populations of 38 predator-susceptible threatened mammal taxa (32 species). Island havens cover a larger cumulative area than fenced havens (2152km2 versus 346km2), and reach larger sizes (largest island 325km2, with another island of 628km2 becoming available from 2018 largest fence: 123km2). Islands and fenced havens contain similar numbers of taxa (27 each), because fenced havens usually contain more taxa per haven. Populations within fences are mostly translocated (43 of 49 88%). Islands contain translocated populations (30 of 139 22%) but also protect in situ (109) threatened mammal populations. Conclusions Havens are used increasingly to safeguard threatened predator-susceptible mammals. However, 15 such taxa occur in only one or two havens, and 29 such taxa (43%) are not represented in any havens. The taxon at greatest risk of extinction from predation, and in greatest need of a haven, is the central rock-rat (Zyzomys pedunculatus). Implications Future investment in havens should focus on locations that favour taxa with no (or low) existing haven representation. Although havens can be critical for avoiding extinctions in the short term, they cover a minute proportion of species’ former ranges. Improved options for controlling the impacts of cats and foxes at landscape scales must be developed and implemented.
Optimal dynamic allocation of conservation funding among priority regions
Publisher: Springer Science and Business Media LLC
Date: 20-08-2008
DOI: 10.1007/S11538-008-9343-0
Abstract: The optimal allocation of conservation resources between bio erse conservation regions has generally been calculated using stochastic dynamic programming, or using myopic heuristics. These solutions are hard to interpret and may not be optimal. To overcome these two limitations, this paper approaches the optimal conservation resource allocation problem using optimal control theory. A solution using Pontryagin's maximum principle provides novel insight into the general properties of efficient conservation resource allocation strategies, and allows more extensive testing of the performance of myopic heuristics. We confirmed that a proposed heuristic (minimize short-term loss) yields near-optimal results in complex allocation situations, and found that a qualitative allocation feature observed in previous analyses (bang-bang allocation) is a general property of the optimal allocation strategy.
Trade-Offs in Identifying Global Conservation Priority Areas
Publisher: Wiley
Date: 03-08-2010
Prioritizing Trade-Offs in Conservation
Publisher: Wiley
Date: 03-08-2010
Placing invasive species management in a spatiotemporal context
Publisher: Wiley
Date: 04-2016
DOI: 10.1890/15-0095
Abstract: Invasive species are a worldwide issue, both ecologically and economically. A large body of work focuses on various aspects of invasive species control, including how to allocate control efforts to eradicate an invasive population as cost effectively as possible: There are a erse range of invasive species management problems, and past mathematical analyses generally focus on isolated ex les, making it hard to identify and understand parallels between the different contexts. In this study, we use a single spatiotemporal model to tackle the problem of allocating control effort for invasive species when suppressing an island invasive species, and for long-term spatial suppression projects. Using feral cat suppression as an illustrative ex le, we identify the optimal resource allocation for island and mainland suppression projects. Our results demonstrate how using a single model to solve different problems reveals similar characteristics of the solutions in different scenarios. As well as illustrating the insights offered by linking problems through a spatiotemporal model, we also derive novel and practically applicable results for our case studies. For temporal suppression projects on islands, we find that lengthy projects are more cost effective and that rapid control projects are only economically cost effective when population growth rates are high or diminishing returns on control effort are low. When suppressing invasive species around conservation assets (e.g., national parks or exclusion fences), we find that the size of buffer zones should depend on the ratio of the species growth and spread rate.
Habitat vulnerability in conservation planning-when it matters and how much
Publisher: Wiley
Date: 12-2010
Waiting can be an optimal conservation strategy, even in a crisis discipline
Publisher: Proceedings of the National Academy of Sciences
Date: 11-09-2017
Abstract: Every year, more species are driven to extinction by the combined pressures of habitat destruction, invasive species, and climate change. These ongoing losses have created a “crisis culture” in conservation, where project funds are spent as soon as they are received. We challenge this orthodoxy and demonstrate how strategic delays can improve efficiency. Waiting can allow agencies to leverage additional benefits from their funds, through investment, capacity building, or monitoring and research. With the right amount of delay, limited conservation resources can protect more species. Surprisingly, they can even do so in less time. Our results suggest that, in addition to their current focus on where to target resources, conservation managers should carefully choose when to spend these funds.
Conserving Biodiversity Efficiently: What to Do, Where, and When
Publisher: Public Library of Science (PLoS)
Date: 21-08-2007
Cost-efficient fenced reserves for conservation: Single large or two small?
Publisher: Wiley
Date: 10-2014
DOI: 10.1890/13-1579.1
Abstract: Fences that exclude alien invasive species are used to reduce predation pressure on reintroduced threatened wildlife. Planning these continuously managed systems of reserves raises an important extension of the Single Large or Several Small (SLOSS) reserve planning framework: the added complexity of ongoing management. We investigate the long-term cost-efficiency of a single large or two small predator exclusion fences in the arid Australian context of reintroducing bilbies Macrotis lagotis, and we highlight the broader significance of our results with sensitivity analysis. A single fence more frequently results in a much larger net cost than two smaller fences. We find that the cost-efficiency of two fences is robust to strong demographic and environmental uncertainty, which can help managers to mitigate the risk of incurring high costs over the entire life of the project.
Spatial congruence between biodiversity and ecosystem services in South Africa
Publisher: Elsevier BV
Date: 03-2009
Estimating dispersal kernels using genetic parentage data
Publisher: Wiley
Date: 23-11-2018
Cost-effective conservation decisions are robust to uncertainty in the species–area relationship
Publisher: Proceedings of the National Academy of Sciences
Date: 17-02-2009
Resolving conflicts in fire management using decision theory: asset-protection versus biodiversity conservation
Publisher: Wiley
Date: 08-2010
Net benefit and cost-effectiveness of universal iron-containing multiple micronutrient powders for young children in 78 countries: a microsimulation study
Publisher: Elsevier BV
Date: 08-2020
Dynamic marine protected areas can improve the resilience of coral reef systems
Publisher: Wiley
Date: 08-11-2009
DOI: 10.1111/J.1461-0248.2009.01384.X
Abstract: Marine Protected Areas are usually static, permanently closed areas. There are, however, both social and ecological reasons to adopt dynamic closures, where reserves move through time. Using a general theoretical framework, we investigate whether dynamic closures can improve the mean biomass of herbivorous fishes on reef systems, thereby enhancing resilience to undesirable phase-shifts. At current levels of reservation (10-30%), moving protection between all reefs in a system is unlikely to improve herbivore biomass, but can lead to a more even distribution of biomass. However, if protected areas are rotated among an appropriate subset of the entire reef system (e.g. rotating 10 protected areas between only 20 reefs in a 100 reef system), dynamic closures always lead to increased mean herbivore biomass. The management strategy that will achieve the highest mean herbivore biomass depends on both the trajectories and rates of population recovery and decline. Given the current large-scale threats to coral reefs, the ability of dynamic marine protected areas to achieve conservation goals deserves more attention.
Reef-fish larval dispersal patterns validate no-take marine reserve network connectivity that links human communities
Publisher: Springer Science and Business Media LLC
Date: 23-03-2017
The relative conservation impact of strategies that prioritize biodiversity representation, threats, and protection costs
Publisher: Wiley
Date: 29-05-2020
DOI: 10.1111/CSP2.221
The context dependence of frontier versus wilderness conservation priorities
Publisher: Wiley
Date: 07-02-2019
DOI: 10.1111/CONL.12632
Developmental cost theory predicts thermal environment and vulnerability to global warming
Publisher: Springer Science and Business Media LLC
Date: 02-03-2020
Dispersal of grouper larvae drives local resource sharing in a coral reef fishery
Publisher: Elsevier BV
Date: 04-2013
DOI: 10.1016/J.CUB.2013.03.006
Abstract: In many tropical nations, fisheries management requires a community-based approach because small customary marine tenure areas define the spatial scale of management [1]. However, the fate of larvae originating from a community's tenure is unknown, and thus the degree to which a community can expect their management actions to replenish the fisheries within their tenure is unclear [2, 3]. Furthermore, whether and how much larval dispersal links tenure areas can provide a strong basis for cooperative management [4, 5]. Using genetic parentage analysis, we measured larval dispersal from a single, managed spawning aggregation of squaretail coral grouper (Plectropomus areolatus) and determined its contribution to fisheries replenishment within five community tenure areas up to 33 km from the aggregation at Manus Island, Papua New Guinea. Within the community tenure area containing the aggregation, 17%-25% of juveniles were produced by the aggregation. In four adjacent tenure areas, 6%-17% of juveniles were from the aggregation. Larval dispersal kernels predict that 50% of larvae settled within 14 km of the aggregation. These results strongly suggest that both local and cooperative management actions can provide fisheries benefits to communities over small spatial scales.
A conservation planning approach to mitigate the impacts of leakage from protected area networks
Publisher: Wiley
Date: 11-12-2014
DOI: 10.1111/COBI.12434
Abstract: Protected area networks are designed to restrict anthropogenic pressures in areas of high bio ersity. Resource users respond by seeking to replace some or all of the lost resources from locations elsewhere in the landscape. Protected area networks thereby perturb the pattern of human pressures by displacing extractive effort from within protected areas into the broader landscape, a process known as leakage. The negative effects of leakage on conservation outcomes have been empirically documented and modeled using homogeneous descriptions of conservation landscapes. Human resource use and bio ersity vary greatly in space, however, and a theory of leakage must describe how this heterogeneity affects the magnitude, pattern, and bio ersity impacts of leakage. We combined models of household utility, adaptive human foraging, and bio ersity conservation to provide a bioeconomic model of leakage that accounts for spatial heterogeneity. Leakage had strong and ergent impacts on the performance of protected area networks, undermining bio ersity benefits but mitigating the negative impacts on local resource users. When leakage was present, our model showed that poorly designed protected area networks resulted in a substantial net loss of bio ersity. However, the effects of leakage can be mitigated if they are incorporated ex-ante into the conservation planning process. If protected areas are coupled with nonreserve policy instruments such as market subsidies, our model shows that the trade-offs between bio ersity and human well-being can be further and more directly reduced.
Ensemble ecosystem modeling for predicting ecosystem response to predator reintroduction
Publisher: Wiley
Date: 14-12-2016
DOI: 10.1111/COBI.12798
Abstract: Introducing a new or extirpated species to an ecosystem is risky, and managers need quantitative methods that can predict the consequences for the recipient ecosystem. Proponents of keystone predator reintroductions commonly argue that the presence of the predator will restore ecosystem function, but this has not always been the case, and mathematical modeling has an important role to play in predicting how reintroductions will likely play out. We devised an ensemble modeling method that integrates species interaction networks and dynamic community simulations and used it to describe the range of plausible consequences of 2 keystone-predator reintroductions: wolves (Canis lupus) to Yellowstone National Park and dingoes (Canis dingo) to a national park in Australia. Although previous methods for predicting ecosystem responses to such interventions focused on predicting changes around a given equilibrium, we used Lotka-Volterra equations to predict changing abundances through time. We applied our method to interaction networks for wolves in Yellowstone National Park and for dingoes in Australia. Our model replicated the observed dynamics in Yellowstone National Park and produced a larger range of potential outcomes for the dingo network. However, we also found that changes in small vertebrates or invertebrates gave a good indication about the potential future state of the system. Our method allowed us to predict when the systems were far from equilibrium. Our results showed that the method can also be used to predict which species may increase or decrease following a reintroduction and can identify species that are important to monitor (i.e., species whose changes in abundance give extra insight into broad changes in the system). Ensemble ecosystem modeling can also be applied to assess the ecosystem-wide implications of other types of interventions including assisted migration, biocontrol, and invasive species eradication.
Confronting the risks of large-scale invasive species control
Publisher: Springer Science and Business Media LLC
Date: 23-05-2017
Larval dispersal and fishing pressure influence recruitment in a coral reef fishery
Publisher: Wiley
Date: 28-09-2021
Abstract: Understanding larval connectivity patterns in exploited fishes is a fundamental prerequisite for developing effective management strategies and assessing the vulnerability of a fishery to recruitment overfishing and localised extinction. To date, however, researchers have not considered how regional variations in fishing pressure also influence recruitment. We used genetic parentage analyses and modelling to infer the dispersal patterns of bumphead parrotfish Bolbometopon muricatum larvae in the Kia fishing grounds, Isabel Province, Solomon Islands. We then extrapolated our Kia dispersal model to a regional scale by mapping the available nursery and adult habitat for B. muricatum in six regions in the western Solomon Islands, and estimated the relative abundance of adult B. muricatum populations in each of these regions based on available adult habitat and historical and current fishing pressure. Parentage analysis identified 67 juveniles that were the offspring of parents s led in the Kia fishing grounds. A fitted larval dispersal kernel predicted that 50% of larvae settled within 30 km of their parents, and 95% settled within 85 km of their parents. After accounting for uns led adults, our model predicted that 34% of recruitment to the Kia fishery was spawned locally. Extrapolating the spatial resolution of the model revealed that a high proportion of the larvae recruiting into the Kia fishing grounds came from nearby regions that had abundant adult populations. Other islands in the archipelago provided few recruits to the Kia fishing grounds, reflecting the greater distances to these islands and lower adult abundances in some regions. Synthesis and applications . This study shows how recruitment into a coral reef fishery is influenced by larval dispersal patterns and regional variations in historical fishing pressure. The scales of larval connectivity observed for bumphead parrotfish indicate that recruitment overfishing is unlikely if there are lightly exploited reefs up to 85 km away from a heavily fished region, and that small ( km 2 ) marine‐protected areas (MPAs) are insufficient to protect this species. We recommend greater efforts to understand the interactions between larval dispersal and gradients of fishing pressure, as this will enable the development of tailored fisheries management strategies.
Larval dispersal reveals regional sources and sinks in the Great Barrier Reef
Publisher: Inter-Research Science Center
Date: 16-02-2006
DOI: 10.3354/MEPS308017
A guide to ecosystem models and their environmental applications
Publisher: Springer Science and Business Media LLC
Date: 14-09-2020
Modeling total predation to avoid perverse outcomes from cat control in a data‐poor island ecosystem
Publisher: Wiley
Date: 24-08-2022
DOI: 10.1111/COBI.13916
Abstract: Data‐hungry, complex ecosystem models are often used to predict the consequences of threatened species management, including perverse outcomes. Unfortunately, this approach is impractical in the many systems that have insufficient data to parameterize ecosystem interactions or reliably calibrate or validate such models. We devised a different approach composed of a minimum realistic model that guides decisions in data‐ and resource‐scarce systems. We applied our approach to a case study in an invaded ecosystem from Christmas Island, Australia, where there are concerns that cat ( Felis catus ) eradication to protect native species, including the red‐tailed tropicbird ( Phaethon rubricauda ), could release mesopredation by invasive rats ( Rattus rattus ). We used biophysical constraints (metabolic demand) and observable parameters (e.g., prey preferences) to identify the combined cat and rat abundances that could threaten the tropicbird population. The population of tropicbirds was not sustained when predated by 1607 rats (95% credible interval [CI]: 103–5910) in the absence of cats and 21 cats (95% CI: 2–82) in the absence of rats. For every cat removed from the island, the bird's net population growth rate improved, provided rats did not increase by more than 77 in iduals (95% CI: 30–174). Thus, in this context, 1 cat is equivalent to 30–174 rats. Our methods are especially useful for on‐the‐ground predator control in the absence of knowledge of predator–predator interactions to determine whether current abundance of predators threatened the prey population of interest managing only 1 predator species was sufficient to protect the prey species given potential release of another predator and control of multiple predator species was needed to meet the conservation goal. With our approach limited information can be used for maximum value in data‐poor systems because it shifts the focus from predicting future trajectories to identifying conditions that impede conservation.
The population sizes and global extinction risk of reef-building coral species at biogeographic scales
Publisher: Springer Science and Business Media LLC
Date: 03-2021
DOI: 10.1038/S41559-021-01393-4
Abstract: Knowledge of a species' abundance is critically important for assessing its risk of extinction, but for the vast majority of wild animal and plant species such data are scarce at biogeographic scales. Here, we estimate the total number of reef-building corals and the population sizes of more than 300 in idual species on reefs spanning the Pacific Ocean bio ersity gradient, from Indonesia to French Polynesia. Our analysis suggests that approximately half a trillion corals (0.3 × 10
Designing an expert-led Bayesian network to understand interactions between policy instruments for adoption of eco-friendly farming practices
Publisher: Elsevier BV
Date: 03-2023
A polyphagous, tropical insect herbivore shows strong seasonality in age-structure and longevity independent of temperature and host availability
Publisher: Springer Science and Business Media LLC
Date: 06-2021
DOI: 10.1038/S41598-021-90960-7
Abstract: Bactrocera tryoni is a polyphagous fruit fly that is predicated to have continuous breeding in tropical and subtropical Australia as temperature and hosts are not limiting. Nevertheless, in both rainforest and tropical agricultural systems, the fly shows a distinct seasonal phenology pattern with an autumn decline and a spring emergence. Temperature based population models have limited predictive capacity for this species and so the driver(s) for the observed phenology patterns are unknown. Using a demographic approach, we studied the age-structure of B. tryoni populations in subtropical Australia in an agricultural system, with a focus on times of the year when marked changes in population abundance occur. We found that the age-structure of the population varied with season: summer and autumn populations were composed of mixed-age flies, while late-winter and early-spring populations were composed of old to very old in iduals. When held at a constant temperature, the longevity of adult reference cohorts (obtained from field infested fruits) also showed strong seasonality the adults of spring and early autumn populations were short-lived, while late autumn and late winter adults were long-lived. While still expressing in modified landscapes, the data strongly suggests that B. tryoni has an endogenous mechanism which would have allowed it to cope with changes in the breeding resources available in its endemic monsoonal rainforest habitat, when fruits would have been abundant in the late spring and summer (wet season), and rare or absent during late autumn and winter (dry season).
IUNS. 21st International Congress of Nutrition. Buenos Aires, Argentina, October 15-20, 2017: Abstracts
Publisher: S. Karger AG
Date: 2017
DOI: 10.1159/000480486
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