scholarly journals Seabird nutrient subsidies alter patterns of algal abundance and fish biomass on coral reefs following a bleaching event

2019 ◽  
Vol 25 (8) ◽  
pp. 2619-2632 ◽  
Author(s):  
Cassandra E. Benkwitt ◽  
Shaun K. Wilson ◽  
Nicholas A. J. Graham
Keyword(s):  
Coral Reefs ◽  
Fish Biomass ◽  
Bleaching Event ◽  
Algal Abundance ◽  
Nutrient Subsidies

scholarly journals Nitrogen enrichment in macroalgae following mass coral mortality

Coral Reefs ◽  
2021 ◽  
Author(s):  
Eleanor J. Vaughan ◽  
Shaun K. Wilson ◽  
Samantha J. Howlett ◽  
Valeriano Parravicini ◽  
Gareth J. Williams ◽  
...  
Keyword(s):  
Coral Reefs ◽  
Coral Cover ◽  
Strong Association ◽  
French Polynesia ◽  
Mass Mortality ◽  
Transplant Experiment ◽  
Bleaching Event ◽  
Coral Mortality ◽  
Absolute Increase ◽  
Inorganic Matter

AbstractScleractinian corals are engineers on coral reefs that provide both structural complexity as habitat and sustenance for other reef-associated organisms via the release of organic and inorganic matter. However, coral reefs are facing multiple pressures from climate change and other stressors, which can result in mass coral bleaching and mortality events. Mass mortality of corals results in enhanced release of organic matter, which can cause significant alterations to reef biochemical and recycling processes. There is little known about how long these nutrients are retained within the system, for instance, within the tissues of other benthic organisms. We investigated changes in nitrogen isotopic signatures (δ15N) of macroalgal tissues (a) ~ 1 year after a bleaching event in the Seychelles and (b) ~ 3 months after the peak of a bleaching event in Mo’orea, French Polynesia. In the Seychelles, there was a strong association between absolute loss in both total coral cover and branching coral cover and absolute increase in macroalgal δ15N between 2014 and 2017 (adjusted r2 = 0.79, p = 0.004 and adjusted r2 = 0.86, p = 0.002, respectively). In Mo’orea, a short-term transplant experiment found a significant increase in δ15N in Sargassum mangarevense after specimens were deployed on a reef with high coral mortality for ~ 3 weeks (p < 0.05). We suggest that coral-derived nutrients can be retained within reef nutrient cycles, and that this can affect other reef-associated organisms over both short- and long-term periods, especially opportunistic species such as macroalgae. These species could therefore proliferate on reefs that have experienced mass mortality events, because they have been provided with both space and nutrient subsidies by the death and decay of corals.

scholarly journals A long-term, spatially replicated experimental test of the effect of marine reserves on local fish yields

2005 ◽  
Vol 62 (1) ◽  
pp. 98-108 ◽  
Author(s):  
Angel C Alcala ◽  
Garry R Russ ◽  
Aileen P Maypa ◽  
Hilconida P Calumpong
Keyword(s):  
Coral Reefs ◽  
Experimental Test ◽  
Marine Reserves ◽  
Fish Biomass ◽  
Total Catch ◽  
Target Fish ◽  
Fish Yields

Do no-take marine reserves affect fishery yields? Manipulations of reserve status, and yield estimates, were made at two Philippine islands over two decades. Twenty-five percent and ten percent, respectively, of the coral reefs at Sumilon and Apo islands were made no-take reserves in 1974 and 1982. Biomass of target fish increased inside the no-take reserves 3- to 4.5-fold over 9–18 years. Biomass did not increase outside each reserve. Protection of the Sumilon reserve ceased in 1984. Biomass of targeted fish in the reserve and trap and gillnet catches of these fish declined by 42.7% and 40%, respectively, by 1985. The reserve was reprotected from 1987 to 1991 and from 1995 to 2001. Fish biomass increased in the reserve by 27.2%. Trap and gillnet catches outside the reserve increased 26.9% by 2001. The Apo reserve was protected from 1982 to 2001. Total catch of major fish families was significantly higher after (1985–2001) than before (1981) reserve establishment at Apo, increasing 41.3% between 1981 and 1998–2001. These experiments, plus spillover evidence, suggest that marine reserves may help maintain, or even enhance, local fishery yields in the long-term.

scholarly journals The Third Global Coral Bleaching Event on the Marginal Coral Reefs of the Southwestern Indian Ocean and Factors That Contribute to Their Resistance and Resilience

Diversity ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 464
Author(s):  
Sean N. Porter ◽  
Kerry J. Sink ◽  
Michael H. Schleyer
Keyword(s):  
Indian Ocean ◽  
Coral Reefs ◽  
Coral Bleaching ◽  
Bleaching Event ◽  
Thermal Dynamics ◽  
Upwelled Water ◽  
Coral Communities ◽  
Temperature Records ◽  
Southwestern Indian Ocean

Coral reefs reach their southernmost limits in the southwestern Indian Ocean in Maputaland, South Africa. Here, we investigate the recent global coral bleaching event of 2016, the thermal dynamics of these marginal high-latitude reefs and the potential environmental factors regulating the responses of coral communities. Pre-, peak- and post-bleaching surveys of over 9850 coral colonies from 29 genera were undertaken over 3 years across 14 sites spanning 120 km of coastline using point-intercept and visual bleaching index survey methodologies. Bleaching data were related to several environmental variables including temperature, degree heating weeks (DHW), depth, latitude, and upwelling intensity. These reefs have experienced a history of relatively low thermal stress based on DHW. Long-term in situ temperature records nevertheless showed no obvious trend of increase. In situ temperatures also displayed poor relationships, with temperatures predicted by the Representative Concentration Pathway models. Mild coral bleaching with no significant mortality was recorded across sites with taxon-specific bleaching responses evident. Latitude and cumulative daily DHW were significantly related to the bleaching index whereas depth and interactions of depth with latitude and DHW were not. While upwelling of cooler water may offer some refuge to coral communities, especially in the Central and Southern Reef Complexes where it is more pronounced, this may only be transient as the upwelled water may also experience some degree of warming in future, thereby limiting such protection from global warming.

scholarly journals Comment on “Demographic dynamics of the smallest marine vertebrates fuel coral reef ecosystem functioning”

Science ◽  
2019 ◽  
Vol 366 (6472) ◽  
pp. eaay9321 ◽  
Author(s):  
Jacob E. Allgeier ◽  
Timothy J. Cline
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Ecosystem Function ◽  
Ecosystem Functioning ◽  
Fish Biomass ◽  
Fish Production ◽  
Coral Reef Ecosystem ◽  
High Productivity ◽  
Demographic Dynamics ◽  
Reef Ecosystem

Brandl et al. (Reports, 21 June 2019, p. 1189) report that cryptobenthic fishes underpin coral reef ecosystem function by contributing ~60% of “consumed fish” biomass and ~20% of production. These results are artifacts of their simulation. Using their data and model, we show that cryptobenthic species contribute less than 4% to fish production, calling into question the extent to which they contribute to the high productivity of coral reefs.

Demographic dynamics of the smallest marine vertebrates fuel coral reef ecosystem functioning

Science ◽  
2019 ◽  
Vol 364 (6446) ◽  
pp. 1189-1192 ◽  
Author(s):  
Simon J. Brandl ◽  
Luke Tornabene ◽  
Christopher H. R. Goatley ◽  
Jordan M. Casey ◽  
Renato A. Morais ◽  
...  
Keyword(s):  
Coral Reefs ◽  
Reef Fish ◽  
Ecosystem Functioning ◽  
Fish Larvae ◽  
Meta Analysis ◽  
Reef Fishes ◽  
Pelagic Zone ◽  
Fish Biomass ◽  
Demographic Dynamics ◽  
Pelagic Environment

How coral reefs survive as oases of life in low-productivity oceans has puzzled scientists for centuries. The answer may lie in internal nutrient cycling and/or input from the pelagic zone. Integrating meta-analysis, field data, and population modeling, we show that the ocean’s smallest vertebrates, cryptobenthic reef fishes, promote internal reef fish biomass production through extensive larval supply from the pelagic environment. Specifically, cryptobenthics account for two-thirds of reef fish larvae in the near-reef pelagic zone despite limited adult reproductive outputs. This overwhelming abundance of cryptobenthic larvae fuels reef trophodynamics via rapid growth and extreme mortality, producing almost 60% of consumed reef fish biomass. Although cryptobenthics are often overlooked, their distinctive demographic dynamics may make them a cornerstone of ecosystem functioning on modern coral reefs.

scholarly journals A study on the recovery of Tobago's coral reefs following the 2010 mass bleaching event

2016 ◽  
Vol 104 (1-2) ◽  
pp. 198-206 ◽  
Author(s):  
Salome Buglass ◽  
Simon D. Donner ◽  
Jahson B. Alemu I
Keyword(s):  
Coral Reefs ◽  
Bleaching Event ◽  
Mass Bleaching Event ◽  
Mass Bleaching

scholarly journals The importance of sponges and mangroves in supporting fish communities in degraded coral reefs in Caribbean Panama

2017 ◽  
Author(s):  
Janina Seemann ◽  
Alexandra Yingst ◽  
Rick D Stuart-Smith ◽  
Graham J Edgar ◽  
Andrew H Altieri
Keyword(s):  
Coral Reefs ◽  
Fish Community ◽  
Trophic Structure ◽  
Habitat Degradation ◽  
Human Impacts ◽  
Small Body ◽  
Fish Communities ◽  
Trophic Levels ◽  
Fish Biomass ◽  
Total Fish

Fish communities associated with coral reefs worldwide are threatened by overexploitation and other human impacts such as bleaching events that cause habitat degradation. We assessed the fish community on coral reefs on the Caribbean coast of Panama, as well as those associated with mangrove and seagrass habitats, to explore the influences of habitat cover, connectivity and environmental characteristics in sustaining biomass, richness and trophic structure in a degraded tropical ecosystem. Overall, 94 % of all fishes across all habitat types were of small body size (≤11 cm), with communities dominated by fishes that usually live in habitats of low complexity, such as Pomacentridae (damselfishes) and Gobiidae (gobies). Moreover, total fish biomass was very low, small fishes from low trophic levels were over-represented, and top predators were under-represented relative to other Caribbean reefs. For example, herbivorous/omnivorous/detrivorous fishes (trophic level 2-2.7) comprised 37 % of total fish biomass, with the diminutive parrotfish Scarus iseri comprising 72 % of the parrotfish biomass. However, the abundance of sponges and proximity of mangroves were found to be important positive drivers of reef fish richness, biomass and trophic structure on a given reef, presumably by promoting functional processes of ecosystems. The masked goby (Coryphopterus personata) was a strong indicator of reef degradation, apparently benefiting from the reduced density of large predators on local reefs. The damselfish Abudefduf saxatilis was more common on reefs with high sponge cover, and also to proximity to mangroves. Our study suggests that a diverse fish community can persist on degraded coral reefs, and that the availability of habitat forming organisms other than corals, including sponges and mangroves, and their arrangement on the landscape, is critical to the maintenance of functional processes in these ecosystems.

scholarly journals Conservation actions and ecological context: optimizing coral reef local management in the Dominican Republic

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10925
Author(s):  
Camilo Cortés-Useche ◽  
Edwin A. Hernández-Delgado ◽  
Johanna Calle-Triviño ◽  
Rita Sellares Blasco ◽  
Victor Galván ◽  
...  
Keyword(s):  
Dominican Republic ◽  
Coral Reefs ◽  
Global Climate Change ◽  
Coral Cover ◽  
Global Climate ◽  
Fish Biomass ◽  
Live Coral ◽  
Local Management ◽  
Conservation Actions ◽  
Reef Condition

Over the past few decades, coral reef ecosystems have been lost at accelerated rates as a result of global climate change and local stressors. Local management schemes can help improve the condition of coral reefs by enhancing their ecosystem recovery capacity. Caribbean conservation efforts include mitigation of local anthropogenic stressors, and integrating social participation. Here, we analyzed the case of the Bayahibe reefs in the Southeastern (SE) Dominican Republic to identify conservation actions and illustrate a conceptual example of local seascape management. We assessed reef health indicators from 2011 to 2016. Overall, our results show increases in total fish biomass, in both commercial and herbivorous fishes. Mean live coral cover was 31% and fleshy macroalgae was 23% after multiple disturbances such as Hurricanes Sandy and Isaac (2012), Mathew (2016) and heat stress presented in the study area in 2015. We also described actions taken by stakeholders and government institutions, including the implementation of a policy declaring an area of 869,000 ha as a marine protected area (MPA), enhanced water quality treatment, local restrictions to vessel traffic, enforcement of fishing regulations, and the removal of invasive lionfish (Pterois spp.). In addition, a restoration program for the threatened staghorn coral (Acropora cervicornis) was established in 2011, and currently has eight coral nurseries and six outplanting sites. Considering the biology and ecology of these reefs, we observed good results for these indicators (live coral cover, fish biomass, and water quality) in contrast with severely degraded Caribbean reefs, suggesting that optimizing local management may be a useful example for improving reef condition. Our results provide an overview of trends in reef condition in the SE Dominican Republic and could support current strategies to better protect reefs in the region. Given that Caribbean coral reefs face extreme challenges from global climate change, management measures may improve reef conditions across the region but stronger policy processes and increased scientific knowledge are needed for the successful management of coral reefs.

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