Oxygen minimum zone biotic baseline transects for paleoceanographic reconstructions in Santa Barbara Basin, CA

Autor: James P. Kennett, Sarah E. Myhre, Tessa M. Hill, Curtis Deutsch, M. J. Borreggine, Dorothy K. Pak, Craig Nicholson
Rok vydání: 2018
Předmět:
Zdroj: Deep Sea Research Part II: Topical Studies in Oceanography. 150:118-131
ISSN: 0967-0645
DOI: 10.1016/j.dsr2.2017.12.009
Popis: We describe modern ocean floor biological trends employing exploratory Remotely Operated Vehicle (ROV) Hercules dives in the Santa Barbara Basin, California, USA, through the Nautilus Exploration Program. Using ROV videos, in situ measurements, and sediment cores, we described oxygenation, temperature, biological zonation, and bulk sediment δ15N across three 120-meter vertical transects (from 380 to 500 m, m) that cross the depth of the ventilating sill (475 m) and upper OMZ boundary. These observations revealed major changes in the distribution of biota tied largely to changes in dissolved oxygen concentration. Upward increases in oxygen and temperature were coincident with successive disappearance and appearance of megafauna and foraminifera species and overall increases in community diversity. The most significant and abrupt change in seawater measurements, biological communities, sediment textures, and nitrogen isotopes were observed near the depth of the ventilating sill (from 480 to 450 m). Microbial mats were observed up to the depth of 475 m. Dense populations of Alia permodesta were identified at depths where dissolved oxygen ([O2]) was
Databáze: OpenAIRE
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