Experimental Bleaching of a Reef-Building Coral Using a Simplified Recirculating Laboratory Exposure System

Abstract

Determining stressor-response relationships in reef building corals continues to be a critical research need due to global declines in coral reef ecosystems and projected declines for the future. A simplified recirculating coral exposure system was coupled to a solar simulator to allow laboratory testing of a diversity of species and morphologies of reef building corals under ecologically relevant conditions of temperature and solar radiation. Combinations of lamps and attenuating filters allowed for assignment of solar radiation treatments in experimental bleaching studies. Three bleaching experiments were performed using the reef building coral, Pocillopora damicornis, to assess the reproducibility of system performance and coral responses under control and stress conditions. Experiments showed consistent temperature-and solar radiation dependent-changes in pigment, numbers of symbiotic algae, photosystem II quantum yield, and tissue loss during exposure and recovery. The laboratory exposure system is recommended for use in experimental bleaching studies with reef building corals.

Biogeographic variability in the physiological response of the cold‐water coral Lophelia pertusa to ocean acidification

“…Previous cold-water coral physiology studies have utilized both systems, perhaps accounting for some of the variability among studies. Despite evidence that recirculating systems are adequate for housing shallow-water (Barron et al 2010) and deep-sea (Lunden et al 2014a,b) corals, it is plausible that this difference partially accounted for the lower physiological performance observed in the Gulf of Mexico corals, as previous studies have found reduced physiological rates in recirculating systems (e.g. Otoshi et al 2003; but see Tomoda et al 2005).…”

“…Despite evidence that recirculating systems are adequate for housing shallow‐water (Barron et al . ) and deep‐sea (Lunden et al . ,b) corals, it is plausible that this difference partially accounted for the lower physiological performance observed in the Gulf of Mexico corals, as previous studies have found reduced physiological rates in recirculating systems ( e.g .…”