Title: EVIDENCE OF REPRODUCTIVE PLASTICITY OF PORITES ASTREOIDES ACROSS A DEPTH GRADIENT IN BERMUDA

Abstract: Mesophotic coral reef ecosystems (MCEs) extend to the bottom of the photic zone and are relatively sheltered from anthropogenic and natural disturbances resulting in low reef degradation compared to shallow reef counterparts. MCEs are hypothesized to serve as a refuge for shallow reefs, where larvae may aid the re-population of previously disturbed shallow habitats. This study determines whether upper mesophotic Porites astreoides can function as a reproductive refuge for shallow reef environments by (1) comparing patterns in lunar periodicity, fecundity, and differences in larval sizes between 10 m and 30 m colonies, and (2) testing whether there is a significant difference between larval settlement success in laboratory settings in July and August 2015. Shallow colonies released more larvae than upper mesophotic colonies in July, while the opposite pattern was observed in August. In August, the shallow colonies released significantly larger larvae than the upper mesophotic colonies, however this did not hinder metamorphosis as larval settlement rates did not differ with parental depth. These results indicate that upper mesophotic P. astreoides produce viable larvae that are able to colonize available substrates at similar rates to shallow larvae. In conjunction with vertical connectivity studies, our results suggest that upper mesophotic P. astreoides may be able to serve as a reproductive refuge for shallow water environments.

Authors: Wong KH, Reich HG, Goodbody-Gringley G

Presentation: Poster (#183)

Session: 15

Date: 06/21/16

Time: 18:15 - 19:45

Location: Poster/Exhibit Hall

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