Data from: Response of subtropical submarine-cave ecosystem to Holocene cave development and Asian monsoon variability

A submarine cave is a unique environment that is dark, food limited,
semi-isolated from the outside, and sheltered from wave action. However,
our knowledge of the long-term change in submarine-cave ecosystems remains
limited. We document here the community-scale responses toward long-term
change in a submarine cave, Daidokutsu in Okinawa in southern Japan. Using
both metazoans (ostracods and bivalves) and protozoans (larger benthic
foraminiferans) in two sediment cores obtained from the cave, we
reconstruct the faunal and diversity changes of the past 7 Kyr. All
taxonomic groups showed long-term, gradual linear change of faunal
composition from predominantly open-water taxa to predominantly cave taxa,
and ostracods showed short-term variability of species diversity. The
long-term faunal trend probably reflects gradual isolation of the cave
ecosystem due to coral reef development (i.e., development of the cave
ceiling) during periods of the Holocene transgression and subsequent
sea-level highstand. The short-term diversity changes show substantial
similarity to centennial- to millennial-scale Holocene Asian monsoon
variability. Ostracod species diversity peaks tend to correspond with
periods of strong East Asian winter monsoons. The results indicate that
limestone submarine-cave ecosystems, an important cryptic habitat,
developed gradually during the Holocene and may be sensitive to rapid
climate changes