Colony size frequency distribution across gradients of reef health in disturbed coral reefs in Northeast Peninsular Malaysia

Abstract

Coral reefs globally are experiencing chronic stress leading to the deterioration of health and functionality. Analysis of size frequency distribution (SFD) of hard corals enables post hoc assessments of major demographic events (e.g., recruitment and mortality) that follow ecological disturbances. Here, we present an evaluation of current reef health, SFD and recruitment of 37 morpho-taxa in Northeast Peninsular Malaysia. Results highlight stress viable demographic structure of massive taxa (e.g., massive Porites) and significant differences of SFD across gradients of reef health, whereby degraded sites were predominantly characterized by negatively skewed (e.g., large colonies) and leptokurtic (e.g., high population turnover) distribution of dominant hard coral taxa. Ultimately, results suggest that locally coral reef degradation can exceed tipping points, after which annual monsoon conditions and degraded reef substrates interact to reinforce and manifest negative feedback loops, thereby impeding demographic recovery, and altering coral SFD and population assemblage.