Recruitment, growth and mortality of juvenile corals at Eilat, northern Red Sea

Abstract

Rates of recruitment, growth and survival during the early life stages of stony corals may strongly impact community structure on tropical reefs, yet sparse information is available on these processes. We assessed juvenile coral dynamics on coral reefs near Eilat, northern Red Sea. Rates of recruitment among stony-coral genera were similar at sites in close proximity (<200 m), but not at a more distant site (2 km), which differed in substratum type and reef morphology. We observed 42 to 173 juvenile coral colonies m -2 of reef substratum, a much higher abundance than previously reported from reefs in the Caribbean Sea, but potentially similar to abundance on other Indo-Pacific reefs that are known to have higher coral recruitment than Caribbean reefs. Growth rates of juvenile corals were similar among sites and genera, but varied significantly with season. Juvenile mortality varied significantly among reef sites in some coral genera, and was particularly high for individuals of Stylophora spp., weedy corals that also had high rates of recruitment of juveniles, and thus rapid population turnover. Growth and mortality rates of corals at these sites were within values recorded for other reef locations worldwide. We conclude that on shallow reefs in the northern Red Sea, rela- tive abundances of juvenile coral genera depend mainly on variation in their recruitment patterns, and do not vary significantly with rates of juvenile growth or mortality.