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Audzijonyte A, Delius GW, Stuart-Smith RD, Novaglio C, Edgar GJ, Barrett NS, Blanchard JL. Changes in sea floor productivity are crucial to understanding the impact of climate change in temperate coastal ecosystems according to a new size-based model. PLoS Biol 2023; 21:e3002392. [PMID: 38079442 PMCID: PMC10712853 DOI: 10.1371/journal.pbio.3002392] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Accepted: 10/19/2023] [Indexed: 12/18/2023] Open
Abstract
The multifaceted effects of climate change on physical and biogeochemical processes are rapidly altering marine ecosystems but often are considered in isolation, leaving our understanding of interactions between these drivers of ecosystem change relatively poor. This is particularly true for shallow coastal ecosystems, which are fuelled by a combination of distinct pelagic and benthic energy pathways that may respond to climate change in fundamentally distinct ways. The fish production supported by these systems is likely to be impacted by climate change differently to those of offshore and shelf ecosystems, which have relatively simpler food webs and mostly lack benthic primary production sources. We developed a novel, multispecies size spectrum model for shallow coastal reefs, specifically designed to simulate potential interactive outcomes of changing benthic and pelagic energy inputs and temperatures and calculate the relative importance of these variables for the fish community. Our model, calibrated using field data from an extensive temperate reef monitoring program, predicts that changes in resource levels will have much stronger impacts on fish biomass and yields than changes driven by physiological responses to temperature. Under increased plankton abundance, species in all fish trophic groups were predicted to increase in biomass, average size, and yields. By contrast, changes in benthic resources produced variable responses across fish trophic groups. Increased benthic resources led to increasing benthivorous and piscivorous fish biomasses, yields, and mean body sizes, but biomass decreases among herbivore and planktivore species. When resource changes were combined with warming seas, physiological responses generally decreased species' biomass and yields. Our results suggest that understanding changes in benthic production and its implications for coastal fisheries should be a priority research area. Our modified size spectrum model provides a framework for further study of benthic and pelagic energy pathways that can be easily adapted to other ecosystems.
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Affiliation(s)
- Asta Audzijonyte
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
- Centre for Marine Socioecology, University of Tasmania, Hobart, Australia
| | - Gustav W. Delius
- Department of Mathematics, University of York, York, United Kingdom
| | - Rick D. Stuart-Smith
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Camilla Novaglio
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
- Centre for Marine Socioecology, University of Tasmania, Hobart, Australia
| | - Graham J. Edgar
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Neville S. Barrett
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Julia L. Blanchard
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
- Centre for Marine Socioecology, University of Tasmania, Hobart, Australia
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Gahan J, Bellwood DR, Nankervis L, Tebbett SB. Spatial and temporal variability in tropical off-reef zooplankton across broad spatial and temporal scales. MARINE ENVIRONMENTAL RESEARCH 2023; 191:106169. [PMID: 37703670 DOI: 10.1016/j.marenvres.2023.106169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 08/08/2023] [Accepted: 09/03/2023] [Indexed: 09/15/2023]
Abstract
Productivity of oligotrophic coral reefs is largely dependent on the constant influx of zooplankton. However, our understanding of how zooplankton communities in tropical reef-associated regions vary over large spatial and temporal scales is limited. Using the Australian continuous plankton recorder dataset, we explored if, and to what extent, the off-reef zooplankton community along the Queensland shelf (including most of the Great Barrier Reef lagoon) varied with latitude, month, and diel time. The zooplankton community was consistently dominated by copepods (∼60%) which, with appendicularians, chaetognaths, non-copepod crustaceans, and thaliaceans, comprised ∼98% of the zooplankton. However, the abundance of these taxonomic groups did not vary predictably across latitude, month, or diel time, with these gradients only explaining 5% of community variation. At the scales sampled herein the composition of zooplankton was highly predictable in terms of broad taxonomic groups but variation in the relative abundance of these groups was not predictable.
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Affiliation(s)
- James Gahan
- Research Hub for Coral Reef Ecosystem Functions, James Cook University, Townsville, Queensland, 4811, Australia; College of Science and Engineering, James Cook University, Townsville, Queensland, 4811, Australia.
| | - David R Bellwood
- Research Hub for Coral Reef Ecosystem Functions, James Cook University, Townsville, Queensland, 4811, Australia; College of Science and Engineering, James Cook University, Townsville, Queensland, 4811, Australia
| | - Leo Nankervis
- College of Science and Engineering, James Cook University, Townsville, Queensland, 4811, Australia; Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville, Queensland, 4811, Australia
| | - Sterling B Tebbett
- Research Hub for Coral Reef Ecosystem Functions, James Cook University, Townsville, Queensland, 4811, Australia; College of Science and Engineering, James Cook University, Townsville, Queensland, 4811, Australia
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3
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Wolfe K, Desbiens AA, Mumby PJ. Emigration patterns of motile cryptofauna and their implications for trophic functioning in coral reefs. Ecol Evol 2023; 13:e9960. [PMID: 37006892 PMCID: PMC10049886 DOI: 10.1002/ece3.9960] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 03/07/2023] [Accepted: 03/15/2023] [Indexed: 03/30/2023] Open
Abstract
Patterns of movement of marine species can reflect strategies of reproduction and dispersal, species' interactions, trophodynamics, and susceptibility to change, and thus critically inform how we manage populations and ecosystems. On coral reefs, the density and diversity of metazoan taxa are greatest in dead coral and rubble, which are suggested to fuel food webs from the bottom up. Yet, biomass and secondary productivity in rubble is predominantly available in some of the smallest individuals, limiting how accessible this energy is to higher trophic levels. We address the bioavailability of motile coral reef cryptofauna based on small-scale patterns of emigration in rubble. We deployed modified RUbble Biodiversity Samplers (RUBS) and emergence traps in a shallow rubble patch at Heron Island, Great Barrier Reef, to detect community-level differences in the directional influx of motile cryptofauna under five habitat accessibility regimes. The mean density (0.13-4.5 ind cm-3) and biomass (0.14-5.2 mg cm-3) of cryptofauna were high and varied depending on microhabitat accessibility. Emergent zooplankton represented a distinct community (dominated by the Appendicularia and Calanoida) with the lowest density and biomass, indicating constraints on nocturnal resource availability. Mean cryptofauna density and biomass were greatest when interstitial access within rubble was blocked, driven by the rapid proliferation of small harpacticoid copepods from the rubble surface, leading to trophic simplification. Individuals with high biomass (e.g., decapods, gobies, and echinoderms) were greatest when interstitial access within rubble was unrestricted. Treatments with a closed rubble surface did not differ from those completely open, suggesting that top-down predation does not diminish rubble-derived resources. Our results show that conspecific cues and species' interactions (e.g., competition and predation) within rubble are most critical in shaping ecological outcomes within the cryptobiome. These findings have implications for prey accessibility through trophic and community size structuring in rubble, which may become increasingly relevant as benthic reef complexity shifts in the Anthropocene.
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Affiliation(s)
- Kennedy Wolfe
- Marine Spatial Ecology Lab, School of Biological Sciences and ARC Centre of Excellence for Coral Reef StudiesUniversity of QueenslandBrisbaneQueensland4072Australia
| | - Amelia A. Desbiens
- Marine Spatial Ecology Lab, School of Biological Sciences and ARC Centre of Excellence for Coral Reef StudiesUniversity of QueenslandBrisbaneQueensland4072Australia
| | - Peter J. Mumby
- Marine Spatial Ecology Lab, School of Biological Sciences and ARC Centre of Excellence for Coral Reef StudiesUniversity of QueenslandBrisbaneQueensland4072Australia
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4
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Stella JS, Wolfe K, Roff G, Rogers A, Priest M, Golbuu Y, Mumby PJ. Functional and phylogenetic responses of motile cryptofauna to habitat degradation. J Anim Ecol 2022; 91:2203-2219. [PMID: 36054747 PMCID: PMC9826372 DOI: 10.1111/1365-2656.13809] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 08/30/2022] [Indexed: 01/11/2023]
Abstract
Biodiversity of terrestrial and marine ecosystems, including coral reefs, is dominated by small, often cryptic, invertebrate taxa that play important roles in ecosystem structure and functioning. While cryptofauna community structure is determined by strong small-scale microhabitat associations, the extent to which ecological and environmental factors shape these communities are largely unknown, as is the relative importance of particular microhabitats in supporting reef trophodynamics from the bottom up. The goal of this study was to address these knowledge gaps, provided coral reefs are increasingly exposed to multiple disturbances and environmental gradients that influence habitat complexity, condition and ecosystem functioning. We compared the density, biomass, size range, phylogenetic diversity and functional roles of motile cryptofauna in Palau, Western Micronesia, among four coral-derived microhabitats representing various states of degradation (live coral [Acropora and Pocillopora], dead coral and coral rubble) from reefs along a gradient of effluent exposure. In total, 122 families across ten phyla were identified, dominated by the Arthropoda (Crustacea) and Mollusca. Cryptofauna biomass was greatest in live Pocillopora, while coral rubble contained the greatest density and diversity. Size ranges were broader in live corals than both dead coral and rubble. From a bottom-up perspective, effluent exposure had mixed effects on cryptic communities including a decline in total biomass in rubble. From a top-down perspective, cryptofauna were generally unaffected by predator biomass. Our data show that, as coral reef ecosystems continue to decline in response to more frequent and severe disturbances, habitats other than live coral may become increasingly important in supporting coral reef biodiversity and food webs.
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Affiliation(s)
- Jessica S. Stella
- The Great Barrier Reef Marine Park AuthorityTownsvilleQueenslandAustralia
| | - Kennedy Wolfe
- Marine Spatial Ecology Lab, School of Biological Sciences and ARC Centre of Excellence for Coral Reef StudiesUniversity of QueenslandSt LuciaQueenslandAustralia
| | - George Roff
- Marine Spatial Ecology Lab, School of Biological Sciences and ARC Centre of Excellence for Coral Reef StudiesUniversity of QueenslandSt LuciaQueenslandAustralia
| | - Alice Rogers
- Victoria University of Wellington, School of Biological SciencesWellingtonNew Zealand
| | - Mark Priest
- Marine Spatial Ecology Lab, School of Biological Sciences and ARC Centre of Excellence for Coral Reef StudiesUniversity of QueenslandSt LuciaQueenslandAustralia
| | | | - Peter J. Mumby
- Marine Spatial Ecology Lab, School of Biological Sciences and ARC Centre of Excellence for Coral Reef StudiesUniversity of QueenslandSt LuciaQueenslandAustralia
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Heather FJ, Stuart-Smith RD, Blanchard JL, Fraser KM, Edgar GJ. Reef communities show predictable undulations in linear abundance size spectra from copepods to sharks. Ecol Lett 2021; 24:2146-2154. [PMID: 34291561 DOI: 10.1111/ele.13844] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 06/02/2021] [Accepted: 06/10/2021] [Indexed: 01/29/2023]
Abstract
Among the more widely accepted general hypotheses in ecology is that community relationships between abundance and body size follow a log-linear size spectrum, from the smallest consumers to the largest predators (i.e. 'bacteria to whales'). Nevertheless, most studies only investigate small subsets of this spectrum, and note that extreme size classes in survey data deviate from linear expectations. In this study, we fit size spectra to field data from 45 rocky and coral reef sites along a 28° latitudinal gradient, comprising individuals from 0.125 mm to 2 m in body size. We found that 96% of the variation in abundance along this 'extended' size gradient was described by a single linear function across all sites. However, consistent 'wobbles' were also observed, with subtle peaks and troughs in abundance along the spectrum, which varied with sea temperature, as predicted by theory relating to trophic cascades.
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Affiliation(s)
- Freddie J Heather
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | - Rick D Stuart-Smith
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | - Julia L Blanchard
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | - Kate M Fraser
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | - Graham J Edgar
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
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