| Summary: | The Kimberley Marine Region is a vast stretch of complex eastern Indian Ocean seascape
spanning approximately six degrees of latitude and eight degrees of longitude. The region includes various
habitats, including offshore reef and shoal systems, and a complex array of nearshore platform and
fringing reefs along an estimated 12,000 km of the northern Western Australian coastline. Isolated from
urban centres, the Kimberley features one of the world’s least anthropogenically impacted tropical reef
ecosystems and is predicted to be a signifcant repository for coral biodiversity. However, little information
has been publicly available to verify this. Here we report a revision of the zooxanthellate coral biodiversity
of the Kimberley region based on new specimen records. Replicate belt transects were surveyed at 135
intertidal and subtidal stations spanning the inshore, mid-shelf and offshore Kimberley from 2009–2014.
Nineteen thousand and eighty-six colonies and 333 species were counted and identifed on the belt
transects, and an additional 62 species were recorded incidentally off transects. Combining the new
museum-accessioned specimen records with recent specimen donations and published historical records
from 1893 onwards resulted in an updated regional diversity estimate of 438 species of zooxanthellate
reef-building corals in the Kimberley. This dataset extends the known distribution range of 85 species,
37 of which represent new records for Australia. Our results show that the Kimberley coral communities
are heterogenous, with pronounced cross-shelf, depth, and subregional diversity patterns. Ashmore
Reef, Cassini Island and Montgomery Reef are regional coral biodiversity hotspots. Goniastrea retiformis,
Porites lutea, Dipsastraea pallida, Goniastrea favulus and Coelastrea aspera dominate the intertidal reef
zones, whilst Porites lichen, Heliopora coerulea, Seriatopora hystrix, Goniastrea pectinata and Montipora
aequituberculata dominate the subtidal reefs. This dataset suggests that the origins, biogeography, and
connectivity within the Australasian region and the diversity of corals in the eastern Indian Ocean have
been misinterpreted in the past. Overall, this study provides a revision of biodiversity and biogeographic
patterns in Australia and highlights the importance of the Kimberley region as a nationally signifcant
reservoir of tropical coral biodiversity with vital, yet under-studied, connections to the Indo-Australian
Centre of Diversity.
|
|---|