ORCID Profile
0000-0001-5162-273X
Current Organisation
Edith Cowan University
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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)
Isotope Geochemistry | Environmental Science and Management | Ecological Impacts of Climate Change | Palaeoclimatology | Ecology | Geochemistry | Ecological Applications | Biological Oceanography | Chemical Oceanography | Organic Geochemistry | Geochronology | Marine and Estuarine Ecology (incl. Marine Ichthyology) | Terrestrial Ecology | Functional Materials | Ecosystem Function | Environmental Chemistry (incl. Atmospheric Chemistry) | Conservation and Biodiversity | Marine And Estuarine Ecology (Incl. Marine Ichthyology) | Environmental Monitoring | Conservation And Biodiversity | Ecological Physiology | Freshwater Ecology
ANZSRC Socio-Economic Objective (SEO)
Marine protected areas | Estuarine and lagoon areas | Climate variability | Climate change | Living resources (incl. impacts of fishing on non-target species) | Integrated (ecosystem) assessment and management | Ecosystem Adaptation to Climate Change | Ecosystem Assessment and Management of Fresh, Ground and Surface Water Environments | Land and water management | Mineral Exploration not elsewhere classified | Integrated (ecosystem) assessment and management | Oil and Gas Exploration | Physical and chemical conditions | Living resources (flora and fauna) | Land and water management | Solid Oxide Fuel Cells | Oceanic processes (excl. climate related) | Ecosystem Assessment and Management of Marine Environments |
Related Links
Publications
Size, not morphology, determines hydrodynamic performance of a kelp during peak flow
Publisher: Springer Science and Business Media LLC
Date: 15-12-2012
Seagrass meadows as a globally significant carbonate reservoir
Publisher: Copernicus GmbH
Date: 24-08-2015
Abstract: Abstract. There has been growing interest in quantifying the capacity of seagrass ecosystems to act as carbon sinks as a natural way of offsetting anthropogenic carbon emissions to the atmosphere. However, most of the efforts have focused on the particulate organic carbon (POC) stocks and accumulation rates and ignored the particulate inorganic carbon (PIC) fraction, despite important carbonate pools associated with calcifying organisms inhabiting the meadows, such as epiphytes and benthic invertebrates, and despite the relevance that carbonate precipitation and dissolution processes have in the global carbon cycle. This study offers the first assessment of the global PIC stocks in seagrass sediments using a synthesis of published and unpublished data on sediment carbonate concentration from 403 vegetated and 34 adjacent un-vegetated sites. PIC stocks in the top 1 m of sediment ranged between 3 and 1660 Mg PIC ha−1, with an average of 654 ± 24 Mg PIC ha−1, exceeding those of POC reported in previous studies by about a factor of 5. Sedimentary carbonate stocks varied across seagrass communities, with meadows dominated by Halodule, Thalassia or Cymodocea supporting the highest PIC stocks, and tended to decrease polewards at a rate of −8 ± 2 Mg PIC ha−1 per degree of latitude (general linear model, GLM p 0.0003). Using PIC concentrations and estimates of sediment accretion in seagrass meadows, the mean PIC accumulation rate in seagrass sediments is found to be 126.3 ± 31.05 g PIC m−2 yr−1. Based on the global extent of seagrass meadows (177 000 to 600 000 km2), these ecosystems globally store between 11 and 39 Pg of PIC in the top metre of sediment and accumulate between 22 and 75 Tg PIC yr−1, representing a significant contribution to the carbonate dynamics of coastal areas. Despite the fact that these high rates of carbonate accumulation imply CO2 emissions from precipitation, seagrass meadows are still strong CO2 sinks as demonstrated by the comparison of carbon (PIC and POC) stocks between vegetated and adjacent un-vegetated sediments.
Seagrass losses since mid‐20th century fuelled CO2 emissions from soil carbon stocks
Publisher: Wiley
Date: 07-07-2020
DOI: 10.1111/GCB.15204
The Central Role of Dispersal in the Maintenance and Persistence of Seagrass Populations
Publisher: Oxford University Press (OUP)
Date: 10-2019
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.
Soil Carbon Stocks Vary Across Geomorphic Settings in Australian Temperate Tidal Marsh Ecosystems
Publisher: Springer Science and Business Media LLC
Date: 24-06-2020
DOI: 10.1007/S10021-020-00520-9
Abstract: Tidal marshes rank among the ecosystems with the highest capacity to sequester and store organic carbon (C org ) on earth. To inform conservation of coastal vegetated ecosystems for climate change mitigation, this study investigated the factors driving variability in carbon storage. We estimated soil C org stocks in tidal marshes across temperate Western Australia and assessed differences among geomorphic settings (marine and fluvial deltas, and mid-estuary) and vegetation type ( Sarcocornia quinqueflora and Juncus kraussii ) linked to soil biogeochemistry. Soil C org stocks within fluvial and mid-estuary settings were significantly higher (209 ± 14 and 211 ± 20 Mg C org ha −1 , respectively 1-m-thick soils) than in marine counterparts (156 ± 12 Mg C org ha −1 ), which can be partially explained by higher preservation of soil C org in fluvial and mid-estuary settings rich in fine-grained ( 0.063 mm) sediments (49 ± 3% and 47 ± 4%, respectively) compared to marine settings (23 ± 4%). Soil C org stocks were not significantly different between S. quinqueflora and J. kraussii marshes (185 ± 13 and 202 ± 13 Mg C org ha −1 , respectively). The higher contribution of tidal marsh plus supratidal vegetation in fluvial (80%) and intermediate (76%) compared to marine (57%) settings further explains differences in soil C org stocks. The estimated soil C org stocks in temperate Western Australia’s tidal marshes (57 Tg C org within ~ 3000 km 2 extent) correspond to about 2% of worldwide tidal marsh soil C org stocks. The results obtained identify global drivers of soil C org storage in tidal marshes and can be used to target hot spots for climate change mitigation based on tidal marsh conservation.
Determining light stress responses for a tropical multi-species seagrass assemblage
Publisher: Elsevier BV
Date: 03-2018
DOI: 10.1016/J.MARPOLBUL.2018.01.060
Abstract: Existing mitigations to address deterioration in water clarity associated with human activities are based on responses from single seagrass species but may not be appropriate for erse seagrass assemblages common to tropical waters. We present findings from a light experiment designed to determine the effects of magnitude and duration of low light on a mixed tropical seagrass assemblage. Mixed assemblages of three commonly co-occurring Indo-West Pacific seagrasses, Cymodocea serrulata, Halodule uninervis and Halophila ovalis were grown in climate-controlled tanks, where replicate pots were subjected to a gradient in light availability (0.9-21.6 mols PAR m
Historical processes and contemporary ocean currents drive genetic structure in the seagrass T halassia hemprichii in the Indo‐Australian Archipelago
Publisher: Wiley
Date: 02-2017
DOI: 10.1111/MEC.13966
Abstract: Understanding spatial patterns of gene flow and genetic structure is essential for the conservation of marine ecosystems. Contemporary ocean currents and historical isolation due to Pleistocene sea level fluctuations have been predicted to influence the genetic structure in marine populations. In the Indo-Australian Archipelago (IAA), the world's hotspot of marine bio ersity, seagrasses are a vital component but population genetic information is very limited. Here, we reconstructed the phylogeography of the seagrass Thalassia hemprichii in the IAA based on single nucleotide polymorphisms (SNPs) and then characterized the genetic structure based on a panel of 16 microsatellite markers. We further examined the relative importance of historical isolation and contemporary ocean currents in driving the patterns of genetic structure. Results from SNPs revealed three population groups: eastern Indonesia, western Indonesia (Sunda Shelf) and Indian Ocean while the microsatellites supported five population groups (eastern Indonesia, Sunda Shelf, Lesser Sunda, Western Australia and Indian Ocean). Both SNPs and microsatellites showed asymmetrical gene flow among population groups with a trend of southwestward migration from eastern Indonesia. Genetic ersity was generally higher in eastern Indonesia and decreased southwestward. The pattern of genetic structure and connectivity is attributed partly to the Pleistocene sea level fluctuations modified to a smaller level by contemporary ocean currents.
Vertical mixing in coastal canopies
Publisher: Wiley
Date: 29-09-2016
DOI: 10.1002/LNO.10368
Role of carbonate burial in Blue Carbon budgets
Publisher: Springer Science and Business Media LLC
Date: 07-03-2019
DOI: 10.1038/S41467-019-08842-6
Abstract: Calcium carbonates (CaCO 3 ) often accumulate in mangrove and seagrass sediments. As CaCO 3 production emits CO 2 , there is concern that this may partially offset the role of Blue Carbon ecosystems as CO 2 sinks through the burial of organic carbon (C org ). A global collection of data on inorganic carbon burial rates (C inorg , 12% of CaCO 3 mass) revealed global rates of 0.8 TgC inorg yr −1 and 15–62 TgC inorg yr −1 in mangrove and seagrass ecosystems, respectively. In seagrass, CaCO 3 burial may correspond to an offset of 30% of the net CO 2 sequestration. However, a mass balance assessment highlights that the C inorg burial is mainly supported by inputs from adjacent ecosystems rather than by local calcification, and that Blue Carbon ecosystems are sites of net CaCO 3 dissolution. Hence, CaCO 3 burial in Blue Carbon ecosystems contribute to seabed elevation and therefore buffers sea-level rise, without undermining their role as CO 2 sinks.
Should we sync? Seascape‐level genetic and ecological factors determine seagrass flowering patterns
Publisher: Wiley
Date: 24-09-2015
Release of dissolved organic carbon from seagrass wrack and its implications for trophic connectivity
Publisher: Inter-Research Science Center
Date: 04-12-2013
DOI: 10.3354/MEPS10554
Phenological decoupling of mortality from wave forcing in kelp beds
Publisher: Wiley
Date: 03-2015
DOI: 10.1890/13-2365.1
Abstract: Kelps often live in a harsh hydrodynamic environment where wave-driven dislodgement of in iduals can alter the bio ersity and functioning of reef systems, and increase production in coastal ecosystems adjacent to reefs. The current paradigm is that winter storms tear kelps from reefs once hydrodynamic forces exceed attachment or tissue strength--a threshold response that implies a pulsed relationship between wave forces and dislodgement. Here, we challenge this understanding by showing how kelp phenology can decouple susceptibility to dislodgement from seasonal patterns in wave forces. We measured kelp dislodgement rates and hydrodynamic forces at nine subtidal reefs over two years (n = 4320 kelps tagged and monitored). Contrary to expectation, we found relatively low and constant dislodgement rates for all reefs (13% +/- 6% [mean per season +/- SD]) in spite of a strong temporal pattern in wave action and extreme water velocities (winter peaks up to 3-4 m/s). A biomechanical model, based on the balance between kelp attachment strength and hydrodynamic drag, demonstrated that severe reduction in in idual kelp size toward winter (>50% decrease in biomass for all sites) minimized drag and made the kelps less susceptible to high water velocities, allowing in iduals to survive storm velocities over 3-4 m/s. We conclude that the timing of reduced susceptibility to disturbance, through the seasonal reduction of in idual kelp biomass that coincides with times of highest water velocities is critical to the dynamics of kelp dislodgement and survival. We propose that phenological processes maintain many kelp beds in a higher degree of population stability and equilibrium with hydrodynamic forces than previously believed.
Accelerating Tropicalization and the Transformation of Temperate Seagrass Meadows
Publisher: Oxford University Press (OUP)
Date: 14-09-2016
Supplementary material to "Seagrass meadows as a globally significant carbonate reservoir"
Publisher: Copernicus GmbH
Date: 06-03-2015
The use of Fick's First Law for predicting porewater nutrient fluxes under diffusive conditions
Publisher: Wiley
Date: 09-2001
DOI: 10.1002/HYP.297
Modeling Organic Carbon Accumulation Rates and Residence Times in Coastal Vegetated Ecosystems
Publisher: American Geophysical Union (AGU)
Date: 11-2019
DOI: 10.1029/2019JG005233
Utilization of carbon substrates by heterotrophic bacteria through vertical sediment profiles in coastal and estuarine seagrass meadows
Publisher: Wiley
Date: 18-05-2016
Abstract: Coastal vegetated ecosystems play an important role in carbon cycling and bacterial communities inhabiting coastal sediments are responsible for the remineralization and processing of organic carbon (OC). We collected 1 m-long sediment cores in Posidonia seagrass meadows from coastal and estuarine sites in Australia that differed in their sedimentary organic and inorganic carbon, nitrogen and mud contents. The metabolic ersity of sediment heterotrophic bacterial communities was characterized at different sediment depths, based on the utilization pattern of 31 in idual carbon substrates using Biolog EcoPlates
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.
Trophic implications and faunal resilience following one-off and successive disturbances to an Amphibolis griffithii seagrass system
Publisher: Elsevier BV
Date: 05-2015
DOI: 10.1016/J.MARPOLBUL.2015.03.001
Abstract: Disturbances in seagrass systems often lead to considerable loss of seagrass fauna. We examined the capacity for seagrass fauna, across multiple trophic levels, to recover from disturbances, using empirical and modelling techniques. Model outputs, using Ecosim with Ecopath (EwE), were consistent with the results of field investigations, highlighting the models robustness. Modelled outcomes suggest second and third order consumers are likely to be negatively effected by disturbances in the seagrass canopy. Particularly piscivores, which once disturbed, appear unlikely to recover following severe declines in primary productivity. EwE also revealed the complex interaction between the duration and intensity of disturbances on seagrass fauna, which may differentially affect higher order consumers. Further, modelling predicted a variable capacity of higher order consumers to recover from successive disturbances, suggesting taxa with comparatively fast reproductive cycles and short generation terms would be more resilient than taxa with comparatively long generation terms and slow reproductive cycles.
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
Spatial variation in the signature of Ruppia megacarpa (Mason) in coastal lagoons of southwestern Australia and its implication for isotopic studies
Publisher: Elsevier BV
Date: 10-2001
Use of d15N signatures of different functional forms of macroalgae and filter-feeders to reveal temporal and spatial patterns in sewage dispersal
Publisher: Inter-Research Science Center
Date: 2002
DOI: 10.3354/MEPS235063
Faster R-CNN Based Deep Learning for Seagrass Detection from Underwater Digital Images
Publisher: IEEE
Date: 12-2019
Filtering capacity of seagrass meadows and other habitats of Cockburn Sound, Western Australia
Publisher: Inter-Research Science Center
Date: 1996
DOI: 10.3354/MEPS143187
Intensity of herbivory on kelp by fish and sea urchins differs between inshore and offshore reefs
Publisher: Inter-Research Science Center
Date: 11-02-2009
DOI: 10.3354/MEPS07811
Carbon and nitrogen translocation in response to shading of the seagrass Posidonia sinuosa
Publisher: Elsevier BV
Date: 07-2010
Estimates of water quality in coastal waters using multi-date Landsat Thematic Mapper data
Publisher: Informa UK Limited
Date: 20-05-1994
Disturbance Is an Important Driver of Clonal Richness in Tropical Seagrasses
Publisher: Frontiers Media SA
Date: 05-12-2017
Influence of water depth on the carbon sequestration capacity of seagrasses
Publisher: American Geophysical Union (AGU)
Date: 09-2014
DOI: 10.1002/2014GB004872
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.
Contrasting mechanisms of dislodgement and erosion contribute to production of kelp detritus
Publisher: Wiley
Date: 27-08-2013
Ecological significance of seagrasses: Assessment for management of environmental impact in Western Australia
Publisher: Elsevier BV
Date: 2001
Does transported seagrass provide an important trophic link in unvegetated, nearshore areas?
Publisher: Elsevier BV
Date: 06-2005
Seagrass Meadows Provide 3D Habitat for Reef Fish
Publisher: Frontiers Media SA
Date: 28-02-2017
Spatial and temporal patterns in the distribution of large bivalves in a permanently open temperate estuary: implications for management
Publisher: CSIRO Publishing
Date: 2015
DOI: 10.1071/MF13209
Abstract: To inform management, baseline ecological studies in estuaries must be implemented at spatial scales that accommodate both environmental gradients and likely anthropogenic pressures. We describe fine-scale spatial patterns in the abundances and size structure of large infaunal bivalves inhabiting shallow sand habitats in the lower reaches of a relatively undisturbed, permanently open, temperate estuary. S ling over 3 years at 19 sites during the autumn, when freshwater influence was minimal, revealed that Soletellina alba, Wallucina assimilis and Paphies elongata were consistently the most abundant of nine species present. Although most abundant near the ocean entrance, S. alba was distributed widely and shells of differing lengths, and presumably ages, were present at most sites, suggesting that this species recruited continuously throughout the study area when conditions were appropriate. In contrast, W. assimilis and P. elongata occurred only near or in the entrance channel of the Nornalup Inlet in areas where seagrass rhizomes may grow and where oceanic influences caused relatively turbulent conditions, respectively. Sediment structure appeared to exert only a moderate and intermittent influence on the bivalve assemblage at some sites where particularly large grain sizes occurred. This study provides important baseline information on the distribution and abundance of large bivalves in this estuary. These species are likely to be important in the trophic ecology of this system and are potential indicators of disturbance and ecosystem health.
Deep learning on underwater marine object detection: A survey
Publisher: Springer International Publishing
Date: 2017
Identifying robust bioindicators of light stress in seagrasses: A meta-analysis
Publisher: Elsevier BV
Date: 07-2013
13C and 15N translocation within and among shoots in two Posidonia species from Western Australia
Publisher: Inter-Research Science Center
Date: 09-06-2008
DOI: 10.3354/MEPS07405
A comparison of hole punch and needle punch methods for the measurement of seagrass productivity
Publisher: Elsevier BV
Date: 10-2006
Identifying knowledge gaps in seagrass research and management: An Australian perspective
Publisher: Elsevier BV
Date: 06-2017
DOI: 10.1016/J.MARENVRES.2016.06.006
Abstract: Seagrass species form important marine and estuarine habitats providing valuable ecosystem services and functions. Coastal zones that are increasingly impacted by anthropogenic development have experienced substantial declines in seagrass abundance around the world. Australia, which has some of the world's largest seagrass meadows and is home to over half of the known species, is not immune to these losses. In 1999 a review of seagrass ecosystems knowledge was conducted in Australia and strategic research priorities were developed to provide research direction for future studies and management. Subsequent rapid evolution of seagrass research and scientific methods has led to more than 70% of peer reviewed seagrass literature being produced since that time. A workshop was held as part of the Australian Marine Sciences Association conference in July 2015 in Geelong, Victoria, to update and redefine strategic priorities in seagrass research. Participants identified 40 research questions from 10 research fields (taxonomy and systematics, physiology, population biology, sediment biogeochemistry and microbiology, ecosystem function, faunal habitats, threats, rehabilitation and restoration, mapping and monitoring, management tools) as priorities for future research on Australian seagrasses. Progress in research will rely on advances in areas such as remote sensing, genomic tools, microsensors, computer modeling, and statistical analyses. A more interdisciplinary approach will be needed to facilitate greater understanding of the complex interactions among seagrasses and their environment.
Sequestration of macroalgal carbon: the elephant in the Blue Carbon room
Publisher: The Royal Society
Date: 06-2018
Abstract: Macroalgae form the most extensive and productive benthic marine vegetated habitats globally but their inclusion in Blue Carbon (BC) strategies remains controversial. We review the arguments offered to reject or include macroalgae in the BC framework, and identify the challenges that have precluded macroalgae from being incorporated so far. Evidence that macroalgae support significant carbon burial is compelling. The carbon they supply to sediment stocks in angiosperm BC habitats is already included in current assessments, so that macroalgae are de facto recognized as important donors of BC. The key challenges are (i) documenting macroalgal carbon sequestered beyond BC habitat, (ii) tracing it back to source habitats, and (iii) showing that management actions at the habitat lead to increased sequestration at the sink site. These challenges apply equally to carbon exported from BC coastal habitats. Because of the large carbon sink they support, incorporation of macroalgae into BC accounting and actions is an imperative. This requires a paradigm shift in accounting procedures as well as developing methods to enable the capacity to trace carbon from donor to sink habitats in the ocean.
Food web analysis in two permanently open temperate estuaries: Consequences of saltmarsh loss?
Publisher: Elsevier BV
Date: 09-2007
DOI: 10.1016/J.MARENVRES.2007.02.002
Abstract: Saltmarsh vegetation, seston and microphytobenthos are all conspicuous components of most temperate estuaries and they potentially contribute to the estuarine food chain. Yet their relative contributions are unclear, as is the significance of saltmarsh losses through natural and human-induced impacts. This study aimed to quantitatively determine the contribution of various types of primary producers to detritus in the Walpole-Nornalup Estuary and Leschenault Inlet, two permanently open estuaries in SW Australia, and, estimate the flow of different types of detritus to higher trophic levels, using carbon ((13)C) and nitrogen ((15)N) stable isotopes as tracers. Results of the mixing model indicated that seston, microphytobenthos and to some extent seagrass and fringing saltmarsh were the main contributors to the detrital pool in both estuaries. However, the relative contribution of different primary producers varied both within and between estuaries. The contribution of saltmarsh was higher at sites close to rivers and dense fringing vegetation, while seston, microphytobenthos and seagrass dominated the detrital material at other sites. Benthic harpacticoid copepods were shown to feed on detritus though they appeared to actively select for different components of the detritus depending on site and estuary. Isotopic signatures of other consumers indicated that fish and invertebrates derived nutrients from MPB and detritus, either directly as food or indirectly through feeding on invertebrates. The overall contribution of saltmarsh to detritus was lower in Leschenault Inlet than in Walpole-Nornalup Estuary, possibly as a result of increased clearing of fringing vegetation around Leschenault Inlet. This pattern was however not reflected in harpacticoid food. Therefore, although losses of fringing saltmarsh around estuaries have the potential to significantly affect estuarine food webs, the significance of such losses will be site- and estuary-dependent.
Reviews and syntheses: <sup>210</sup>Pb-derived sediment and carbon accumulation rates in vegetated coastal ecosystems – setting the record straight
Publisher: Copernicus GmbH
Date: 15-11-2018
Abstract: Abstract. Vegetated coastal ecosystems, including tidal marshes, mangroves and seagrass meadows, are being increasingly assessed in terms of their potential for carbon dioxide sequestration worldwide. However, there is a paucity of studies that have effectively estimated the accumulation rates of sediment organic carbon (Corg), also termed blue carbon, beyond the mere quantification of Corg stocks. Here, we discuss the use of the 210Pb dating technique to determine the rate of Corg accumulation in these habitats. We review the most widely used 210Pb dating models to assess their limitations in these ecosystems, often composed of heterogeneous sediments with varying inputs of organic material, that are disturbed by natural and anthropogenic processes resulting in sediment mixing and changes in sedimentation rates or erosion. Through a range of simulations, we consider the most relevant processes that impact the 210Pb records in vegetated coastal ecosystems and evaluate how anomalies in 210Pb specific activity profiles affect sediment and Corg accumulation rates. Our results show that the discrepancy in sediment and derived Corg accumulation rates between anomalous and ideal 210Pb profiles is within 20 % if the process causing such anomalies is well understood. While these discrepancies might be acceptable for the determination of mean sediment and Corg accumulation rates over the last century, they may not always provide a reliable geochronology or historical reconstruction. Reliable estimates of Corg accumulation rates might be difficult at sites with slow sedimentation, intense mixing and/or that are affected by multiple sedimentary processes. Additional tracers or geochemical, ecological or historical data need to be used to validate the 210Pb-derived results. The framework provided in this study can be instrumental in reducing the uncertainties associated with estimates of Corg accumulation rates in vegetated coastal sediments.
Habitat characteristics provide insights of carbon storage in seagrass meadows
Publisher: Elsevier BV
Date: 09-2018
DOI: 10.1016/J.MARPOLBUL.2018.01.059
Abstract: Seagrass meadows provide multiple ecosystem services, yet they are among the most threatened ecosystems on earth. Because of their role as carbon sinks, protection and restoration of seagrass meadows contribute to climate change mitigation. Blue Carbon strategies aim to enhance CO
Automatic seagrass detection: A survey
Publisher: IEEE
Date: 11-2017
Marine macrophytes directly enhance abundances of sandy beach fauna through provision of food and habitat
Publisher: Elsevier BV
Date: 08-2007
An efficient method for collecting large samples of live copepods free from detritus
Publisher: CSIRO Publishing
Date: 2010
DOI: 10.1071/MF09178
Abstract: Meiofauna are often important in the transfer of organic material to higher trophic levels in aquatic environments. However, in food web analysis the group is frequently pooled or ignored owing to the difficulty in isolating in idual components of the assemblage. In this study, we developed and tested a new method for extracting photopositive and detritus-free copepod s les from sediments, and compared this method to a previous technique (Couch 1989). In our initial trials, ∼400 copepods (all orders included) were collected in 15 min compared with 60 copepods using Couch’s method. In subsequent trials that focussed on specific orders of copepods, our method was at least 10 times more efficient than Couch’s method at collecting cyclopoid and harpacticoid copepods from sediments. The new method requires very little supervision and there is no requirement for a particular intensity of light. This method can increase the collection of large numbers of photopositive copepods in aquatic systems, and thereby facilitate the inclusion of this important component into future food web studies, particularly those using biomarkers such as stable isotopes or fatty acids.
Ecological Effects of Macroalgal Harvesting on Beaches in the Peel-Harvey Estuary, Western Australia
Publisher: Elsevier BV
Date: 04-2003
Reefs as contributors to diversity of epiphytic macroalgae assemblages in seagrass meadows
Publisher: Inter-Research Science Center
Date: 2004
DOI: 10.3354/MEPS276071
Complex hybridity in Isotoma petraea. VI. Distorted segregation, gametic lethal systems and population divergence
Publisher: Springer Science and Business Media LLC
Date: 06-1987
DOI: 10.1038/HDY.1987.68
A comparison of spatial and temporal patterns in epiphytic macroalgal assemblages of the seagrasses Amphibolis griffithii and Posidonia coriacea
Publisher: Inter-Research Science Center
Date: 2002
DOI: 10.3354/MEPS236099
Factors Determining Seagrass Blue Carbon Across Bioregions and Geomorphologies
Publisher: American Geophysical Union (AGU)
Date: 06-2021
DOI: 10.1029/2021GB006935
Abstract: Seagrass meadows rank among the most significant organic carbon (C org ) sinks on earth. We examined the variability in seagrass soil C org stocks and composition across Australia and identified the main drivers of variability, applying a spatially hierarchical approach that incorporates bioregions and geomorphic settings. Top 30 cm soil C org stocks were similar across bioregions and geomorphic settings (min‐max: 20–26 Mg C org ha −1 ), but meadows formed by large species (i.e., Amphibolis spp. and Posidonia spp.) showed higher stocks (24–29 Mg C org ha −1 ) than those formed by smaller species (e.g., Halodule, Halophila, Ruppia, Zostera, Cymodocea, and Syringodium 12–21 Mg C org ha −1 ). In temperate coastal meadows dominated by large species, soil C org stocks mainly derived from seagrass C org (72 ± 2%), while allochthonous C org dominated soil C org stocks in meadows formed by small species in temperate and tropical estuarine meadows (64 ± 5%). In temperate coastal meadows, soil C org stocks were enhanced by low hydrodynamic exposure associated with high mud and seagrass C org contents. In temperate estuarine meadows, soil C org stocks were enhanced by high contributions of seagrass C org , low to moderate solar radiation, and low human pressure. In tropical estuarine meadows formed by small species, large soil C org stocks were mainly associated with low hydrodynamic energy, low rainfall, and high solar radiation. These results showcase that bioregion and geomorphic setting are not necessarily good predictors of soil C org stocks and that site‐specific estimates based on local environmental factors are needed for Blue Carbon projects and greenhouse gases accounting purposes.
Assessing the risk of carbon dioxide emissions from blue carbon ecosystems
Publisher: Wiley
Date: 15-05-2017
DOI: 10.1002/FEE.1491
Long-term carbon storage and its recent loss in an estuarine Posidonia australis meadow (Albany, Western Australia)
Publisher: Elsevier BV
Date: 03-2016
Key biogeochemical factors affecting soil carbon storage in <i>Posidonia</i> meadows
Publisher: Copernicus GmbH
Date: 27-11-2015
DOI: 10.5194/BGD-12-18913-2015
Abstract: Abstract. Biotic and abiotic factors influence the accumulation of organic carbon (Corg) in seagrass ecosystems. We surveyed Posidonia sinuosa meadows growing in different water depths to assess the variability in the sources, stocks and accumulation rates of Corg. We show that over the last 500 years, P. sinuosa meadows closer to the upper limit of distribution (at 2–4 m depth) accumulated 3 to 4-fold higher Corg stocks (averaging 6.3 kg Corg m−2) at 3 to 4-fold higher rates (12.8 g Corg m−2 yr−1) compared to meadows closer to the deep limits of distribution (at 6–8 m depth 1.8 kg Corg m−2 and 3.6 g Corg m−2 yr−1). In shallower meadows, Corg stores were mostly derived from seagrass detritus (88 % in average) compared to meadows closer to the deep limit of distribution (45 % on average). Also, sediment accumulation rates and fine-grained sediment content ( 0.125 mm) in shallower meadows (2.0 mm yr−1 and 9 %, respectively) were approximately 2-fold higher than in deeper meadows (1.2 mm yr−1 and 5 %, respectively). The Corg stocks and accumulation rates accumulated over the last 500 years in bare sediments (0.6 kg Corg m−2 and 1.2 g Corg m−2 yr−1) were 3 to 11-fold lower than in P. sinuosa meadows, while fine-grained sediment content (1 %) and seagrass detritus contribution to the Corg pool (20 %) were 8 and 3-fold lower than in Posidonia meadows, respectively. The patterns found support the hypotheses that Corg storage in seagrass soils is influenced by interactions of biological (e.g. meadow productivity, cover and density), chemical (e.g. recalcitrance of Corg stocks) and physical (e.g. hydrodynamic energy and sediment accumulation rates) factors within the meadow. We conclude that there is a need to improve global estimates of seagrass carbon storage accounting for biogeochemical factors driving variability within habitats.
A marine heatwave drives massive losses from the world’s largest seagrass carbon stocks
Publisher: Springer Science and Business Media LLC
Date: 19-03-2018
The impact of flexibility on flow, turbulence, and vertical mixing in coastal canopies
Publisher: Wiley
Date: 06-08-2018
DOI: 10.1002/LNO.11008
Correction: Global patterns in mangrove soil carbon stocks and losses (Nature Climate Change (2017) DOI: 10.1038/nclimate3326)
Publisher: Springer Science and Business Media LLC
Date: 27-11-2018
Effect of leaf movement on epiphytic algal biomass of seagrass leaves
Publisher: Inter-Research Science Center
Date: 24-05-2007
DOI: 10.3354/MEPS338097
Changes in the biomass and species composition of macroalgae in a eutrophic estuary
Publisher: Elsevier BV
Date: 07-1991
Effects of multiple disturbances in seagrass meadows: shading decreases resilience to grazing
Publisher: CSIRO Publishing
Date: 2009
DOI: 10.1071/MF09008
Abstract: Ecosystem shifts are often associated with multiple disturbances, but limited knowledge on the mechanisms involved h ers management. This study investigated how short-term shading affected the resilience of the seagrass Halophila ovalis to grazing by black swans (Cygnus atratus) – a historically dominant grazer currently recovering from hunting and habitat loss – in south-western Australian estuaries, using field surveys and a grazing-shading experiment. Black swans were heterogeneously distributed and, in a high-density site, consumed 23% of seagrass production. Seagrasses recovered rapidly from a single disturbance (i.e. short-term shading or grazing), even though shading alone halved carbohydrate content. When seagrasses were exposed to both disturbances, recovery depended on the type of grazing where grazing was confined to leaves, leaf densities recovered within 3 weeks, but where grazing was on both leaves and rhizomes there was no recovery. Shading increased the frequency of apex initiation, as did rhizome grazing, but only if the plants had not been shaded. This indicates that shading alters the flow of energy needed to produce apices and leaves following disturbance on rhizomes. Based on the historical swan densities and continuing recurring phytoplankton blooms, management actions reintroducing swans without controlling algal blooms could have an on impact seagrass resilience and associated organisms.
Global patterns in mangrove soil carbon stocks and losses
Publisher: Springer Science and Business Media LLC
Date: 26-06-2017
DOI: 10.1038/NCLIMATE3326
Dual processes for cross-boundary subsidies: incorporation of nutrients from reef-derived kelp into a seagrass ecosystem
Publisher: Inter-Research Science Center
Date: 20-01-2012
DOI: 10.3354/MEPS09367
Reviews and syntheses: <sup>210</sup>Pb-derived sediment and carbon accumulation rates in vegetated coastal ecosystems: setting the record straight
Publisher: Copernicus GmbH
Date: 10-04-2018
DOI: 10.5194/BG-2018-78
Abstract: Abstract. Vegetated coastal ecosystems, including tidal marsh, mangrove and seagrass, are being increasingly assessed for their potential in carbon dioxide sequestration worldwide. However, there is a paucity of studies that have effectively estimated the accumulation rates of sediment organic carbon (Corg) beyond the mere quantification of Corg stocks. Here, we discuss the use of the 210Pb dating technique as a practical tool to measure the rate of Corg accumulation in vegetated coastal ecosystems. We critically review the status of 210Pb dating methods of vegetated coastal sediments and assess the limitations that apply to these ecosystems, which are often composed by heterogeneous sediments, abundant in coarse particles, with varying inputs of organic material, and are disturbed by natural and anthropogenic processes causing sediment mixing, changes in sedimentation rates or erosion. Through a range of simulations, we discuss the most relevant processes that impact the 210Pb record in vegetated coastal ecosystems and evaluate the deviations in sediment and Corg accumulation rates produced by anomalies in 210Pb profiles. Our results show that the deviation in the determination of sediment and derived Corg accumulation rates is within 20 % confirming that the 210Pb dating technique is secure. However, while these uncertainties might be acceptable for the determination of mean sediment and Corg accumulation rates over the last century, they may not always allow the determination of a detailed geochronology, historical reconstruction, or to ascertain rates of change and fluxes. Additional tracers or geochemical data need to be used in concert to constrain the 210Pb-derived results and to properly interpret the processes recorded in vegetated coastal sediments. The framework provided in this study can be instrumental in reducing the uncertainties associated to the estimates of Corg accumulation rates in vegetated coastal sediments.
δ15N and δ13C analysis of a Posidonia sinuosa seagrass bed
Publisher: Elsevier BV
Date: 04-2006
Reconstruction of centennial-scale fluxes of chemical elements in the Australian coastal environment using seagrass archives
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.SCITOTENV.2015.09.017
Abstract: The study of a Posidonia australis sedimentary archive has provided a record of changes in element concentrations (Al, Fe, Mn, Pb, Zn, Cr, Cd, Co, As, Cu, Ni and S) over the last 3000 years in the Australian marine environment. Human-derived contamination in Oyster Harbor (SW Australia) started ~100 years ago (AD ~1900) and exponentially increased until present. This appears to be related to European colonization of Australia and the subsequent impact of human activities, namely mining, coal and metal production, and extensive agriculture. Two contamination periods of different magnitude have been identified: Expansion period (EXP, AD ~1900-1970) and Establishment period (EST, AD ~1970 to present). Enrichments of chemical elements with respect to baseline concentrations (in s les older than ~115 cal years BP) were found for all elements studied in both periods, except for Ni, As and S. The highest enrichment factors were obtained for the EST period (ranging from 1.3-fold increase in Cu to 7.2-fold in Zn concentrations) compared to the EXP period (1.1-fold increase for Cu and Cr to 2.4-fold increase for Pb). Zinc, Pb, Mn and Co concentrations during both periods were 2- to 7-fold higher than baseline levels. This study demonstrates the value of Posidonia mats as long-term archives of element concentrations and trends in coastal ecosystems. We also provide preliminary evidence on the potential for Posidonia meadows to act as significant long-term biogeochemical sinks of chemical elements.
Carbon and nitrogen stable isotope analysis of an Amphibolis griffithii seagrass bed
Publisher: Elsevier BV
Date: 11-2005
Epiphytes of Seagrasses
Publisher: Springer Netherlands
Date: 2006
Population‐specific resilience of Halophila ovalis seagrass habitat to unseasonal rainfall, an extreme climate event in estuaries
Publisher: Wiley
Date: 19-04-2021
Abstract: Extreme climate events are predicted to alter estuarine salinity gradients exposing habitat‐forming species to more frequent salinity variations. The intensity and duration of these variations, rather than the mean salinity values ecosystems are exposed to, may be more important in influencing resilience but requires further investigation. Precipitation, including the frequency, intensity and timing of occurrence, is shifting due to climate change. A global analysis on the timing of rainfall in estuarine catchments was conducted. In 80% of the case studies, the maximum daily rainfall occurred in the dry season at least once over the 40‐year period and could be classified as an extreme event. We selected an estuary in southwestern Australia and investigated the effects of an extreme rainfall event in 2017 resulting in an excess discharge of freshwater on seagrass Halophila ovalis . Adapting an approach applied for marine heatwaves using salinity data, we quantified metrics and characterised the event along the estuarine gradient. We assessed seagrass resilience by calculating resistance times based on the comparisons of biomass and leaf density data prior to, and during the event, and recovery times through assessment against historical condition. Where salinity is historically more variable, reductions in biomass were lower (higher resistance via plasticity in salinity tolerance) and meadows recovered within 9–11 months. Where salinity is historically more stable, loss of biomass was greatest (low resistance) post‐event and recovery may exceed 22 months, and potentially due to the rapid decline in salinity (−3 PSU/day). As estuaries become more hydrologically variable, these metrics provide a baseline for retrospective and future comparisons. Our results suggest seagrass resilience to hyposalinity is population specific. This understanding enables more accurate predictions about ecological responses to climate change and identifies which populations may ‘future proof’ ecosystem resilience. Synthesis . Following an extreme rainfall event, we found seagrass populations that are exposed to variable salinities recovered while those from a stable salinity environment were unable to recover within the study time frame. These findings expand upon existing evidence, derived primarily from other ecosystems, that show new sources of resilience may be uncovered by accounting for between‐population variation.
Water quality monitoring in estuarine waters using the landsat thematic mapper
Publisher: Elsevier BV
Date: 12-1993
Monitoring Seagrass Ecosystem Health—The Role of Perception in Defining Health and Indicators
Publisher: Wiley
Date: 06-2000
Effects of dredging on critical ecological processes for marine invertebrates, seagrasses and macroalgae, and the potential for management with environmental windows using Western Australia as a case study
Publisher: Elsevier BV
Date: 07-2017
A test of a functional group approach to detecting shifts in macroalgal communities along a disturbance gradient
Publisher: Inter-Research Science Center
Date: 1997
DOI: 10.3354/MEPS153125
Differences in recreationally targeted fishes between protected and fished areas of a coral reef marine park
Publisher: Elsevier BV
Date: 10-2003
Can mud (silt and clay) concentration be used to predict soil organic carbon content within seagrass ecosystems?
Publisher: Copernicus GmbH
Date: 18-01-2016
DOI: 10.5194/BG-2015-598
Abstract: Abstract. The emerging field of blue carbon science is seeking cost-effective ways to estimate the organic carbon content of soils that are bound by coastal vegetated ecosystems. Organic carbon (Corg) content in terrestrial soils and marine sediments has been correlated with mud content (i.e. silt and clay), however, empirical tests of this theory are lacking for coastal vegetated ecosystems. Here, we compiled data (n = 1345) on the relationship between Corg and mud (i.e. silt and clay, particle sizes μm) contents in seagrass ecosystems (79 cores) and adjacent bare sediments (21 cores) to address whether mud can be used to predict soil Corg content. We also combined these data with the δ13C signatures of the soil Corg to understand the sources of Corg stores. The results showed that mud is positively correlated with soil Corg content only when the contribution of seagrass-derived Corg to the sedimentary Corg pool is relatively low, such as in small and fast growing meadows of the genera Zostera, Halodule and Halophila, and in bare sediments adjacent to seagrass ecosystems. In large and long-living seagrass meadows of the genera Posidonia and Amphibolis there was a lack of, or poor relationship between mud and soil Corg content, related to a higher contribution of seagrass-derived Corg to the sedimentary Corg pool in these meadows. The relative high soil Corg contents with relatively low mud contents (i.e. mud-Corg saturation) together with significant allochthonous inputs of terrestrial organic matter could overall disrupt the correlation expected between soil Corg and mud contents. This study shows that mud (i.e. silt and clay content) is not a universal proxy for blue carbon content in seagrass ecosystems, and therefore should not be applied generally across all seagrass habitats. Mud content can only be used as a proxy to estimate soil Corg content for scaling up purposes when opportunistic and/or low biomass seagrass species (i.e. Zostera, Halodule and Halophila) are present (explaining 34 to 91% of variability), and in bare sediments (explaining 78% of the variability).
Macroalgal-sediment nutrient interactions and their importance to macroalgal nutrition in a eutrophic estuary
Publisher: Elsevier BV
Date: 03-1991
Carbon sequestration by Australian tidal marshes
Publisher: Springer Science and Business Media LLC
Date: 10-03-2017
DOI: 10.1038/SREP44071
Abstract: Australia’s tidal marshes have suffered significant losses but their recently recognised importance in CO 2 sequestration is creating opportunities for their protection and restoration. We compiled all available data on soil organic carbon (OC) storage in Australia’s tidal marshes (323 cores). OC stocks in the surface 1 m averaged 165.41 (SE 6.96) Mg OC ha −1 (range 14–963 Mg OC ha −1 ). The mean OC accumulation rate was 0.55 ± 0.02 Mg OC ha −1 yr −1 . Geomorphology was the most important predictor of OC stocks, with fluvial sites having twice the stock of OC as seaward sites. Australia’s 1.4 million hectares of tidal marshes contain an estimated 212 million tonnes of OC in the surface 1 m, with a potential CO 2 -equivalent value of $USD7.19 billion. Annual sequestration is 0.75 Tg OC yr −1 , with a CO 2 -equivalent value of $USD28.02 million per annum. This study provides the most comprehensive estimates of tidal marsh blue carbon in Australia, and illustrates their importance in climate change mitigation and adaptation, acting as CO 2 sinks and buffering the impacts of rising sea level. We outline potential further development of carbon offset schemes to restore the sequestration capacity and other ecosystem services provided by Australia tidal marshes.
Porewater nutrient fluxes in a shallow fetch-limited estuary
Publisher: Inter-Research Science Center
Date: 1999
DOI: 10.3354/MEPS183039
Physiological characteristics of the seagrass Posidonia sinuosa along a depth-related gradient of light availability
Publisher: Inter-Research Science Center
Date: 17-01-2008
DOI: 10.3354/MEPS07171
Impact of mooring activities on carbon stocks in seagrass meadows
Publisher: Springer Science and Business Media LLC
Date: 16-03-2016
DOI: 10.1038/SREP23193
Abstract: Boating activities are one of the causes that threaten seagrass meadows and the ecosystem services they provide. Mechanical destruction of seagrass habitats may also trigger the erosion of sedimentary organic carbon (C org ) stocks, which may contribute to increasing atmospheric CO 2 . This study presents the first estimates of loss of C org stocks in seagrass meadows due to mooring activities in Rottnest Island, Western Australia. Sediment cores were s led from seagrass meadows and from bare but previously vegetated sediments underneath moorings. The C org stores have been compromised by the mooring deployment from 1930s onwards, which involved both the erosion of existing sedimentary C org stores and the lack of further accumulation of C org . On average, undisturbed meadows had accumulated ~6.4 Kg C org m −2 in the upper 50 cm-thick deposits at a rate of 34 g C org m −2 yr −1 . The comparison of C org stores between meadows and mooring scars allows us to estimate a loss of 4.8 kg C org m −2 in the 50 cm-thick deposits accumulated over ca. 200 yr as a result of mooring deployments. These results provide key data for the implementation of C org storage credit offset policies to avoid the conversion of seagrass ecosystems and contribute to their preservation.
Linking Land and Sea: Different Pathways for Marine Subsidies
Publisher: Springer Science and Business Media LLC
Date: 05-05-2011
Dietary preferences of two seagrass inhabiting gastropods: Allochthonous vs autochthonous resources
Publisher: Elsevier BV
Date: 06-2009
Effects of experimental reduction of light availability on the seagrass Amphibolis griffithii
Publisher: Inter-Research Science Center
Date: 24-07-2007
DOI: 10.3354/MEPS342117
Variability in the Carbon Storage of Seagrass Habitats and Its Implications for Global Estimates of Blue Carbon Ecosystem Service
Publisher: Public Library of Science (PLoS)
Date: 05-09-2013
Short-term Responses of Posidonia australis to Changes in Light Quality
Publisher: Frontiers Media SA
Date: 17-01-2018
Mechanisms and ecological role of carbon transfer within coastal seascapes
Publisher: Wiley
Date: 26-08-2013
DOI: 10.1111/BRV.12055
Abstract: Worldwide, coastal systems provide some of the most productive habitats, which potentially influence a range of marine and terrestrial ecosystems through the transfer of nutrients and energy. Several reviews have examined aspects of connectivity within coastal seascapes, but the scope of those reviews has been limited to single systems or single vectors. We use the transfer of carbon to examine the processes of connectivity through multiple vectors in multiple ecosystems using four coastal seascapes as case studies. We discuss and compare the main vectors of carbon connecting different ecosystems, and then the natural and human-induced factors that influence the magnitude of effect for those vectors on recipient systems. Vectors of carbon transfer can be grouped into two main categories: detrital particulate organic carbon (POC) and its associated dissolved organic and inorganic carbon (DOC/DIC) that are transported passively and mobile consumers that transport carbon actively. High proportions of net primary production can be exported over meters to hundreds of kilometers from seagrass beds, algal reefs and mangroves as POC, with its export dependent on wind-generated currents in the first two of these systems and tidal currents for the last. By contrast, saltmarshes export large quantities of DOC through tidal movement, while land run-off plays a critical role in the transport of terrestrial POC and DOC into temperate fjords. Nekton actively transfers carbon across ecosystem boundaries through foraging movements, ontogenetic migrations, or 'trophic relays', into and out of seagrass beds, mangroves or saltmarshes. The magnitude of these vectors is influenced by: the hydrodynamics and geomorphology of the region the characteristics of the carbon vector, such as their particle size and buoyancy and for nekton, the extent and frequency of migrations between ecosystems. Through a risk-assessment process, we have identified the most significant human disturbances that affect the integrity of connectivity among ecosystems. Loss of habitat, net primary production (NPP) and overfishing pose the greatest risks to carbon transfer in temperate saltmarsh and tropical estuaries, particularly through their effects on nekton abundance and movement. In comparison, habitat/NPP loss and climate change are likely to be the major risks to carbon transfer in temperate fjords and temperate open coasts through alteration in the amount of POC and/or DOC/DIC being transported. While we have highlighted the importance of these vectors in coastal seascapes, there is limited quantitative data on the effects of these vectors on recipient systems. It is only through quantifying those subsidies that we can effectively incorporate complex interactions into the management of the marine environment and its resources.
Nitrate reductase activity in macroalgae and its vertical distribution in macroalgal epiphytes of seagrasses
Publisher: Inter-Research Science Center
Date: 2005
DOI: 10.3354/MEPS288103
Response of the seagrass Halophila ovalis to altered light quality in a simulated dredge plume
Publisher: Elsevier BV
Date: 08-2017
DOI: 10.1016/J.MARPOLBUL.2017.05.060
Abstract: Seagrass meadows are globally threatened, largely through activities that reduce light quantity (photosynthetic photon flux density) such as dredging. However, these activities can simultaneously alter the spectral quality of light. Previous studies showed that Halophila ovalis seagrass productivity is reduced under monochromatic yellow/green light, wavelengths associated with dredge plumes, but it is unclear how they respond to spectra produced by real dredging projects. We simultaneously subjected adult H. ovalis plants to altered light quality and quantity simulating a real commercial dredging operation (15mgL
Swan grazing on seagrass: Abundance but not grazing pressure varies over an annual cycle in a temperate estuary
Publisher: CSIRO Publishing
Date: 2014
DOI: 10.1071/MF13126
Abstract: Herbivorous waterfowl such as black swans are significant grazers in temperate waterbodies their abundance, distribution and grazing rates vary over seasonal cycles. The present study examined spatial and temporal variation in the abundance and grazing rates of black swans in the Lower Swan River estuary, Western Australia, using visual surveys over 1 year (2009), and potential drivers of this variation, food sources and disturbance factors were assessed. We predicted that swan abundance and grazing pressure would be greater in summer and autumn when seasonal wetlands dry and the abundance of food sources would positively influence their distribution, whereas the level of disturbance would have a negative effect. Plant–grazer interactions are dynamic and complex the present study revealed new findings on the seasonality of this relationship, where swan abundance but not grazing pressure varied over an annual cycle. Maximum swan abundance occurred in autumn (185) with minima in spring (53) but the swan grazing pressure did not vary between seasons, ranging from 6% to 25% of seagrass production consumed. Swan abundance was a function of season and the cover of seagrass. Key hot spots for swan abundance were identified where management efforts could be targeted by minimising human disturbances and protecting seagrass.
Location and Associated Carbon Storage of Erosional Escarpments of Seagrass Posidonia Mats
Publisher: Frontiers Media SA
Date: 31-03-2201
Recovery from the impact of light reduction on the seagrass Amphibolis griffithii, insights for dredging management
Publisher: Elsevier BV
Date: 02-2011
DOI: 10.1016/J.MARPOLBUL.2010.11.001
Abstract: A large-scale, manipulative experiment was conducted to examine the extent and rate of recovery of meadows of the temperate Australian seagrass, Amphibolis griffithii to different light-reduction scenarios typical of dredging operations, and to identify potential indicators of recovery from light reduction stress. Shade cloth was used to mimic different intensities, durations and start times of light reduction, and then was removed to assess the recovery. The meadow could recover from 3 months of light stress (5-18% ambient) following 10 months re-exposure to ambient light, even when up to 72% of leaf biomass was lost, much faster recovery rates than has previously been observed for large seagrasses. However, when the meadow had been shaded for 6-9 months and more than 82% of leaf biomass was lost, no recovery was detected up to 23 months after the light stress had ceased, consistent with other studies. Five potential indicators of recovery were recommended.
Millennial-scale changes in the molecular composition of Posidonia australis seagrass deposits: Implications for Blue Carbon sequestration
Publisher: Elsevier BV
Date: 11-2019
Seagrass meadows as a globally significant carbonate reservoir
Publisher: Copernicus GmbH
Date: 06-03-2015
Abstract: Abstract. There has been a growing interest in quantifying the capacity of seagrass ecosystems to act as carbon sinks as a natural way of offsetting anthropogenic carbon emissions to the atmosphere. However, most of the efforts have focused on the organic carbon (POC) stocks and accumulation rates and ignored the inorganic carbon (PIC) fraction, despite important carbonate pools associated with calcifying organisms inhabiting the meadows, such as epiphytes and benthic invertebrates, and despite the relevance that carbonate precipitation and dissolution processes have in the global carbon cycle. This study offers the first assessment of the global PIC stocks in seagrass sediments using a synthesis of published and unpublished data on sediment carbonate concentration from 402 vegetated and 34 adjacent un-vegetated sites. PIC stocks in the top 1 m sediments ranged between 3 and 1660 Mg PIC ha-1, with an average of 654 ± 24 Mg PIC ha-1, exceeding about 5 fold those of POC reported in previous studies. Sedimentary carbonate stocks varied across seagrass communities, with meadows dominated by Halodule, Thalassia or Cymodocea supporting the highest PIC stocks, and tended to decrease polewards at a rate of -8 ± 2 Mg PIC ha-1 degree-1 of latitude (GLM, p 0.0003). Using PIC concentration and estimates of sediment accretion in seagrass meadows, mean PIC accumulation rates in seagrass sediments is 126.3 ± 0.7 g PIC m-2 y-1. Based on the global extent of seagrass meadows (177 000 to 600 000 km2), these ecosystems globally store between 11 and 39 Pg of PIC in the top meter of sediment and accumulate between 22 and 76 Tg PIC y-1, representing a significant contribution to the carbonate dynamics of coastal areas. Despite that these high rates of carbonate accumulation imply CO2 emissions from precipitation, seagrass meadows are still strong CO2 sinks as demonstrates the comparison of carbon (POC and POC) stocks between vegetated and adjacent un-vegetated sediments.
Canopy-scale modifications of the seagrass Amphibolis griffithii in response to and recovery from light reduction
Publisher: Elsevier BV
Date: 06-2014
Habitat preferences of macroinvertebrate fauna among seagrasses with varying structural forms
Publisher: Elsevier BV
Date: 2013
Shade-induced response and recovery of the seagrass Posidonia sinuosa
Publisher: Elsevier BV
Date: 03-2009
Export of detached macroalgae from reefs to adjacent seagrass beds
Publisher: Springer Science and Business Media LLC
Date: 02-12-2005
DOI: 10.1007/S00442-005-0318-7
Abstract: Trophic linkages across habitats are thought to be strong when areas of different productivity are juxtaposed. Reefs dominated by macroalgae are commonly juxtaposed to less productive seagrass beds. We tested if macroalgae detached from 12 rocky reefs in south-western Australia were exported to adjacent seagrass beds and consumed by seagrass-associated fauna. We also assessed the extent of linkages by testing for patterns in biomass and consumption of reef algae, and density of herbivorous fish with increasing distance away from reefs. Detached reef algae were found in seagrass beds adjacent to all reefs. The biomass varied among reefs and with distance from reef, but detached reef algae within the seagrass beds comprised up to 23% (mean 3.6% +/- 0.7 SE) of attached algae growing on an equivalent area of reef. Maximum accumulations were found immediately adjacent to reefs (0 m) and at the furthest distance away (>300 m). Kelp (Ecklonia radiata) dominated the attached and detached algae, and up to 77% of the biomass of E. radiata tethered in seagrass beds were consumed over 5 days (mean 11.7% +/- 0.5 SE). There were more herbivorous fish at 0 m than at >300 m away from reefs, and consumption of tethered kelp was typically highest at 0 m, but was in some cases highest at >300 m.Our study documents that, over hundreds of kilometres of coastline, macroalgae are exported from reefs to adjacent seagrass beds where they are consumed by seagrass-associated fauna. While reef algae in seagrass beds may be a patchy resource at a single time, at landscape scales and over longer time periods, the supply will be relatively predictable. We therefore suggest that detached reef algae form a significant trophic link between reefs and seagrass beds, and that this trophic link extends to distances of at least hundreds of metres away from in idual reefs.
Retrospective analysis of epiphyte assemblages in relation to seagrass loss in a eutrophic coastal embayment
Publisher: Inter-Research Science Center
Date: 28-02-2023
DOI: 10.3354/MEPS06993
Morphological, growth and meadow characteristics of the seagrass Posidonia sinuosa along a depth-related gradient of light availability
Publisher: Inter-Research Science Center
Date: 14-05-2007
DOI: 10.3354/MEPS337103
Can mud (silt and clay) concentration be used to predict soil organic carbon content within seagrass ecosystems?
Publisher: Copernicus GmbH
Date: 07-09-2016
Abstract: Abstract. The emerging field of blue carbon science is seeking cost-effective ways to estimate the organic carbon content of soils that are bound by coastal vegetated ecosystems. Organic carbon (Corg) content in terrestrial soils and marine sediments has been correlated with mud content (i.e., silt and clay, particle sizes 63 µm), however, empirical tests of this theory are lacking for coastal vegetated ecosystems. Here, we compiled data (n = 1345) on the relationship between Corg and mud contents in seagrass ecosystems (79 cores) and adjacent bare sediments (21 cores) to address whether mud can be used to predict soil Corg content. We also combined these data with the δ13C signatures of the soil Corg to understand the sources of Corg stores. The results showed that mud is positively correlated with soil Corg content only when the contribution of seagrass-derived Corg to the sedimentary Corg pool is relatively low, such as in small and fast-growing meadows of the genera Zostera, Halodule and Halophila, and in bare sediments adjacent to seagrass ecosystems. In large and long-living seagrass meadows of the genera Posidonia and Amphibolis there was a lack of, or poor relationship between mud and soil Corg content, related to a higher contribution of seagrass-derived Corg to the sedimentary Corg pool in these meadows. The relatively high soil Corg contents with relatively low mud contents (e.g., mud-Corg saturation) in bare sediments and Zostera, Halodule and Halophila meadows was related to significant allochthonous inputs of terrestrial organic matter, while higher contribution of seagrass detritus in Amphibolis and Posidonia meadows disrupted the correlation expected between soil Corg and mud contents. This study shows that mud is not a universal proxy for blue carbon content in seagrass ecosystems, and therefore should not be applied generally across all seagrass habitats. Mud content can only be used as a proxy to estimate soil Corg content for scaling up purposes when opportunistic and/or low biomass seagrass species (i.e., Zostera, Halodule and Halophila) are present (explaining 34 to 91 % of variability), and in bare sediments (explaining 78 % of the variability). The results obtained could enable robust scaling up exercises at a low cost as part of blue carbon stock assessments.
Key biogeochemical factors affecting soil carbon storage in <i>Posidonia</i> meadows
Publisher: Copernicus GmbH
Date: 15-08-2016
Abstract: Abstract. Biotic and abiotic factors influence the accumulation of organic carbon (Corg) in seagrass ecosystems. We surveyed Posidonia sinuosa meadows growing in different water depths to assess the variability in the sources, stocks and accumulation rates of Corg. We show that over the last 500 years, P. sinuosa meadows closer to the upper limit of distribution (at 2–4 m depth) accumulated 3- to 4-fold higher Corg stocks (averaging 6.3 kg Corg m−2) at 3- to 4-fold higher rates (12.8 g Corg m−2 yr−1) compared to meadows closer to the deep limits of distribution (at 6–8 m depth 1.8 kg Corg m−2 and 3.6 g Corg m−2 yr−1). In shallower meadows, Corg stocks were mostly derived from seagrass detritus (88 % in average) compared to meadows closer to the deep limit of distribution (45 % on average). In addition, soil accumulation rates and fine-grained sediment content ( 0.125 mm) in shallower meadows (2.0 mm yr−1 and 9 %, respectively) were approximately 2-fold higher than in deeper meadows (1.2 mm yr−1 and 5 %, respectively). The Corg stocks and accumulation rates accumulated over the last 500 years in bare sediments (0.6 kg Corg m−2 and 1.2 g Corg m−2 yr−1) were 3- to 11-fold lower than in P. sinuosa meadows, while fine-grained sediment content (1 %) and seagrass detritus contribution to the Corg pool (20 %) were 8- and 3-fold lower than in Posidonia meadows, respectively. The patterns found support the hypothesis that Corg storage in seagrass soils is influenced by interactions of biological (e.g., meadow productivity, cover and density), chemical (e.g., recalcitrance of Corg stocks) and physical (e.g., hydrodynamic energy and soil accumulation rates) factors within the meadow. We conclude that there is a need to improve global estimates of seagrass carbon storage accounting for biogeochemical factors driving variability within habitats.
Seagrass sediments reveal the long‐term deterioration of an estuarine ecosystem
Publisher: Wiley
Date: 28-01-2016
DOI: 10.1111/GCB.13195
Abstract: The study of a Posidonia australis sediment archive has provided a record of ecosystem dynamics and processes over the last 600 years in Oyster Harbour (SW Australia). Ecosystem shifts are a widespread phenomenon in coastal areas, and this study identifies baseline conditions and the time-course of ecological change (cycles, trends, resilience and thresholds of ecosystem change) under environmental stress in seagrass-dominated ecosystem. The shifts in the concentrations of chemical elements, carbonates, sediments <0.125 mm and stable carbon isotope signatures (δ(13) C) of the organic matter were detected between 1850s and 1920s, whereas the shift detected in P concentration occurred several decades later (1960s). The first degradation phase (1850s-1950s) follows the onset of European settlement in Australia and was characterized by a strong increase in sediment accumulation rates and fine-grained particles, driven primarily by enhanced run-off due to land clearance and agriculture in the catchment. About 80% of total seagrass area at Oyster Harbour was lost during the second phase of environmental degradation (1960s until present). The sharp increase in P concentration and the increasing contribution of algae and terrestrial inputs into the sedimentary organic matter pool around 1960s provides compelling evidence of the documented eutrophication of the estuary and the subsequent loss of seagrass meadows. The results presented demonstrate the power of seagrass sedimentary archives to reconstruct the trajectories of anthropogenic pressures on estuarine ecosystem and the associated regime shifts, which can be used to improve the capacity of scientists and environmental managers to understand, predict and better manage ecological change in these ecosystems.
Species Traits and Geomorphic Setting as Drivers of Global Soil Carbon Stocks in Seagrass Meadows
Publisher: American Geophysical Union (AGU)
Date: 10-2022
DOI: 10.1029/2022GB007481
Abstract: Our knowledge of the factors that can influence the stock of organic carbon (OC) that is stored in the soil of seagrass meadows is evolving, and several causal effects have been used to explain the variation of stocks observed at local to national scales. To gain a global‐scale appreciation of the drivers that cause variation in soil OC stocks, we compiled data on published species‐specific traits and OC stocks from monospecific and mixed meadows at multiple geomorphological settings. Species identity was recognized as an influential driver of soil OC stocks, despite their large intraspecific variation. The most important seagrass species traits associated with OC stocks were the number of leaves per seagrass shoot, belowground biomass, leaf lifespan, aboveground biomass, leaf lignin, leaf breaking force and leaf OC plus the coastal geomorphology of the area, particularly for lagoon environments. A revised estimate of the global average soil OC stock to 20 cm depth of 15.4 Mg C ha −1 is lower than previously reported. The largest stocks were still recorded in Mediterranean seagrass meadows. Our results specifically identify Posidonia oceanica from the Mediterranean and, more generally, large and persistent species as key in providing climate regulation services, and as priority species for conservation for this specific ecosystem service.
The dynamics of unattached benthic macroalgal accumulations in the Swan–Canning Estuary
Publisher: Wiley
Date: 09-2001
DOI: 10.1002/HYP.292
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.
Interactive effects of timing, intensity and duration of experimental shading on Amphibolis griffithii
Publisher: Inter-Research Science Center
Date: 18-11-2009
DOI: 10.3354/MEPS08242
Seagrass Halophila ovalis is affected by light quality across different life history stages
Publisher: Inter-Research Science Center
Date: 31-05-2017
DOI: 10.3354/MEPS12105
Supplementary material to "Reviews and syntheses: <sup>210</sup>Pb-derived sediment and carbon accumulation rates in vegetated coastal ecosystems: setting the reco
Publisher: Copernicus GmbH
Date: 10-04-2018
Flow velocity and nutrient uptake in marine canopies
Publisher: Inter-Research Science Center
Date: 18-07-2019
DOI: 10.3354/MEPS12987
Patchiness in assemblages of epiphytic macroalgae on Posidonia coriacea at a hierarchy of spatial scales
Publisher: Inter-Research Science Center
Date: 2000
DOI: 10.3354/MEPS192127
The Nutritional Eco-physiology of Chaetomorpha linum and Ulva rigida in Peel Inlet, Western Australia
Publisher: Walter de Gruyter GmbH
Date: 1991
Light reductions drive macroinvertebrate changes in Amphibolis griffithii seagrass habitat
Publisher: Inter-Research Science Center
Date: 22-02-2010
DOI: 10.3354/MEPS08367
Seagrass soil archives reveal centennial-scale metal smelter contamination while acting as natural filters
Publisher: Elsevier BV
Date: 02-2019
DOI: 10.1016/J.SCITOTENV.2018.08.400
Abstract: The upper Spencer Gulf in South Australia hosts the world's largest single stream Pb-Zn smelter, which has caused environmental and health issues related to elevated metal concentrations in the surrounding environment. The area also has extensive seagrass meadows, occupying >4000 km
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.
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