Baseline for ostracod-based northwestern Pacific and Indo-Pacific shallow-marine paleoenvironmental reconstructions: ecological modeling of species distributions

Abstract

Abstract. Fossil ostracods have been widely used for Quaternary paleoenvironmental reconstructions, especially in marginal marine environments (e.g., for water depth, temperature, salinity, oxygen levels, pollution). But our knowledge of indicator species autoecology, the base of paleoenvironmental reconstructions, remains limited and commonly lacks robust statistical support and comprehensive comparison with environmental data. We analyzed marginal marine ostracod taxa at 52 sites in Hong Kong for which comprehensive environmental data are available. We applied linear regression models to reveal relationships between species distribution and environmental factors for 18 common taxa (mainly species, a few genera) in our Hong Kong dataset and identified indicator species of environmental parameters. For example, Sinocytheridea impressa, a widely distributed euryhaline species throughout the East and South China Sea and the Indo-Pacific, indicates eutrophication and bottom-water hypoxia. Neomonoceratina delicata, a widely known species from nearshore and estuarine environments in the East and South China Sea and the Indo-Pacific, indicates heavy metal pollution and increased turbidity. The 18 taxa used for this study are widely distributed geographically and divided into the following groups: widespread (throughout the northwestern Pacific and Indo-Pacific regions), temperate (South China Sea to Russia (Sea of Japan coast) and Japan), subtropical (Indo-Pacific to the East China Sea), tropical (Indo-Pacific and South China Sea), and globally distributed. With statistical support from ecological modeling and comprehensive environmental data, these results provide a robust baseline for ostracod-based Quaternary–Anthropocene paleoenvironmental reconstructions in the tropical–extratropical northwestern Pacific and Indo-Pacific. Highlights. We provide a robust baseline for ostracod-based (microscopic Arthropods) paleoenvironmental reconstructions from Quaternary and Anthropocene marginal marine sediments. The studied species have wide distributions over the tropics and extratropics of the northwestern Pacific and Indo-Pacific. Ecological modeling has established ostracod species as reliable indicators for paleoenvironmental reconstructions.

Early Miocene marine ostracodes from southwestern India: implications for their biogeography and the closure of the Tethyan Seaway

“…No other typical deep-water genera, such as Cytheropteron and Argilloecia, occurred in this sample, even though these genera are known to be abundant in upper bathyal depths in the Indo-Pacific region (Iwatani et al, 2018). In addition to the above-mentioned abundant genera, many other warm (often tropical) water indicator genera occurred in this sample (e.g., Cytherelloidea, Neomonoceratina, Paijenborchellina, Ruggieria, Phlyctenophora, and Stigmatocythere) (Wood and Whatley, 1994;Yasuhara et al, 2018;Hong et al, 2019;Shin et al, 2019). Loxoconcha and Aurila are typical phytal genera, although they include sediment-dwelling species (Kamiya, 1988;Yasuhara et al, 2002bYasuhara et al, , 2005Szczechura, 2006;Yasuhara and Seto, 2006;Reich et al, 2015).…”

Possible predation damage and repair in a Quaternary marine ostracod

“…The assignment to Bicornucythere has continued to be used in many recent studies (e.g. Hong et al ; Irizuki et al ; Yamada et al ). We are considering a full taxonomic review and revision of the generic assignment but this is beyond the scope of the present study.…”

“…Bicornucythere bisanensis is widely distributed in brackish water bodies along the northern coast of Vietnam, the coasts of China and Japan (e.g. Okubo ; Zhao et al ; Zhou et al ; Yasuhara & Irizuki ; Irizuki et al ; Yasuhara & Seto ; Irizuki et al ; Tanaka et al ; Hong et al ; Hong et al ). In the ostracod assemblage from core DK06, sample WT‐08, B. bisanensis was represented abundantly by a suite of adult and juvenile instars, indicative of a low‐energy autochthonous thanatocoenosis (Boomer et al ) with little or no post‐mortem transport or sorting.…”

Calibration of Mg / Ca and Sr / Ca in coastal marine ostracods as proxy of temperature

“…Sinocytheridea impressa and N. delicata are shallow marine ostracods from the superfamily Cytheroidea (Brandão et al, 2020), which are mainly distributed in Asian waters (Hong et al, 2019;Tanaka et al, 2011). The abundance of both species 45 has been used as an indicator of sea level transgressions (Chunlian et al, 2013).…”

“…delicata is common in well-ventilated moderate saline bays (Hong et al, 2019;Irizuki et al, 2005). Paleoenvironmental investigations have focused on the study of assemblages of these two species, but not the elemental composition of their shells as indicator of environmental marine variables, such as temperature or salinity.…”