Denis et al. 2019

scientific chapter |


Denis V, Soto D, Palmas S, Lin YTV, Benayahu Y, Huang YM, Liu SL, Chen JW, Chen Q, Sturaro N, Ho MJ, Su Y, Dai CF, Chen CA


Taiwan straddles tropical and subtropical latitudes in the North Pacific Ocean. While shallow-water coral reefs in Taiwan have been studied for many years, mesophotic coral ecosystems (MCEs) have recently enjoyed a surge of interest because they are hypothesized to provide a refuge for some reef species in distress. The distribution of MCEs in Taiwan is influenced by numerous biophysical and environmental variables including substrate availability, temperature, light irradiance, and sedimentation. In 1991, an early survey of the diversity of MCEs off Taiwan’s southern coast highlighted sedimentation and the lack of suitable substrates as important factors restricting reef communities at depths below 30 m. The steeply sloping east coast of Taiwan supports well-developed and more accessible MCEs and has therefore been the focus of recent research. Preliminary surveys have documented 18 macroalgal, 95 scleractinian, 33 octocoral, 2 antipatharian, 14 sponge, and 76 fish species. With the exception of a few scleractinians recorded for the first time and possibly restricted to mesophotic waters, the majority of species have a wide bathymetric distribution in Taiwan. However, low-light conditions at mesophotic depths in the north restrict the distribution of photosynthetic organisms to shallow waters. Only one zooxanthellate scleractinian species was found at depths below 40 m where benthic communities are dominated by fan- and whip- shaped octocorals. Historically, MCEs have received little research interest in Taiwan, and most current research is focused on descriptive studies. Future research should examine the ecological importance of these habitats and the roles they play in reef survival.