Peter Macreadie

Correction to ‘Blue Carbon stocks of Great Barrier Reef deep-water seagrasses’

Publisher: The Royal Society

Date: 2020

DOI: 10.1098/RSBL.2019.0784

Multi-scale mapping of Australia’s terrestrial and blue carbon stocks and their continental and bioregional drivers

Publisher: Springer Science and Business Media LLC

Date: 06-2023

DOI: 10.1038/S43247-023-00838-X

Abstract: The soil in terrestrial and coastal blue carbon ecosystems is an important carbon sink. National carbon inventories require accurate assessments of soil carbon in these ecosystems to aid conservation, preservation, and nature-based climate change mitigation strategies. Here we harmonise measurements from Australia’s terrestrial and blue carbon ecosystems and apply multi-scale machine learning to derive spatially explicit estimates of soil carbon stocks and the environmental drivers of variation. We find that climate and vegetation are the primary drivers of variation at the continental scale, while ecosystem type, terrain, clay content, mineralogy and nutrients drive subregional variations. We estimate that in the top 0–30 cm soil layer, terrestrial ecosystems hold 27.6 Gt (19.6–39.0 Gt), and blue carbon ecosystems 0.35 Gt (0.20–0.62 Gt). Tall open eucalypt and mangrove forests have the largest soil carbon content by area, while eucalypt woodlands and hummock grasslands have the largest total carbon stock due to the vast areas they occupy. Our findings suggest these are essential ecosystems for conservation, preservation, emissions avoidance, and climate change mitigation because of the additional co-benefits they provide.

Methane emissions from agricultural ponds are underestimated in national greenhouse gas inventories

Publisher: Springer Science and Business Media LLC

Date: 05-12-2022

DOI: 10.1038/S43247-022-00638-9

Abstract: Agricultural ponds have some of the highest methane emissions per area among freshwater systems, and these anthropogenic emissions should be included in national greenhouse gas inventories. Here we deliver a continental-scale assessment of methane emissions from agricultural ponds in the United States and Australia. We source maps of agricultural ponds, compile a meta-analysis for their emissions and use published data to correct for temperature and the relative contributions of two methane fluxes (diffusion and ebullition). In the United States, 2.56 million agricultural ponds cover 420.9 kha and emit about 95.8 kt year −1 of methane. In Australia, 1.76 million agricultural ponds cover 291.2 kha and emit about 75.1 kt year −1 of methane. Despite large uncertainties, our findings suggest that small water bodies emit twice as much methane than is currently accounted for in national inventories. Managing these systems can reduce these emissions while benefiting productivity, ecosystem services, and bio ersity.

Prioritising the restoration of marine and coastal ecosystems using ecosystem accounting

Publisher: Research Square Platform LLC

Date: 10-05-2022

DOI: 10.21203/RS.3.RS-1617940/V1

Abstract: Ecosystem accounting is a structured approach to compiling environmental and economic information. While accounts are typically used to compile data on past trends, they have an unrealised capacity to also be used to inform decisions by providing a structured approach to scenario evaluation of potential futures. We used the global standard for ecosystem accounting (System for Environmental Economic Accounting), to examine past trends and potential future restoration options in two large metropolitan bays, where data existed for tidal marshes, mangroves and seagrass. We assessed options for reversing the loss of these ecosystems and although the net benefit varied between sites, we found that if all sites were restored, the overall investment-benefit ratio would be 10.5, resulting from AUD$100 million of ecosystem services from an investment of AUD$8.5 million. This study highlights the advantage of structured approaches to data compilation through ecosystem accounts, and consideration of ecosystem dynamics and response to restoration actions, to inform management decisions.

Comment on ‘Geoengineering with seagrasses: is credit due where credit is given?’

Publisher: IOP Publishing

Date: 02-2018

DOI: 10.1088/1748-9326/AAA7AD

Characterizing the first wave of fish and invertebrate colonization on a new offshore petroleum platform

Publisher: Oxford University Press (OUP)

Date: 05-05-2019

DOI: 10.1093/ICESJMS/FSZ077

Abstract: Offshore Oil & Gas (O& G) infrastructure creates artificial reef complexes that support marine communities in oceans. No studies have characterized the first wave of colonization, which can reveal information about habitat attraction and ecological connectivity. Here we used opportunistically-collected industrial Remotely Operated Vehicles (ROVs) to investigate fish and invertebrate colonization on a new North Sea O& G platform and trenching of an associated pipeline. We observed rapid colonization of fish communities, with increases in species richness (S), abundance (N), and ersity (H′) over the first four days (the entire study period). By contrast, there was minimal change in motile invertebrate communities over the survey period. After trenching, invertebrate S, N and H′ decreased significantly, whilst fish S, N and H′ increased. This study is the first to report on the pioneer wave of fish and invertebrate colonization on O& G infrastructure, thereby providing rare insight into formation of new reef communities in the sea. These short and opportunistic data are valuable in terms of showing what can be discovered from analysis of ‘pre-installation’ ROV footage of O& G structures, of which there are terabytes of data held by O& G companies waiting to be analyzed by environmental scientists.

The application of Unmanned Aerial Vehicles (UAVs) to estimate above-ground biomass of mangrove ecosystems

Publisher: Elsevier BV

Date: 06-2020

DOI: 10.1016/J.RSE.2020.111747

Optimal soil carbon sampling designs to achieve cost-effectiveness: a case study in blue carbon ecosystems

Publisher: The Royal Society

Date: 09-2018

DOI: 10.1098/RSBL.2018.0416

Abstract: Researchers are increasingly studying carbon (C) storage by natural ecosystems for climate mitigation, including coastal ‘blue carbon’ ecosystems. Unfortunately, little guidance on how to achieve robust, cost-effective estimates of blue C stocks to inform inventories exists. We use existing data (492 cores) to develop recommendations on the s ling effort required to achieve robust estimates of blue C. Using a broad-scale, spatially explicit dataset from Victoria, Australia, we applied multiple spatial methods to provide guidelines for reducing variability in estimates of soil C stocks over large areas. With a separate dataset collected across Australia, we evaluated how many s les are needed to capture variability within soil cores and the best methods for extrapolating C to 1 m soil depth. We found that 40 core s les are optimal for capturing C variance across 1000's of kilometres but higher density s ling is required across finer scales (100–200 km). Accounting for environmental variation can further decrease required s ling. The within core analyses showed that nine s les within a core capture the majority of the variability and log-linear equations can accurately extrapolate C. These recommendations can help develop standardized methods for s ling programmes to quantify soil C stocks at national scales.

Characterizing the second wave of fish and invertebrate colonization of an offshore petroleum platform

Publisher: Oxford University Press (OUP)

Date: 21-02-2021

DOI: 10.1093/ICESJMS/FSAA245

Abstract: Offshore Oil and Gas (O& G) infrastructure affords structurally complex hard substrata in otherwise featurless areas of the seafloor. Opportunistically collected industrial ROV imagery was used to investigate the colonization of a petroleum platform in the North Sea 1–2 years following installation. Compared to pre-construction communities and pioneering colonizers, we documented 48 additional taxa, including a rare sighting of a pompano (Trachinotus ovatus). The second wave of motile colonizers presented greater ersity than the pioneering community. Occurrence of species became more even over the 2 years following installation, with species occurring in more comparable abundances. No on-jacket sessile taxa were recorded during first-wave investigations however, 17 sessile species were detected after 1 year (decreasing to 16 after 2). Motile species were found to favour structurally complex sections of the jacket (e.g. mudmat), while sessile organisms favoured exposed elements. Evidence of on-jacket reproduction was found for two commercially important invertebrate species - common whelk (Buccinum undatum) and European squid (Loligo vulgaris). Moreover, abundance of larvae-producing species experience an 8.5-fold increase over a 2-year period compared to baseline communities. These findings may have implications for decommissioning and resource-management strategies, suggesting that a case-by-case reviewing approach should be favoured over the most common “one size fits all”.

Punching above their weight: Large release of greenhouse gases from small agricultural dams

Publisher: Wiley

Date: 20-11-2018

DOI: 10.1111/GCB.14477

Abstract: Freshwater ecosystems play a major role in global carbon cycling through the breakdown of organic material and release of greenhouse gases (GHGs). Carbon dioxide (CO

Author Correction: The future of Blue Carbon science (Nature Communications, (2019), 10, 1, (3998), 10.1038/s41467-019-11693-w)

Publisher: Springer Science and Business Media LLC

Date: 08-11-2019

DOI: 10.1038/S41467-019-13126-0

Abstract: An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Identifying spatio‐temporal trends in seagrass meadows to inform future restoration

Publisher: Wiley

Date: 11-10-2023

DOI: 10.1111/REC.13787

Abstract: Seagrass restoration requires information on a range of factors including site environmental conditions, appropriate planting techniques, and the identification of sites most likely to support seagrass. To address the question of where to focus restoration efforts, a key first step is to identify trends in the spatio‐temporal distribution of seagrasses to identify areas of persistence, loss, and recent gains. Areas of recent recovery (and adjacent areas), can then be targeted by practitioners for assisted recovery and restoration, whilst areas of persistent loss can be avoided. Here we identified the contemporary distribution, density, and species composition of seagrass ecosystems (using Sentinel 2 imagery and supervised object‐based imagery analysis) and integrated these data with historic extents to identify spatio‐temporal trends in seagrass distribution in Western Port, Victoria, Australia. Contemporary classifications demonstrated acceptable accuracies (Overall Accuracy 0.77–0.85, User Accuracy 0.76–0.97) and predicted a contemporary seagrass extent of 222 km 2 with 48 km 2 of low‐density recovery predicted to have occurred since 1999. Comparisons with historical seagrass extents indicated some seagrass recovery since large‐scale losses in 1983, although some areas of loss were also present. Recovery included a net gain of approximately 95 km 2 in the past 20 years and an eastward range expansion suggesting environmental conditions have improved and are now conducive for restoration efforts in some areas. Results demonstrate that accurate, low‐cost, remote sensing of seagrass ecosystems is possible and show how understanding spatio‐temporal trends can guide the spatial allocation of resources by prioritizing areas for restoration where recovery is beginning to occur.

Current and future carbon stocks in coastal wetlands within the Great Barrier Reef catchments

Publisher: Wiley

Date: 04-05-2021

DOI: 10.1111/GCB.15642

Abstract: Australia's Great Barrier Reef (GBR) catchments include some of the world's most intact coastal wetlands comprising erse mangrove, seagrass and tidal marsh ecosystems. Although these ecosystems are highly efficient at storing carbon in marine sediments, their soil organic carbon (SOC) stocks and the potential changes resulting from climate impacts, including sea level rise are not well understood. For the first time, we estimated SOC stocks and their drivers within the range of coastal wetlands of GBR catchments using boosted regression trees (i.e. a machine learning approach and ensemble method for modelling the relationship between response and explanatory variables) and identified the potential changes in future stocks due to sea level rise. We found levels of SOC stocks of mangrove and seagrass meadows have different drivers, with climatic variables such as temperature, rainfall and solar radiation, showing significant contributions in accounting for variation in SOC stocks in mangroves. In contrast, soil type accounted for most of the variability in seagrass meadows. Total SOC stock in the GBR catchments, including mangroves, seagrass meadows and tidal marshes, is approximately 137 Tg C, which represents 9%–13% of Australia's total SOC stock while encompassing only 4%–6% of the total extent of Australian coastal wetlands. In a global context, this could represent 0.5%–1.4% of global SOC stock. Our study suggests that landward migration due to projected sea level rise has the potential to enhance carbon accumulation with total carbon gains between 0.16 and 0.46 Tg C and provides an opportunity for future restoration to enhance blue carbon.

Fencing farm dams to exclude livestock halves methane emissions and improves water quality

Publisher: Wiley

Date: 07-06-2022

DOI: 10.1111/GCB.16237

Abstract: Agricultural practices have created tens of millions of small artificial water bodies (“farm dams” or “agricultural ponds”) to provide water for domestic livestock worldwide. Among freshwater ecosystems, farm dams have some of the highest greenhouse gas (GHG) emissions per m 2 due to fertilizer and manure run‐off boosting methane production—an extremely potent GHG. However, management strategies to mitigate the substantial emissions from millions of farm dams remain unexplored. We tested the hypothesis that installing fences to exclude livestock could reduce nutrients, improve water quality, and lower aquatic GHG emissions. We established a large‐scale experiment spanning 400 km across south‐eastern Australia where we compared unfenced ( N = 33) and fenced farm dams ( N = 31) within 17 livestock farms. Fenced farm dams recorded 32% less dissolved nitrogen, 39% less dissolved phosphorus, 22% more dissolved oxygen, and produced 56% less diffusive methane emissions than unfenced dams. We found no effect of farm dam management on diffusive carbon dioxide emissions and on the organic carbon in the soil. Dissolved oxygen was the most important variable explaining changes in carbon fluxes across dams, whereby doubling dissolved oxygen from 5 to 10 mg L −1 led to a 74% decrease in methane fluxes, a 124% decrease in carbon dioxide fluxes, and a 96% decrease in CO 2 ‐eq (CH 4 + CO 2 ) fluxes. Dams with very high dissolved oxygen ( mg L −1 ) showed a switch from positive to negative CO 2 ‐eq. (CO 2 + CH 4 ) fluxes (i.e., negative radiative balance), indicating a positive contribution to reduce atmospheric warming. Our results demonstrate that simple management actions can dramatically improve water quality and decrease methane emissions while contributing to more productive and sustainable farming.

Quantitative analysis of fish and invertebrate assemblage dynamics in association with a North Sea oil and gas installation complex

Publisher: Elsevier BV

Date: 11-2018

DOI: 10.1016/J.MARENVRES.2018.09.018

Abstract: Decommissioning of offshore infrastructure has become a major issue facing the global offshore energy industry. In the North Sea alone, the decommissioning liability is estimated at £40 billion by 2040. Current international policy requires removal of offshore infrastructure when their production life ends however, this policy is being questioned as emerging data reveal the importance of these structures to fish and invertebrate populations. Indeed, some governments are developing 'rigs-to-reef' (RTR) policies in situations where offshore infrastructure is demonstrated to have important environmental benefits. Using Remotely Operated Vehicles (ROVs), this study quantified and analysed fish and invertebrate assemblage dynamics associated with an oil and gas (O&G) complex in the Dogger Bank Special Area of Conservation (SAC), in the North Sea, Germany. We found clear depth zonation of organisms: infralittoral communities (0-15 m), circalittoral assemblages (15-45 m) and epi-benthic communities (45-50 m), which implies that 'topping' or 'toppling' decommissioning strategies could eliminate communities that are unique to the upper zones. Sessile invertebrate assemblages were significantly different between structures, which appeared to be driven by both biotic and abiotic mechanisms. The O&G complex accommodated erse and abundant motile invertebrate and fish assemblages within which the whelk Buccinium undatum, cod fish Gadus morhua and lumpsucker fish Cyclopterus lumpus used the infrastructure for different stages of reproduction. This observation of breeding implies that the structures may be producing more fish and invertebrates, as opposed to simply acting as sites of attraction (sensu the 'attraction vs production' debate). At present, there are no records of C. lumpus spawning at such depth and distance from the coast, and this is the first published evidence of this species using an offshore structure as a spawning site. Overall, this study provides important new insight into the role of offshore O&G structures as habitat for fish and invertebrates in the North Sea, thereby helping to inform decommissioning decisions.

A global map of mangrove forest soil carbon at 30 m spatial resolution

Publisher: IOP Publishing

Date: 30-04-2018

DOI: 10.1088/1748-9326/AABE1C

Carbon stocks, sequestration, and emissions of wetlands in south eastern Australia

Publisher: Wiley

Date: 24-06-2018

DOI: 10.1111/GCB.14319

Abstract: Nontidal wetlands are estimated to contribute significantly to the soil carbon pool across the globe. However, our understanding of the occurrence and variability of carbon storage between wetland types and across regions represents a major impediment to the ability of nations to include wetlands in greenhouse gas inventories and carbon offset initiatives. We performed a large-scale survey of nontidal wetland soil carbon stocks and accretion rates from the state of Victoria in south-eastern Australia-a region spanning 237,000 km

Mapping Ocean Wealth Australia: The value of coastal wetlands to people and nature

Publisher: The Nature Conservancy

Date: 25-11-2019

DOI: 10.21153/CARNELL2019MAPPING

Pathways for Understanding Blue Carbon Microbiomes with Amplicon Sequencing

Publisher: MDPI AG

Date: 26-10-2022

DOI: 10.3390/MICROORGANISMS10112121

Abstract: The capacity of Blue Carbon Ecosystems to act as carbon sinks is strongly influenced by the metabolism of soil-associated microbes, which ultimately determine how much carbon is accumulated or returned to the atmosphere. The rapid evolution of sequencing technologies has facilitated the generation of tremendous amounts of data on what taxa comprise belowground microbial assemblages, largely available as isolated datasets, offering an opportunity for synthesis research that informs progress on understanding Blue Carbon microbiomes. We identified questions that can be addressed with a synthesis approach, including the high variability across datasets, space, and time due to differing s ling techniques, ecosystem or vegetation specificity, and the relationship between microbiome community and edaphic properties, particularly soil carbon. To address these questions, we collated 34 16S rRNA licon sequencing datasets, including bulk soil or rhizosphere from seagrass, mangroves, and saltmarshes within publicly available repositories. We identified technical and theoretical challenges that precluded a synthesis of multiple studies with currently available data, and opportunities for addressing the knowledge gaps within Blue Carbon microbial ecology going forward. Here, we provide a standardisation toolbox that supports enacting tasks for the acquisition, management, and integration of Blue Carbon-associated sequencing data and metadata to potentially elucidate novel mechanisms behind Blue Carbon dynamics.

Dual indicators link geochemistry to microbiota in blue carbon soils

Publisher: Elsevier BV

Date: 05-2023

DOI: 10.1016/J.ECSS.2023.108307

Operationalizing marketable blue carbon

Publisher: Elsevier BV

Date: 05-2022

DOI: 10.1016/J.ONEEAR.2022.04.005

A global horizon scan of issues impacting marine and coastal biodiversity conservation.

Publisher: Springer Science and Business Media LLC

Date: 07-07-2022

DOI: 10.1038/S41559-022-01812-0

Abstract: The bio ersity of marine and coastal habitats is experiencing unprecedented change. While there are well-known drivers of these changes, such as overexploitation, climate change and pollution, there are also relatively unknown emerging issues that are poorly understood or recognized that have potentially positive or negative impacts on marine and coastal ecosystems. In this inaugural Marine and Coastal Horizon Scan, we brought together 30 scientists, policymakers and practitioners with transdisciplinary expertise in marine and coastal systems to identify new issues that are likely to have a significant impact on the functioning and conservation of marine and coastal bio ersity over the next 5-10 years. Based on a modified Delphi voting process, the final 15 issues presented were distilled from a list of 75 submitted by participants at the start of the process. These issues are grouped into three categories: ecosystem impacts, for ex le the impact of wildfires and the effect of poleward migration on equatorial bio ersity resource exploitation, including an increase in the trade of fish swim bladders and increased exploitation of marine collagens and new technologies, such as soft robotics and new biodegradable products. Our early identification of these issues and their potential impacts on marine and coastal bio ersity will support scientists, conservationists, resource managers and policymakers to address the challenges facing marine ecosystems.

Number pregnancy and low birth weight (LBW) babies in Anutapura Hospital in Palu City in 2016

Publisher: Elsevier BV

Date: 06-2020

DOI: 10.1016/J.ENFCLI.2019.10.072

Effects of elevated temperature on microbial breakdown of seagrass leaf and tea litter biomass

Publisher: Springer Science and Business Media LLC

Date: 31-10-2020

DOI: 10.1007/S10533-020-00715-1

Blue carbon as a natural climate solution

Publisher: Springer Science and Business Media LLC

Date: 11-2021

DOI: 10.1038/S43017-021-00224-1

A Continental-Scale Assessment of Density, Size, Distribution and Historical Trends of Farm Dams Using Deep Learning Convolutional Neural Networks

Publisher: MDPI AG

Date: 18-01-2021

DOI: 10.3390/RS13020319

Abstract: Farm dams are a ubiquitous limnological feature of agricultural landscapes worldwide. While their primary function is to capture and store water, they also have disproportionally large effects on bio ersity and biogeochemical cycling, with important relevance to several Sustainable Development Goals (SDGs). However, the abundance and distribution of farm dams is unknown in most parts of the world. Therefore, we used artificial intelligence and remote sensing data to address this critical global information gap. Specifically, we trained a deep learning convolutional neural network (CNN) on high-definition satellite images to detect farm dams and carry out the first continental-scale assessment on density, distribution and historical trends. We found that in Australia there are 1.765 million farm dams that occupy an area larger than Rhode Island (4678 km2) and store over 20 times more water than Sydney Harbour (10,990 GL). The State of New South Wales recorded the highest number of farm dams (654,983 37% of the total) and Victoria the highest overall density (1.73 dams km−2). We also estimated that 202,119 farm dams (11.5%) remain omitted from any maps, especially in South Australia, Western Australia and the Northern Territory. Three decades of historical records revealed an ongoing decrease in the construction rate of farm dams, from % per annum before 2000, to ~1% after 2000, to .05% after 2010—except in the Australian Capital Territory where rates have remained relatively high. We also found systematic trends in construction design: farm dams built in 2015 are on average 50% larger in surface area and contain 66% more water than those built in 1989. To facilitate sharing information on sustainable farm dam management with authorities, scientists, managers and local communities, we developed AusDams.org—a free interactive portal to visualise and generate statistics on the physical, environmental and ecological impacts of farm dams.

Nutrient input estimation and reduction strategies related to land use and landscape pattern (LULP) in a near-eutrophic coastal bay with a small watershed in the South China sea

Publisher: Elsevier BV

Date: 06-2021

DOI: 10.1016/J.OCECOAMAN.2021.105573

Blue Carbon stocks of Great Barrier Reef deep-water seagrasses

Publisher: The Royal Society

Date: 12-2018

DOI: 10.1098/RSBL.2018.0529

Abstract: Shallow-water seagrasses capture and store globally significant quantities of organic carbon (OC), often referred to as ‘Blue Carbon’ however, data are lacking on the importance of deep-water (greater than 15 m) seagrasses as Blue Carbon sinks. We compared OC stocks from deep-, mid- and shallow-water seagrasses at Lizard Island within the Great Barrier Reef (GBR) lagoon. We found deep-water seagrass ( Halophila species) contained similar levels of OC to shallow-water species (e.g. Halodule uninervis ) (0.64 ± 0.08% and 0.9 ± 0.1 mg C cm −3 , 0.87 ± 0.19% and 1.3 ± 0.3 mg C cm −3 , respectively), despite being much sparser and smaller in stature. Deep-water seagrass sediments contained significantly higher levels (approx. ninefold) of OC than surrounding bare areas. Inorganic carbon (CaCO 3 ) levels were relatively high in deep-water seagrass sediments (8.2 ± 0.4%) and, if precipitated from epiphytes within the meadow, could offset the potential CO 2 -sink capacity of these meadows. The δ 13 C signatures of sediment s les varied among depths and habitats (−10.9 and −17.0), reflecting contributions from autochthonous and allochthonous sources. If the OC stocks reported in this study are similar to deep-water Halophila meadows elsewhere within the GBR lagoon (total area 31 000 km 2 ), then OC bound within this system is roughly estimated at 27.4 million tonnes.

An Australian blue carbon method to estimate climate change mitigation benefits of coastal wetland restoration

Publisher: Wiley

Date: 30-06-2022

DOI: 10.1111/REC.13739

Abstract: Restoration of coastal wetlands has the potential to deliver both climate change mitigation, called blue carbon, and adaptation benefits to coastal communities, as well as supporting bio ersity and providing additional ecosystem services. Valuing carbon sequestration may incentivize restoration projects however, it requires development of rigorous methods for quantifying blue carbon sequestered during coastal wetland restoration. We describe the development of a blue carbon accounting model (BlueCAM) used within the Tidal Restoration of Blue Carbon Ecosystems Methodology Determination 2022 of the Emissions Reduction Fund (ERF), which is Australia's voluntary carbon market scheme. The new BlueCAM uses Australian data to estimate abatement from carbon and greenhouse gas sources and sinks arising from coastal wetland restoration (via tidal restoration) and aligns with the Intergovernmental Panel for Climate Change guidelines for national greenhouse gas inventories. BlueCAM includes carbon sequestered in soils and biomass and avoided emissions from alternative land uses. A conservative modeled approach was used to provide estimates of abatement (as opposed to on‐ground measurements) and in doing so, this will reduce the costs associated with monitoring and verification for ERF projects and may increase participation in blue carbon projects by Australian landholders. BlueCAM encompasses multiple climate regions and plant communities and therefore may be useful to others outside Australia seeking to value blue carbon benefits from coastal wetland restoration.

Combining gray and green infrastructure to improve coastal resilience: lessons learnt from hybrid flood defenses

Publisher: Informa UK Limited

Date: 09-05-2021

DOI: 10.1080/21664250.2021.1920278

Eutrophication reduces seagrass contribution to coastal food webs

Publisher: Wiley

Date: 06-2021

DOI: 10.1002/ECS2.3626

Abstract: Food sources and food web structure in seagrass meadows are important determinants of ecosystem functions and services. However, there is little information on the effect of eutrophication on food source contributions and food web structure in seagrass meadows. Here we used stable isotopes of carbon and nitrogen (δ 13 C and δ 15 N) to investigate how do different levels of nutrient enrichment affect the diets of consumers and food web structure within tropical seagrass meadows. We found that the diet contributions of macroalgae (mean 24% ± 12% for fish, 21% ± 5% for invertebrates), particulate organic matter (mean 19% ± 12% for fish, 18% ± 8% for invertebrates), and sediment organic matter (mean 24% ± 13% for fish, 21% ± 8% for invertebrates) to fish and invertebrates were all higher in seagrass meadows with higher nutrient concentrations, while seagrass and epiphytes contributed more to consumers in seagrass meadows with lower nutrient concentrations. Meanwhile, higher nutrient concentrations decreased the trophic position (mean 2.6 ± 0.5 in high‐nutrient level, 3.4 ± 0.6 in low‐nutrients level) of consumers and food chain length (2.5 in high‐nutrient level, 2.9 in low‐nutrients level). Higher nutrient concentrations reduced the contribution of seagrass carbon to consumers through the grazing food chain, but enhanced the flow of macroalgal carbon to consumers through the grazing food chain. Overall, eutrophication modified the food web structure of seagrass meadows. We recommend that measures be taken to decrease nutrient input into seagrass ecosystems to maintain its important functions and services.

The future of Blue Carbon science

Publisher: Springer Science and Business Media LLC

Date: 05-09-2019

DOI: 10.1038/S41467-019-11693-W

Abstract: The term Blue Carbon (BC) was first coined a decade ago to describe the disproportionately large contribution of coastal vegetated ecosystems to global carbon sequestration. The role of BC in climate change mitigation and adaptation has now reached international prominence. To help prioritise future research, we assembled leading experts in the field to agree upon the top-ten pending questions in BC science. Understanding how climate change affects carbon accumulation in mature BC ecosystems and during their restoration was a high priority. Controversial questions included the role of carbonate and macroalgae in BC cycling, and the degree to which greenhouse gases are released following disturbance of BC ecosystems. Scientists seek improved precision of the extent of BC ecosystems techniques to determine BC provenance understanding of the factors that influence sequestration in BC ecosystems, with the corresponding value of BC and the management actions that are effective in enhancing this value. Overall this overview provides a comprehensive road map for the coming decades on future research in BC science.

Response to Gallagher (2022)—the Australian Tidal Restoration for Blue Carbon method 2022—conservative, robust, and practical

Publisher: Wiley

Date: 28-09-2023

DOI: 10.1111/REC.14027

Mangrove and Saltmarsh Distribution Mapping and Land Cover Change Assessment for South-Eastern Australia from 1991 to 2015

Publisher: MDPI AG

Date: 08-04-2021

DOI: 10.3390/RS13081450

Abstract: Coastal wetland ecosystems, such as saltmarsh and mangroves, provide a wide range of important ecological and socio-economic services. A good understanding of the spatial and temporal distribution of these ecosystems is critical to maximising the benefits from restoration and conservation projects. We mapped mangrove and saltmarsh ecosystem transitions from 1991 to 2015 in south-eastern Australia, using remotely sensed Landsat data and a Random Forest classification. Our classification results were improved by the addition of two physical variables (Shuttle Radar Topographic Mission (SRTM), and Distance to Water). We also provide evidence that the addition of post-classification, spatial and temporal, filters improve overall accuracy of coastal wetlands detection by up to 16%. Mangrove and saltmarsh maps produced in this study had an overall User Accuracy of 0.82–0.95 and 0.81–0.87 and an overall Producer Accuracy of 0.71–0.88 and 0.24–0.87 for mangrove and saltmarsh, respectively. We found that mangrove ecosystems in south-eastern Australia have lost an area of 1148 ha (7.6%), whilst saltmarsh experienced an overall increase in coverage of 4157 ha (20.3%) over this 24-year period. The maps developed in this study allow local managers to quantify persistence, gains, and losses of coastal wetlands in south-eastern Australia.

Trends in the application of remote sensing in blue carbon science

Publisher: Wiley

Date: 09-2023

DOI: 10.1002/ECE3.10559

Response of Seagrass ‘Blue Carbon’ Stocks to Increased Water Temperatures

Publisher: MDPI AG

Date: 22-10-2018

DOI: 10.3390/D10040115

Abstract: Seagrass meadows are globally important sinks of ‘Blue Carbon’, but warming water temperatures due to climate change may undermine their capacity to sequester and retain organic carbon (Corg). We tested the effects of warming on seagrass Corg stocks in situ by transplanting seagrass soil cores along a thermal plume generated by a coal-fired power plant in a seagrass-dominated estuary (Lake Macquarie, Australia). Transplanted cores were subjected to temperatures 2 and 4 °C above ambient temperatures and Corg content was measured after 7, 30, 90 and 180 days. We were unable to detect any significant effect of warming on Corg concentration, stocks, chemical composition (as measured by labile, recalcitrant, refractory ratios), or microbial abundance at any time point. In fact, Corg levels were temporally variable. These findings contrast those of previous studies (mostly laboratory-based) that have reported increases in microbial remineralisation (breakdown) of Corg in response to warming. To explain the lack of any detectable warming effect, we suggest that higher temperatures, longer durations of warming exposure, or additional stressors (e.g., oxygen exposure) may be needed to overcome microbial activation barriers and stimulate Corg remineralisation.

Understanding the seagrass‐sediment‐light feedback to guide restoration planning: a case study using Zostera muelleri

Publisher: Wiley

Date: 24-10-2023

DOI: 10.1111/REC.14044

Modeled approaches to estimating blue carbon accumulation with mangrove restoration to support a blue carbon accounting method for Australia

Publisher: Wiley

Date: 11-01-2022

DOI: 10.1002/LNO.12014

Abstract: The development and refinement of methods for estimating organic carbon accumulation in biomass and soils during mangrove restoration and rehabilitation can encourage uptake of restoration projects for their ecosystem services, including those of climate change mitigation, or blue carbon. To support the development of a blue carbon method for Australia under the Emission Reduction Fund scheme we investigated (1) whether carbon accumulation data from natural mangroves could be used to estimate carbon accumulation during restoration (2) modeling mangrove biomass accumulation and (3) how modeled carbon accumulation could be achieved over heterogeneous sites. First, we assessed carbon accumulation in soil and biomass pools from the global literature, finding that estimating carbon accumulation using data from natural mangroves provided similar estimates as those for restored or rehabilitated mangroves. We assessed mangrove biomass accumulation from global chronosequence studies, which we used to develop regional models for estimating biomass accumulation with restoration in Australia using values from local natural mangroves. Estimating biomass carbon accumulation using site‐based means of stand biomass provided similar estimates as values estimated through use of regional means values stratified by elevation and reduced overestimates of biomass carbon accumulation that were based on regional mean values. Modeling soil carbon accumulation over environmentally heterogeneous project sites can apply a similar approach, stratifying over variation in site elevation. Our analysis provides a strategy for modeling blue carbon pools for an Australian blue carbon method that accommodates regional differences and is based on data from natural mangroves.

Australian vegetated coastal ecosystems as global hotspots for climate change mitigation

Publisher: Springer Science and Business Media LLC

Date: 02-10-2019

DOI: 10.1038/S41467-019-12176-8

Abstract: Policies aiming to preserve vegetated coastal ecosystems (VCE tidal marshes, mangroves and seagrasses) to mitigate greenhouse gas emissions require national assessments of blue carbon resources. Here, we present organic carbon (C) storage in VCE across Australian climate regions and estimate potential annual CO 2 emission benefits of VCE conservation and restoration. Australia contributes 5–11% of the C stored in VCE globally (70–185 Tg C in aboveground biomass, and 1,055–1,540 Tg C in the upper 1 m of soils). Potential CO 2 emissions from current VCE losses are estimated at 2.1–3.1 Tg CO 2 -e yr -1 , increasing annual CO 2 emissions from land use change in Australia by 12–21%. This assessment, the most comprehensive for any nation to-date, demonstrates the potential of conservation and restoration of VCE to underpin national policy development for reducing greenhouse gas emissions.

A horizon scan of priorities for coastal marine microbiome research

Publisher: Springer Science and Business Media LLC

Date: 21-10-2014

DOI: 10.1038/S41559-019-0999-7

Abstract: Research into the microbiomes of natural environments is changing the way ecologists and evolutionary biologists view the importance of microorganisms in ecosystem function. This is particularly relevant in ocean environments, where microorganisms constitute the majority of biomass and control most of the major biogeochemical cycles, including those that regulate Earth's climate. Coastal marine environments provide goods and services that are imperative to human survival and well-being (for ex le, fisheries and water purification), and emerging evidence indicates that these ecosystem services often depend on complex relationships between communities of microorganisms (the 'microbiome') and the environment or their hosts - termed the 'holobiont'. Understanding of coastal ecosystem function must therefore be framed under the holobiont concept, whereby macroorganisms and their associated microbiomes are considered as a synergistic ecological unit. Here, we evaluate the current state of knowledge on coastal marine microbiome research and identify key questions within this growing research area. Although the list of questions is broad and ambitious, progress in the field is increasing exponentially, and the emergence of large, international collaborative networks and well-executed manipulative experiments are rapidly advancing the field of coastal marine microbiome research.

Fencing farm dams to exclude livestock halves methane emissions and improves water quality.

Publisher: California Digital Library (CDL)

Date: 18-05-2022

DOI: 10.31223/X5193Z

Abstract: Agricultural practices have created tens of millions of small artificial water bodies (“farm dams” or “agricultural ponds”) to provide water for domestic livestock worldwide. Among freshwater ecosystems, farm dams have some of the highest greenhouse gas (GHG) emissions per m2 due to fertilizer and manure run-off boosting methane production – an extremely potent GHG. However, management strategies to mitigate the substantial emissions from millions of farm dams remain unexplored. We tested the hypothesis that installing fences to exclude livestock could reduce nutrients, improve water quality, and lower aquatic GHG emissions. We established a large-scale experiment spanning 400 km across south-eastern Australia where we compared unfenced (N = 33) and fenced farm dams (N = 31) within 17 livestock farms. Fenced farm dams recorded 32% less dissolved nitrogen, 39% less dissolved phosphorus, 22% more dissolved oxygen, and produced 56% less diffusive methane emissions than unfenced dams. We found no effect of farm dam management on diffusive carbon dioxide emissions and on the organic carbon in the soil. Dissolved oxygen was the most important variable explaining changes in carbon fluxes across dams, whereby doubling dissolved oxygen from 5 to 10 mg L-1 led to a 74% decrease in methane fluxes, a 124% decrease in carbon dioxide fluxes, and a 96% decrease in CO2-eq (CH4 + CO2) fluxes. Dams with very high dissolved oxygen ( mg L-1) showed a switch from positive to negative CO2-eq. (CO2 + CH4) fluxes (i.e., negative radiative balance), indicating a positive contribution to reduce atmospheric warming. Our results demonstrate that simple management actions can dramatically improve water quality and decrease methane emissions while contributing to more productive and sustainable farming.

Eyes in the sea: Unlocking the mysteries of the ocean using industrial, remotely operated vehicles (ROVs)

Publisher: Elsevier BV

Date: 09-2018

DOI: 10.1016/J.SCITOTENV.2018.04.049

Abstract: For thousands of years humankind has sought to explore our oceans. Evidence of this early intrigue dates back to 130,000BCE, but the advent of remotely operated vehicles (ROVs) in the 1950s introduced technology that has had significant impact on ocean exploration. Today, ROVs play a critical role in both military (e.g. retrieving torpedoes and mines) and salvage operations (e.g. locating historic shipwrecks such as the RMS Titanic), and are crucial for oil and gas (O&G) exploration and operations. Industrial ROVs collect millions of observations of our oceans each year, fueling scientific discoveries. Herein, we assembled a group of international ROV experts from both academia and industry to reflect on these discoveries and, more importantly, to identify key questions relating to our oceans that can be supported using industry ROVs. From a long list, we narrowed down to the 10 most important questions in ocean science that we feel can be supported (whole or in part) by increasing access to industry ROVs, and collaborations with the companies that use them. The questions covered opportunity (e.g. what is the resource value of the oceans?) to the impacts of global change (e.g. which marine ecosystems are most sensitive to anthropogenic impact?). Looking ahead, we provide recommendations for how data collected by ROVs can be maximised by higher levels of collaboration between academia and industry, resulting in win-win outcomes. What is clear from this work is that the potential of industrial ROV technology in unravelling the mysteries of our oceans is only just beginning to be realised. This is particularly important as the oceans are subject to increasing impacts from global change and industrial exploitation. The coming decades will represent an important time for scientists to partner with industry that use ROVs in order to make the most of these 'eyes in the sea'.

Converting beach-cast seagrass wrack into biochar: A climate-friendly solution to a coastal problem

Publisher: Elsevier BV

Date: 2017

DOI: 10.1016/J.SCITOTENV.2016.09.021

Abstract: Excessive accumulation of plant 'wrack' on beaches as a result of coastal development and beach modification (e.g. groin installation) is a global problem. This study investigated the potential for converting beach-cast seagrass wrack into biochar as a 'climate-friendly' disposal option for resource managers. Wrack s les from 11 seagrass species around Australia were initially screened for their biochar potential using pyrolysis techniques, and then two species - Posidonia australis and Zostera muelleri - underwent detailed analyses. Both species had high levels of refractory materials and high conversion efficiency (48-57%) of plant carbon into biochar carbon, which is comparable to high-quality terrestrial biochar products. P. australis wrack gave higher biochar yields than Z. muelleri consistent with its higher initial carbon content. According to

Planted mangroves cap toxic oil spill

Publisher: California Digital Library (CDL)

Date: 07-12-2020

DOI: 10.31223/X5NP53

Addressing calcium carbonate cycling in blue carbon accounting

Publisher: Wiley

Date: 24-10-2017

DOI: 10.1002/LOL2.10052

Deakin University

Location: Australia

View Organisation

Discovery Projects - Grant ID: DP200100575

Start Date: 06-2020

End Date: 12-2024

Amount: $559,850.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP160100061

Start Date: 12-2016

End Date: 12-2020

Amount: $401,000.00

Funder: Australian Research Council

Discovery Early Career Researcher Award - Grant ID: DE130101084

Start Date: 2013

End Date: 01-2016

Amount: $375,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP160100242

Start Date: 12-2016

End Date: 12-2020

Amount: $326,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP160100492

Start Date: 12-2016

End Date: 12-2020

Amount: $490,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE170100219

Start Date: 2017

End Date: 12-2017

Amount: $170,000.00

Funder: Australian Research Council