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PeerJ
2019 Jan 01;7:e7589. doi: 10.7717/peerj.7589.
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Sargassum blooms in the Caribbean alter the trophic structure of the sea urchin Diadema antillarum.
Cabanillas-Terán N
,
Hernández-Arana HA
,
Ruiz-Zárate MÁ
,
Vega-Zepeda A
,
Sanchez-Gonzalez A
.
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The arrival of large masses of drifting Sargassum since 2011 has caused changes in the natural dynamics of Caribbean coastal ecosystems. In the summer of 2015, unprecedented and massive mats of S. fluitans and S. natans have been observed throughout the Mexican Caribbean including exceptional accumulations ashore. This study uses stable isotopes to assess the impact of Sargassum blooms on the trophic dynamics of the Diadema antillarum sea urchin, a keystone herbivore on many Caribbean reefs. Bayesian models were used to estimate the variations in the relative proportions of carbon and nitrogen of assimilated algal resources. At three lagoon reef sites, the niche breadth of D. antillarum was analysed and compared under massive influx of drifting Sargassum spp. vs. no influx of Sargassum blooms. The effects of the leachates generated by the decomposition of Sargassum led to hypoxic conditions on these reefs and reduced the taxonomic diversity of macroalgal food sources available to D. antillarum. Our trophic data support the hypothesis that processes of assimilation of carbon and nitrogen were modified under Sargassum effect. Isotopic signatures of macroalgae associated with the reef sites exhibited significantly lower values of δ15N altering the natural herbivory of D. antillarum. The Stable Isotopes Analysis in R (SIAR) indicated that, under the influence of Sargassum blooms, certain algal resources (Dictyota, Halimeda and Udotea) were more assimilated due to a reduction in available algal resources. Despite being an abundant available resource, pelagic Sargassum was a negligible contributor to sea urchin diet. The Stable Isotope Bayesian Ellipses in R (SIBER) analysis displayed differences between sites, and suggests a reduction in trophic niche breadth, particularly in a protected reef lagoon. Our findings reveal that Sargassum blooms caused changes in trophic characteristics of D. antillarum with a negative impact by hypoxic conditions. These dynamics, coupled with the increase in organic matter in an oligotrophic system could lead to reduce coral reef ecosystem function.
Figure 1. Study sites.Study area and sampling localities at the south coast of Quintana Roo: Mahahual (A), Xahuayxol (B) and Xcalak (C). The green polygon represents the marine protected area Parque Nacional Arrecifes de Xcalak (PNAX). Figure credit: Alejandro A. Aragón-Moreno.
Figure 2. Lagoon reef-scape showing the sections with Sargassum blooms.Lagoon reef-scape showing the sections: a: decomposing Sargassum spp., Section b, leachates (dark brown water) and section c, back reef, areas without visible leachates. Based on van Tussenbroek et al. (2017).
Figure 4. Algal resources proportions consumed by Diadema antillarum.Contribution rates of algae to the diet of Diadema antillarum in the two scenarios (WSE and USE). Results are shown as 25% (light error bars), 75% (grey error bars) and 95% (dark error bars) of credibility intervals. (A) Represents the contribution for D. antillarum at Mahahual without Sargassum effect (WSE), (B) represents D. antillarum at Mahahual under Sargassum effect (USE); (C) represents D. antillarum in Xahuayxol WSE, (D) represents D. antillarum in Xahuayxol USE; (E) represents D. antillarum in Xcalak WSE and (F) represents D. antillarum in Xcalak USE. Bloom turf is the Sargassum’s associated turf. The blue bar represents the pelagic sources USE.
Figure 5. Isotope niche breadth of the sea urchin Diadema antillarum.Isotope niche breadth of the sea urchin Diadema antillarum at Mahahual (A), Xahuayxol (B) and Xcalak (C). Dotted lines are without Sargassum effect (WSE) and solid lines under Sargassum effect (USE).
Arellano-Verdejo,
ERISNet: deep neural network for Sargassum detection along the coastline of the Mexican Caribbean.
2019, Pubmed
Arellano-Verdejo,
ERISNet: deep neural network for Sargassum detection along the coastline of the Mexican Caribbean.
2019,
Pubmed
Arias-González,
A coral-algal phase shift in Mesoamerica not driven by changes in herbivorous fish abundance.
2017,
Pubmed
Bauman,
Tropical harmful algal blooms: an emerging threat to coral reef communities?
2010,
Pubmed
Behmer,
Coexisting generalist herbivores occupy unique nutritional feeding niches.
2008,
Pubmed
Ben-David,
Mixing models in analyses of diet using multiple stable isotopes: a response.
2001,
Pubmed
Cabanillas-Terán,
Trophic ecology of sea urchins in coral-rocky reef systems, Ecuador.
2016,
Pubmed
,
Echinobase
Camacho-Cruz,
Water quality in the eastern karst region of the Yucatan Peninsula: nutrients and stable nitrogen isotopes in turtle grass, Thalassia testudinum.
2020,
Pubmed
Cramer,
Anthropogenic mortality on coral reefs in Caribbean Panama predates coral disease and bleaching.
2012,
Pubmed
Hobson,
Tracing origins and migration of wildlife using stable isotopes: a review.
1999,
Pubmed
Hughes,
Catastrophes, phase shifts, and large-scale degradation of a Caribbean coral reef.
1994,
Pubmed
Jackson,
Comparing isotopic niche widths among and within communities: SIBER - Stable Isotope Bayesian Ellipses in R.
2011,
Pubmed
Lapointe,
Land-based nutrient enrichment of the Buccoo Reef Complex and fringing coral reefs of Tobago, West Indies.
2010,
Pubmed
Layman,
Can stable isotope ratios provide for community-wide measures of trophic structure?
2007,
Pubmed
Layman,
Niche width collapse in a resilient top predator following ecosystem fragmentation.
2007,
Pubmed
Layman,
Applying stable isotopes to examine food-web structure: an overview of analytical tools.
2012,
Pubmed
Moore,
Incorporating uncertainty and prior information into stable isotope mixing models.
2008,
Pubmed
Morillo-Velarde,
Habitat degradation alters trophic pathways but not food chain length on shallow Caribbean coral reefs.
2018,
Pubmed
Parnell,
Source partitioning using stable isotopes: coping with too much variation.
2010,
Pubmed
Phillips,
Source partitioning using stable isotopes: coping with too many sources.
2003,
Pubmed
Phillips,
Incorporating concentration dependence in stable isotope mixing models.
2002,
Pubmed
Post,
Getting to the fat of the matter: models, methods and assumptions for dealing with lipids in stable isotope analyses.
2007,
Pubmed
Risk,
The use of delta(15)N in assessing sewage stress on coral reefs.
2009,
Pubmed
Rodríguez-Barreras,
Understanding trophic relationships among Caribbean sea urchins.
2016,
Pubmed
,
Echinobase
Rodríguez-Martínez,
Faunal mortality associated with massive beaching and decomposition of pelagic Sargassum.
2019,
Pubmed
Smetacek,
Green and golden seaweed tides on the rise.
2013,
Pubmed
Sweatman,
Habitat fragmentation has some impacts on aspects of ecosystem functioning in a sub-tropical seagrass bed.
2017,
Pubmed
Wang,
The great Atlantic Sargassum belt.
2019,
Pubmed
Weil,
Population characteristics of the sea urchin Diadema antillarum in La Parguera, Puerto Rico, 17 years after the mass mortality event.
2005,
Pubmed
,
Echinobase
van Tussenbroek,
Severe impacts of brown tides caused by Sargassum spp. on near-shore Caribbean seagrass communities.
2017,
Pubmed