Modern Distribution of Arctic Ocean Ostracodes: Implications for Applications to Paleoceanographic Reconstructions

Ostracodes are micro-crustaceans with calcareous bivalved shells whose shell chemistry (Mg/Ca ratios) and species ecology make them useful in paleoceanography. They are particularly common in shallow and deep-water sediments in the Arctic Ocean where they are used to reconstruct bottom water temperature, salinity, sea ice, nutrient productivity, ice-rafting, and other parameters during the last 40 ka. To improve our understanding of ostracodes as Arctic paleoceanographic proxies, we analyzed the distribution of 103 modern species in nearly 600 surface sediment samples, expanding on studies initiated in the 1990s (ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/cronin1995/). This database includes the latitude, longitude, water depth, and bottom water temperatures for each sample and includes materials from the Arctic abyssal plains, major ridges and plateaus, continental shelves of the Kara, Laptev, East Siberian, Chukchi, and Beaufort Seas and several subarctic regions (e.g. Bering Sea, North Atlantic). Our studies show that in the Arctic Ocean, the distribution of ostracode species is controlled by bottom water temperature, salinity, food availability, and sea-ice coverage, which are important information for use in paleoceanographic reconstructions. We will discuss the modern distribution of the following key podocopid genera: Henryhowella, Krithe, Pseudocythere, Acetabulastoma, and Cytheropteron together with the myodocopid genus Polycope.