A trophic model of fringing coral reefs in Nanwan Bay, southern Taiwan suggests overfishing

Pi-Jen Liu (1) , Kwang-Tsao Shao (2) , Rong-Quen Jan (2) , Tung-Yung Fan (3) , Saou-Lien Wong (4) , Jiang-Shiou Hwang (5) , Jen-Ping Chen (4) , Chung-Chi Chen (6) , Hsing-Juh Lin (1, 5)

1 Department of Life Sciences
2 Academia Sinica
3 National Museum of Marine Biology and Aquarium
4 Department of Aquaculture
5 National Taiwan Ocean University
6 Department of Life Sciences

Several coral reefs of Nanwan Bay, Taiwan have recently undergone shifts to macroalgal or sea anemone dominance. Thus, a mass-balance trophic model was constructed to analyze the structure and functioning of the food web. The fringing reef model was comprised of 18 compartments, with the highest trophic level of 3.45 for piscivorous fish. Comparative analyses with other reef models demonstrated that Nanwan Bay was similar to reefs with high fishery catches. While coral biomass was not lower, fish biomass was lower than those of reefs with high catches. Consequently, the sums of consumption and respiratory flows and total system throughput were also decreased. The Nanwan Bay model potentially suggests an overfished status in which the mean trophic level of the catch, matter cycling, and trophic transfer efficiency are extremely reduced.

Mots clés: Ecopath; Network analysis; Food web; Phase shift; Macroalgae

Pi-Jen Liu, Kwang-Tsao Shao, Rong-Quen Jan, Tung-Yung Fan, Saou-Lien Wong, et al.. A trophic model of fringing coral reefs in Nanwan Bay, southern Taiwan suggests overfishing. Marine Environmental Research, 2009, 68 (3), pp.106. ⟨10.1016/j.marenvres.2009.04.009⟩. ⟨hal-00563078⟩