A Positive Trajectory for Corals at Little Cayman Island

Abstract

Coral reefs are damaged by natural disturbances and local and global anthropogenic stresses. As stresses intensify, so do debates about whether reefs will recover after significant damage. True headway in this debate requires documented temporal trajectories for coral assemblages subjected to various combinations of stresses; therefore, we report relevant changes in coral assemblages at Little Cayman Island. Between 1999 and 2012, spatiotemporal patterns in cover, densities of juveniles and size structure of assemblages were documented inside and outside marine protected areas using transects, quadrats and measurements of maximum diameters. Over five years, bleaching and disease caused live cover to decrease from 26% to 14%, with full recovery seven years later. Juvenile densities varied, reaching a maximum in 2010. Both patterns were consistent within and outside protected areas. In addition, dominant coral species persisted within and outside protected areas although their size frequency distributions varied temporally and spatially. The health of the coral assemblage and the similarity of responses across levels of protection suggested that negligible anthropogenic disturbance at the local scale was a key factor underlying the observed resilience.

Baseline Levels of <i>Siderastrea siderea</i> Bleaching under Normal Environmental Conditions in Little Cayman

“…SSTs in 2016 stayed below the typical summertime maximum, which will hopefully promote further recovery of the remaining one third of the stressed colonies to pre-disturbance health. Manfrino et al [18] recorded similar S. siderea bleaching resistance during the 2005 and 2010 bleaching events in Little Cayman. The hardiness of S. siderea leads to survival following certain elevated temperature anomalies which may, in turn, lead to a future phase shift from other dominant reef building corals to S. siderea [19], as many of these other species are more susceptible to bleaching and mortality when exposed to non-ideal conditions [20].…”

Herbivory and the resilience of Caribbean coral reefs: knowledge gaps and implications for management

“…Healthy herbivore populations may be an important factor leading to resilience by preventing the establishment and proliferation of algae following disturbances. While many Caribbean reefs have failed to recover from recent disturbances (but see Manfrino et al 2013), reefs in the Indo-Pacific often recover rapidly from acute pulse disturbances (Connell 1997, Sheppard et al 2008, Adjeroud et al 2009, Gilmour et al 2013, indicating a high level of resilience that is often linked to robust herbivore populations.…”

Demographics and Population Dynamics Project the Future of Hard Coral Assemblages in Little Cayman

“…Previous studies have estimated coral recruitment in Little Cayman by counting colonies that are ≤2 cm in diameter [4], the equivalent of SC1 in this study.…”

“…Live coral cover in Little Cayman has rebounded from its low point of 14% in 2004 to an average of 25%, among the highest in the Caribbean, despite sharing a similar disturbance history with reefs region wide [1] [3] [4]. Little Cayman corals experienced elevated temperature-induced bleaching and mortalities of various intensities during 1987,1995,1998,2003,2005,2009, and 2015.…”