Cramer KL et al. (2020), Widespread loss of Caribbean acroporid corals w...

ECB-ART-49824

Sci Adv 2020 Apr 01;617:eaax9395. doi: 10.1126/sciadv.aax9395.

Show Gene links Show Anatomy links

Widespread loss of Caribbean acroporid corals was underway before coral bleaching and disease outbreaks.

Cramer KL , Jackson JBC , Donovan MK , Greenstein BJ , Korpanty CA , Cook GM , Pandolfi JM .

Abstract
The mass mortality of acroporid corals has transformed Caribbean reefs from coral- to macroalgal-dominated habitats since systematic monitoring began in the 1970s. Declines have been attributed to overfishing, pollution, sea urchin and coral disease, and climate change, but the mechanisms are unresolved due to the dearth of pre-1970s data. We used paleoecological, historical, and survey data to track Acropora presence and dominance throughout the Caribbean from the prehuman period to present. Declines in dominance from prehuman values first occurred in the 1950s for Acropora palmata and the 1960s for Acropora cervicornis, decades before outbreaks of acroporid disease or bleaching. We compared trends in Acropora dominance since 1950 to potential regional and local drivers. Human population negatively affected and consumption of fertilizer for agriculture positively affected A. palmata dominance, the latter likely due to lower human presence in agricultural areas. The earlier, local roots of Caribbean Acropora declines highlight the urgency of mitigating local human impacts.

PubMed ID: 32426458
PMC ID: PMC7176417
Article link: Sci Adv
Grant support: [+]

Article Images: [+] show captions

References [+] :

Alvarez-Filip, Flattening of Caribbean coral reefs: region-wide declines in architectural complexity. 2009, Pubmed, Echinobase

	Fig. 1. Distribution of dominance and presence/absence data for acroporid corals.Data from reef crest zones in magenta; data from midslope zones in blue. Size of dot proportional to total number of surveys across both reef zones and all bins combined (range, 1 to 541).
	Fig. 2. Long-term trends in presence and dominance of Caribbean acroporid corals.Proportion of reef sites with species present (gray) and dominant (black), determined from a binomial GLMM that included country as a random effect. Vertical bars are standard errors of mean-fitted values; stars indicate earliest significant declines since the historical period compared with Pleistocene values; numbers are reef sites with species presence/absence data for each time bin. Arrows indicate first recorded occurrence of major novel disturbances, with timing of coral bleaching signifying bleaching at several locations across the Caribbean. Diadema, mass die-off of sea urchin D. antillarum.
	Fig. 3. Significant drivers of change in dominance of A. palmata at the reef crest zone from 1950 to 2011.(A) Effect of human population density. (B) Effect of fertilizer consumption. Partial effects determined from a binomial generalized linear mixed effects model that included time bin and country as random effects. Fixed effects were log transformed to reduce the influence of extreme large values and improve model convergence. Blue bands represent 95% confidence intervals.