title: Effects of simulated eutrophication and overfishing on algae and invertebrate settlement in a coral reef of Koh Phangan, Gulf of Thailand.
abstract: Coral reefs in the Gulf of Thailand are highly under-investigated regarding responses to anthropogenic stressors. Thus, this study simulated overfishing and eutrophication using herbivore exclosure cages and slow-release fertilizer to study the in-situ effects on benthic algae and invertebrate settlement in a coral reef of Koh Phangan, Thailand. Settlement of organisms and the development of organic matter on light-exposed and shaded tiles were quantified weekly/biweekly over a study period of 12 weeks. Simulated eutrophication did not significantly influence response parameters, while simulated overfishing positively affected dry mass, turf algae height and fleshy macroalgae occurrence on light-exposed tiles. On shaded tiles, settlement of crustose coralline algae decreased, while abundances of ascidians increased compared to controls. An interactive effect of both stressors was not observed. These results hint to herbivory as actual key controlling factor on the benthic community, and fleshy macroalgae together with ascidians as potential bioindicators for local overfishing.
authors: Leibniz Center for Tropical Marine Ecology (ZMT), Fahrenheitstrasse 6, 28369 Bremen, Germany. Electronic address: ines.stuhldreier@zmt-bremen.de.
authors: Ines
authors: I
authors: Stuhldreier
authors: Faculty of Biology and Chemistry, University of Bremen, P.O. Box 330440, 28334 Bremen, Germany. Electronic address: pepe_bastian@hotmail.com.
authors: Pepe
authors: P
authors: Bastian
authors: Center for Oceanic Research and Education (COREsea), Chaloklum, Koh Phangan, 84280 Surat Thani, Thailand. Electronic address: eike@coresea.com.
authors: Eike
authors: E
authors: Schönig
authors: Leibniz Center for Tropical Marine Ecology (ZMT), Fahrenheitstrasse 6, 28369 Bremen, Germany; Faculty of Biology and Chemistry, University of Bremen, P.O. Box 330440, 28334 Bremen, Germany. Electronic address: christian.wild@zmt-bremen.de.
authors: Christian
authors: C
authors: Wild
mesh_terms: D000818:Animals; D057894:Coral Reefs; D017753:Ecosystem; D005068:Eutrophication; D005308:Fertilizers; D060434:Herbivory; D007448:Invertebrates / Q000502:physiology*; D012624:Seaweed / Q000502:physiology*; D013785:Thailand
chemical_list: D005308:Fertilizers
keywords: Bottom-up; Eutrophication; Gulf of Thailand; Overfishing; Top-down