1 Biogeosciences 2 Research Paper 3 4 Baseline for ostracod-based northwestern Pacific and Indo-Pacific shallow- 5 marine paleoenvironmental reconstructions: ecological modeling of species 6 distributions 7 8 Yuanyuan Hong1,2,*, Moriaki Yasuhara1,2,*, Hokuto Iwatani1,2, Briony Mamo1,2 9 10 11 1School of Biological Sciences, The University of Hong Kong, Pok Fu Lam Road, 12 Hong Kong SAR, China 13 2Swire Institute of Marine Science, The University of Hong Kong, Cape d’Aguilar 14 Road, Shek O, Hong Kong SAR, China 15 16 *Corresponding authors: Hong, Y.Y. (
[email protected]); Yasuhara, M. 17 (
[email protected]). 18 19 20 21 22 23 24 25 1 26 27 28 Abstract: 29 Fossil ostracods have been widely used for Quaternary paleoenvironmental 30 reconstructions especially in marginal marine environments (e.g. for water depth, 31 temperature, salinity, oxygen levels, pollution). But our knowledge of indicator 32 species autoecology, the base of paleoenvironmental reconstructions, remains limited 33 and commonly lacks robust statistical support and comprehensive comparison with 34 environmental data. We analysed marginal marine ostracod taxa at 52 sites in Hong 35 Kong for which comprehensive environmental data are available. We applied linear 36 regression models to reveal relationships between species distribution and 37 environmental factors for 18 common taxa (mainly species, a few genera) in our 38 Hong Kong dataset, and identified indicator species of environmental parameters. For 39 example, Sinocytheridea impressa, widely distributed euryhaline species throughout 40 the East and South China Seas and the Indo-Pacific, indicates eutrophication and 41 botttom-water hypoxia. Neomonoceratina delicata, widely known species from 42 nearshore and estuarine environments in the East and South China Seas, and the Indo- 43 Pacific, indicates heavy-metal pollution and increased turbidity.