Image courtesy of Ocean Exploration Trust

Sonia Fernandez, UCSB—General animal characteristics of the Santa Barbara Basin deep sea animal communities have been described in previous studies. But thanks to state-of-the-art underwater exploration technology in the form of the ROV Hercules, UC Santa Barbara paleoceanographers Dorothy Pak and James Kennett, geophysicist Craig Nicholson and colleagues at the University of Washington, including lead author Sarah Myrhe, recently got a rare, comprehensive, real-time look at the basin’s ecology. Their resulting paper, “Oxygen minimum zone biotic baseline transects for paleoceanographic reconstructions in Santa Barbara Basin, CA,” appears in the journal Deep-Sea Research II.

Perhaps better known as one of the submersibles used for exploring the wreck of the RMS Titanic under the aegis of explorer and UCSB alumnus Robert Ballard, ROV Hercules was deployed for this project to better understand the influence of upward increasing oxygen in the basin on the distribution of animal and microbial communities on the ocean floor and open water column.

Using a suite of technology on the Hercules, including sensors, cameras, remote-controlled sampling tools and a live feed, the researchers were able, over two dives, to collect sediments, take measurements and observe the distribution and abundance of various organisms that call Santa Barbara Basin their home.

The deepest, most oxygen-poor sections of the transect belonged to the microbes, the tiny snail Alia permodesta and a restricted assemblage of single-celled organisms called foraminifera. There was an almost complete absence of large burrowing benthic animals that reside at shallower basin depths. Hence sediments at these depths remain undisturbed.

Thanks to the sediment coring, researchers also are now able to compare the distribution of modern biological assemblages to those of the past for paleoceanographic reconstructions that reveal climate patterns and ocean oxygen changes over millennia. —Excerpted from UCSB.edu, Author: Sonia Fernandez

Image courtesy of Ocean Exploration Trust