Reef corals are declining worldwide due to local stressors and global climate change but the ways these different factors interact to reduce coral abundance remain obscure. We analyzed data from more than 35,000 surveys to document ecological changes on reefs throughout the wider Caribbean from 1970 to 2012, and then compared local differences in the status and trends of coral populations in relation to local differences in fishing pressure, human population density, and thermal stress. Average coral cover declined by half by 1990 with little subsequent decline, while macroalgal cover increased more than three fold in the 1980s and early 1990s and has remained high. These early losses were principally due to outbreaks of disease and overfishing a decade before the first regional episodes of sustained thermal stress and coral bleaching. In contrast, more recent losses of corals following extreme thermal stress varied among locations as a function of fishing pressure, the abundance of macroalgae, and concomitant susceptibility to disease. These differences are strongly related to basic socioeconomic indicators with quality of governance, GDP, and fishing regulations the most important factors. Our results support the hypothesis that local protections can increase reef resilience in the short term pending global action on climate change.


Jackson, J., Scripps Institution of Oceanography, USA, jeremybcjackson@gmail.com


Oral presentation

Session #:65
Date: 06/23/2016
Time: 15:15
Location: 305 A/B

Presentation is given by student: No