Modeling the effects of selectively fishing key functional groups of herbivores on coral resilience

Ecosphere, Journal Year: 2024, Volume and Issue: 15(1)

Published: Jan. 1, 2024

Abstract Mounting evidence suggests that fishing can be a major driver of coral‐to‐macroalgae regime shifts on tropical reefs. In many small‐scale coral reef fisheries, fishers target herbivorous fishes, which weaken resilience via reduced herbivory macroalgae then outcompete corals. Previous models explored the effects harvesting herbivores revealed hysteresis in herbivory–benthic state relationship results bistability coral‐ and macroalgae‐dominated states over some levels pressure, has been supported by empirical evidence. However, past have not accounted for functional differences among or how fisher selectivity different herbivore groups may alter benthic dynamics resilience. Here, we use dynamic model links differential two key to outcome competitive between macroalgae. We show depends only level but also types targeted fishers. Selectively browsing are capable consuming mature (e.g., unicornfish) increases precariousness moving system close tipping point. By contrast, selectively grazing preventing from becoming established parrotfishes) increase catch yields substantially more before point is reached. this lower with increasing effort comes at cost range bistable; makes shift triggered disturbance difficult impractical reverse. Our suggest management strategies fisheries should consider harvested coupled influence light trade‐off recovery following large disturbances.

Language: Английский

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Coral Microbiomes Demonstrate Flexibility and Resilience Through a Reduction in Community Diversity Following a Thermal Stress Event

Frontiers in Ecology and Evolution, Journal Year: 2020, Volume and Issue: 8

Published: Oct. 15, 2020

Thermal stress increases community diversity, variability, and the abundance of potentially pathogenic microbial taxa in coral microbiome. Nutrient pollution such as excess nitrogen can also interact with thermal to exacerbate host fitness degradation. However, it is unclear how different forms (nitrate vs. ammonium/urea) bleaching-level temperature drive changes microbiomes, especially on reefs histories resilience. We used a 13-month field experiment spanning event Austral summer 2016 oligotrophic fore reef Mo'orea, French Polynesia test urea) impact resistance resilience microbiomes. For Acropora, Pocillopora, Porites corals, we found no significant differences diversity metrics between control, nitrate- urea-treated corals during stress. In fact, may have overwhelmed any effects nitrogen. Although all three hosts were dominated by bacterial clade Endozoicomonas which proposed beneficial symbiont, each differed through time patterns variability. These reflect strategies for restructuring or maintaining microbiome composition cope environmental Contrary our expectation, post-stress microbiomes did not return pre-stress composition, but rather less diverse increasingly Endozoicomonas. The dominance 10 months after peak sea surface temperatures suggest its ability utilize metabolic products sustained competitive advantage against other members. If proliferation warm could provide evidence mitigate holobiont dysbiosis

Language: Английский

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Nitrogen eutrophication particularly promotes turf algae in coral reefs of the central Red Sea

PeerJ, Journal Year: 2020, Volume and Issue: 8, P. e8737 - e8737

Published: April 2, 2020

While various sources increasingly release nutrients to the Red Sea, knowledge about their effects on benthic coral reef communities is scarce. Here, we provide first comparative assessment of response all major groups (hard and soft corals, turf algae sands—together accounting for 80% community) in-situ eutrophication in a central Sea reef. For 8 weeks, dissolved inorganic nitrogen (DIN) concentrations were experimentally increased 3-fold above environmental background around natural using slow fertilizer with 15% total (N) content. We investigated which functional took up available N, how this changed organic carbon (C org ) N contents elemental stable isotope measurements. Findings revealed that hard corals (in tissue), incorporated as indicated by significant increases δ 15 8%, 27% 28%, respectively. Among groups, C content significantly sediments (+24%) (+33%). Altogether, suggests among organisms only limited availability thus benefited most from addition. Thereby, based higher content, potentially gained competitive advantage over, example, corals. Local management should, thus, particularly address DIN coastal development consider role potential bioindicator eutrophication.

Language: Английский

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Eutrophication on Coral Reefs: What Is the Evidence for Phase Shifts, Nutrient Limitation and Coral Bleaching

BioScience, Journal Year: 2021, Volume and Issue: 71(12), P. 1216 - 1233

Published: Sept. 8, 2021

Abstract Coral reefs continue to experience extreme environmental pressure from climate change stressors, but many coral are also exposed eutrophication. It has been proposed that changes in the stoichiometry of ambient nutrients increase mortality corals, whereas eutrophication may facilitate phase shifts macroalgae-dominated when herbivory is low or absent. But corals ever nutrient limited, and can destabilize symbiosis making it more sensitive stress because change? The effects confounded not just by presence chemical pollutants industrial, urban, agricultural wastes. Because these confounding effects, increases their coastal environments, although they important at organismal community level, cannot currently be disentangled each other significant stressors on reefs.

Language: Английский

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A systematic review and meta-analysis of the direct effects of nutrients on corals

The Science of The Total Environment, Journal Year: 2022, Volume and Issue: 856, P. 159093 - 159093

Published: Sept. 30, 2022

Language: Английский

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Anthropogenic nitrogen pollution threats and challenges to the health of South Asian coral reefs

Frontiers in Marine Science, Journal Year: 2023, Volume and Issue: 10

Published: May 24, 2023

Nitrogen pollution is a widespread and growing problem in the coastal waters of South Asia yet ecological impacts on region’s coral ecosystems are currently poorly known understood. hosts just under 7% global reef coverage but has experienced significant loss recent decades. The extent to which this ecosystem decline at regional scale can be attributed multiple threats posed by nitrogen been largely overlooked literature. Here, we assess evidence for corals central Indian Ocean India, Sri Lanka Maldives. We find that there limited with clearly demonstrate reefs from pollution, including its interactions other stressors such as seawater warming. However, does not prove no impacts, rather it reflects paucity appropriate observations related understanding range potential individual, species levels. This situation presents research, management conservation challenges given wide acceptance problematic. Following this, recommend more systematic collection sharing robust observations, modelling experimentation provide baseline base prescient control action.

Language: Английский

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Seabirds boost coral reef resilience

Science Advances, Journal Year: 2023, Volume and Issue: 9(49)

Published: Dec. 6, 2023

Global climate change threatens tropical coral reefs, yet local management can influence resilience. While increasing anthropogenic nutrients reduce resistance and recovery, it is unknown how the loss, or restoration, of natural nutrient flows affects reef recovery. Here, we test seabird-derived subsidies, which are threatened by invasive rats, mechanisms patterns recovery following an extreme marine heatwave using multiyear field experiments, repeated surveys, Bayesian modeling. Corals transplanted from rat to seabird islands quickly assimilated nutrients, fully acclimating new conditions within 3 years. Increased in turn, caused a doubling growth rates both individuals across entire reefs. Seabirds were also associated with faster time Acropora cover (<4 years) more dynamic trajectories benthic communities. We conclude that restoring populations pathways may foster greater resilience through enhanced corals.

Language: Английский

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Tracing the fate of seabird‐derived nitrogen in a coral reef using nitrate and coral skeleton nitrogen isotopes

Limnology and Oceanography, Journal Year: 2024, Volume and Issue: 69(2), P. 309 - 324

Published: Jan. 3, 2024

Abstract Seabirds transfer nutrients from the ocean to their nesting island, potentially altering nitrogen (N) cycling within adjacent terrestrial and marine ecosystems. Yet, processes involved in seabird‐N along land–sea continuum remain elusive. Using δ 15 N 18 O measurements of groundwater nitrate, we demonstrate role brackish located a coral island's landmass as major reservoir nitrate (at millimolar levels). Nearly all total dissolved seabird‐derived leaching into (mostly ammonium uric acid) is converted by nitrification, supported relatively low (3.97‰ ± 0.30‰). Comparison suggests that little denitrification takes place lens, implying high (13.73‰ 0.05‰) derives trophic position seabirds postdepositional increase seabird excreta. Seawater skeleton samples reef flat exposed had higher values than at sites devoid influence, indicating main source latter site was Subtropical Upper Water, while dominated pool up 200 m shore. In addition, these results indicate coral‐bound can detect N, raising opportunities reconstruct historical inputs reefs relation climatic other changes, such introduction invasive species.

Language: Английский

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Fish predation on corals promotes the dispersal of coral symbionts

Animal Microbiome, Journal Year: 2021, Volume and Issue: 3(1)

Published: March 22, 2021

Abstract Background The microbiomes of foundation (habitat-forming) species such as corals and sponges underpin the biodiversity, productivity, stability ecosystems. Consumers shape communities through trophic interactions, but role consumers in dispersing is rarely examined. For example, stony rely on a nutritional symbiosis with single-celled endosymbiotic dinoflagellates (family Symbiodiniaceae) to construct reefs. Most acquire Symbiodiniaceae from environment, processes that make available for uptake are not resolved. Here, we provide first comprehensive, reef-scale demonstration predation by diverse coral-eating (corallivorous) fish promotes dispersal Symbiodiniaceae, based symbiont cell densities community compositions feces four obligate corallivores, three facultative two grazer/detritivores well samples reef sediment water. Results Obligate corallivore environmental hotspots cells: live concentrations 5–7 orders magnitude higher than water reservoirs. corallivores similar those locally abundant coral genera ( Pocillopora Porites ), differ Combining our data situ observations fish, estimate some corallivorous release over 100 million cells per m 2 day. Released came direct contact colonies fore zone following 91% observed egestion events, providing potential mechanism transfer among colonies. Conclusions Taken together, findings show may support maintenance cover reefs an unexpected way: beneficial symbionts feces. Few studies examine species, or how reservoirs replenished. This work sets stage parallel consumer-mediated microbiome assembly other sessile, habitat-forming species.

Language: Английский

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Effect of climate change on marine ecosystems

Elsevier eBooks, Journal Year: 2021, Volume and Issue: unknown, P. 115 - 176

Published: Jan. 1, 2021

Language: Английский

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