[en] 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.
