ORCID Profile
0000-0002-6510-0825
Current Organisations
University of Melbourne
,
University of Tasmania
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Publisher: Cold Spring Harbor Laboratory
Date: 06-09-2021
DOI: 10.1101/2021.09.05.459038
Abstract: Global seaweed carbon sequestration estimates are currently taken as the fraction of the net primary production ( NPP ) exported to the deep ocean. However, this perspective does not account for CO 2 from the consumption of external subsidies. Here we clarify: i) the role of export relative to seaweed net ecosystem production ( NEP ) for a closed system and one more likely open to subsidies ii) the importance of subsidies by compiling published estimates of NEP from seaweed-dominated ecosystems and iii) discuss their impact on the global seaweed net carbon balance and other sequestration constraints as a mitigation service. Ex les of seaweed NEP (n = 18) were sparse and variable. Nevertheless, the average NEP (−9.2mmol C m −2 day −1 SE ± 11.6) suggested that seaweed ecosystems are a C source, becoming increasingly heterotrophic as their export is consumed. Critically, mitigation of greenhouse gas emissions was mixed relative to their replacement or baseline states, and where CO 2 is supplied independently of organic metabolism and atmospheric exchange we caution a sole reliance on NEP or NPP . This will ensure a more accurate seaweed mitigation assessment, one that does exceed their capacity and is effective within a compliance and carbon trading scheme.
Publisher: Wiley
Date: 09-05-2022
DOI: 10.1002/AQC.3825
Abstract: The patch dynamics of foundation species profoundly affects community assembly and thus has important implications for ecosystem restoration. However, it is unclear how restored kelp patches that vary in size and density will influence the establishment of mid‐trophic level (MTL) macroinvertebrates, a key functional group in coastal ecosystems. Artificial reefs with transplants of the canopy‐forming kelp, Ecklonia radiata , were used to quantify the effect of patch size and kelp density on the densities of MTL macroinvertebrates (primarily decapod crustaceans) and on the recruitment of an ecologically important and commercially valuable lobster species. Densities of MTL macroinvertebrates, which were dominated by hermit crabs, decreased with increasing patch size but responded inconsistently to kelp density. There was, however, an overall positive relationship between MTL macroinvertebrates and the density of small epifaunal grazers (a potential food source), along with a negative association with cover of understorey foliose algae. In contrast, the total abundance and density of lobster recruits was higher on larger reefs, and reefs with kelp had up to double the number of recruits relative to reefs with no kelp. After 12 months, most of the surviving lobster recruits occurred on reefs supporting low and medium densities of kelp. These results show that patchy reef substratum is effective in supporting high densities of some MTL macroinvertebrates, irrespective of kelp presence. Although conversely, larger reefs with restored kelp at natural – or even relatively low – densities appear critical to the recruitment of lobsters, which could motivate and provide positive feedback for kelp restoration projects in some locations. Patch dynamics may be used to support restoration efforts by helping to accelerate the recovery of key species and ecosystem services however, trade‐offs will exist through different taxa responding to patch characteristics in different ways, some positive and some negative.
Publisher: Wiley
Date: 27-08-2019
DOI: 10.1111/REC.13019
Publisher: Springer Science and Business Media LLC
Date: 09-2022
DOI: 10.1007/S10811-022-02822-Y
Abstract: The bio ersity benefits of kelp aquaculture and afforestation are increasingly acclaimed as the industry continues to grow and develop globally, however, whether farmed kelp can provide this ecosystem service remains unclear. Using peer-reviewed literature, we evaluated whether kelp farms provide bio ersity benefits, and identified only 23 studies that discussed the effects of kelp aquaculture on bio ersity, half of which were broad reviews that only assessed the concept of ‘bio ersity’ peripherally (e.g. did not focus on specific responses or taxa). There is also a general lack of experimental research on the topic. Based on the evidence, it seems that kelp farms can create habitat via changes to the local environment, particularly through the provision of structure and changed nutrient cycling. While this can lead to increased abundance and ersity among certain taxa (e.g. fouling organisms), it seems that kelp farms typically create novel habitats that support distinct communities not equivalent to natural kelp forests. Moreover, the potential for kelp farms to support bio ersity depends on a range of operational factors, many of which may be at odds with farming objectives that require the harvest and removal of the habitat that farms provide. While more work needs to be done to address the complexity of comparisons between kelp farms and forests, especially at appropriate experimental scales, it currently seems unlikely that kelp farms will act as kelp forests and deliver meaningful bio ersity outcomes. We should instead recognise farms for providing their own valuable services and support restoration and conservation practices of kelp forests to pursue bio ersity outcomes.
Publisher: Wiley
Date: 19-12-2019
DOI: 10.1111/OIK.06585
Abstract: Habitat‐forming ecosystem engineers are the foundation of many marine ecosystems where they support erse and productive food‐webs. A reduction in their patch size or density may affect the productivity, bio ersity and stability of these ecosystems. We determined the effects of different densities and patch sizes of Ecklonia radiata (the dominant kelp in southern Australia) on the secondary productivity, species richness, ersity and community structure of understory epifaunal invertebrates and how associated environmental covariates modified by kelp affected those patterns. We assessed sub‐canopy epifauna across 28 artificial reefs with transplanted E. radiata consisting of seven different patch sizes (0.12–7.68 m 2 ) crossed with four kelp densities (0–16 kelp m −2 ) over two years. Epifaunal secondary productivity associated with both natural algal and standardised rope fibre habitats decreased with patch size and was elevated when kelp was absent, however, it was also high in natural habitat when there was a high density of kelp. Epifaunal productivity was positively associated with sub‐canopy light and water flow but negatively associated with the biomass of the dominant understory alga, Ulva sp. Epifaunal ersity declined with a reduction in reef size as did richness which correlated with a loss of algal species richness. Community structure of epifauna also differed between small and large reefs, between reefs with and without kelp, between rope habitats at the centre and at the edge of reefs, and within natural habitat between reefs supporting high and low densities of kelp. Overall, these results indicate complex effects of E. radiata decline on epifaunal communities, with high secondary productivity associated with dense kelp stands, but also areas without kelp that are dominated by turf algae. While the loss of standing kelp from rocky reefs may result in declines in epifaunal bio ersity, where turf algae replaces kelp, the reefs may still support high secondary productivity.
Publisher: Wiley
Date: 07-2021
DOI: 10.1111/REC.13412
Abstract: The ability to successfully transplant adult kelp has applications not only for ecological experiments, but also for habitat conservation and restoration projects. However, approaches to the long‐term transplanting of adult kelp (especially for stalked or ‘stipitate’ species), and the communication of these methods, has been relatively haphazard, often due to poor results and excessive mortality. Here, we provide a brief communication to describe a method to effectively transplant the stipitate kelp Ecklonia radiata —the most widespread and abundant kelp in Australasia—and which allowed the transplanting of ,000 adult kelp over 1.5 ha. We also discuss additional observations relevant to the success of transplanting kelp (such as donor age/size), and the applicability of this method to other habitat‐forming macroalgae. Our method involved securing the adult Ecklonia to the substratum using large bands made from recycled rubber, which held the holdfast firmly but gently against the substratum. Re‐attachment of the adult kelp typically occurred within 3–6 weeks, while rates of survivorship were approximately 75% and not affected by the density nor size of the transplanted patch. This method could also readily be adapted to suit different substratum types and other species of kelp and habitat‐forming algae. Ultimately, this transplanting method adds to the collection of effective techniques for restoring habitat‐forming macroalgae, especially for stipitate species where few methods have been communicated.
Publisher: Cold Spring Harbor Laboratory
Date: 18-02-2023
DOI: 10.1101/2023.02.16.528770
Abstract: Marine imagery is a comparatively cost-effective way to collect data on seafloor organisms, bio ersity and habitat morphology. However, annotating these images to extract detailed biological information is time-consuming and expensive, and reference libraries of consistently annotated seafloor images are rarely publicly available. Here, we present the Antarctic Seafloor Annotated Imagery Database (AS-AID), a result of a multinational collaboration to collate and annotate regional seafloor imagery datasets from 19 Antarctic research cruises between 1985 and 2019. AS-AID comprises of 3,599 georeferenced downward facing seafloor images that have been labelled with a total of 615,051 expert annotations. Annotations are based on the CATAMI (Collaborative and Automated Tools for Analysis of Marine Imagery) classification scheme and have been reviewed by experts. In addition, because the pixel location of each annotation within each image is available, annotations can be viewed easily and customised to suit in idual research priorities. This dataset can be used to investigate species distributions, community patterns, it provides a reference to assess change through time, and can be used to train algorithms to automatically detect and annotate marine fauna.
Publisher: Oxford University Press (OUP)
Date: 19-05-2022
Abstract: The comment qualitatively suggests that seaweed ecosystems are global carbon sinks. This was in contradiction to the article that showed that seaweed ecosystems are on average measurably carbon sources within the canopy. Furthermore, this was lified by the remineralization of a large fraction of exported seaweed production, as estimated from published parameters. It appeared that the comments’ conclusion was mistaken from two standpoints. First, a view that the article did not consider the impact of the phytoplanktonic assemblage on the seaweed ecosystems’ global sequestration rate. This had been previously calculated as likely, not significant. Second, a view that the consumption and subsequent respiration of exported material cannot be included in ecosystems that are generally open to allochthonous organic carbon subsidies. Nevertheless, the comment does raise the importance of a more holistic view in assessing sequestration services. The response expands the article's arguments from different standpoints and consequences to illustrate where the comment has been mistaken, and points out where the article was misread. We also expand on the comments’ call for a more holistic approach by being more explicit on what drives both sequestration and mitigation through the extreme circumstances where this could be maximized, including phytoplankton contributions.
Publisher: Oxford University Press (OUP)
Date: 09-02-2022
Abstract: Global seaweed carbon sequestration estimates are currently taken as the fraction of the net primary production (NPP) exported to the deep ocean. However, this perspective does not account for CO2 from the consumption of external subsidies. Here, we clarify: (i) the role of export relative to seaweed net ecosystem production (NEP) for a closed system and one more likely open to subsidies (ii) the importance of subsidies by compiling published estimates of NEP from seaweed-dominated ecosystems and (iii) discuss their impact on the global seaweed net carbon balance and other sequestration constraints as a mitigation service. Ex les of seaweed NEP (n = 18) were sparse and variable. Nevertheless, the average NEP (−4.0 mmol C m–2 d–1 SE ± 12.2) suggested that seaweed ecosystems are a C source, becoming increasingly heterotrophic as their export is consumed. Critically, mitigation of greenhouse gas emissions was mixed relative to their replacement or baseline states, and where CO2 is supplied independently of organic metabolism and atmospheric exchange, we caution a sole reliance on NEP or NPP. This will ensure a more accurate seaweed mitigation assessment, one that does exceed their capacity and is effective within a compliance and carbon trading scheme.
No related grants have been discovered for Victor Shelamoff.