PAM Chlorophyll Fluorometry: a New in situ Technique for Stress Assessment in Scleractinian Corals, used to Examine the Effects of Cyanide from Cyanide Fishing

摘要: Sodium cyanide is being used on reefs in the Asia-Pacific region to capture live fish for aquarium industry, and supply a rapidly growing, restaurant-based demand, The effects of reef biota have not been fully explored. To investigate its effect hard corals, we exposed small branch lips Stylophora pistillata Acropora aspera concentrations estimated occur during fishing. Pulse amplitude modulation (PAM) chlorophyll fluorescence techniques were examine photoinhibition photosynthetic electron transport symbiotic algae (zooxanthellae) tissues These measurements made situ real time using recently developed submersible PAM fluorometer. In S. pistillata. exposure resulted an almost complete cessation rate. Both species displayed marked decreases ratio variable (F-v) maximal (F-m) (dark-adapted F-v/F-m), following cyanide, signifying decrease photochemical efficiency. Dark-adapted F-v/F-m recovered normal levels similar 6 d, although intense tissue discolouration, phenomenon well-recognised as coral 'bleaching' was observed this period, Bleaching caused by loss zooxanthellae from tissues, sub-lethal stress response corals. Using technique quenching analysis, corals did show light activation Calvin cycle enzymes high non-photochemical (q(N)), photoprotective dissipation excess heat, features are symptomatic known properties inhibitor cycle. results study that impairment zooxanthellar photosynthesis is; site cyanide-mediated toxicity, cue causes release their zooxanthellac exposure. This demonstrates efficacy PBM fluorometry new tool assessment zooxanthellate scleractinian (C) 1999 Elsevier Science Ltd. All rights reserved.