Peering into the Benthic Cosmos and the Canyon’s Past
Like the land above sea level, the ocean floor represents a mosaic of
environments. Benthic ecosystems cover virtually limitless combinations of
physical, chemical, and biological conditions.
The ROV Ventana made its first general seafloor survey in August 1988. Since then researchers have used such inspections to assess population patterns of sea stars, crabs, sea cucumbers, tunicates, clams, and other ocean-bottom residents.
Since 1994 institute ecologists have regularly surveyed 100-meter-long (330-foot-long) transects, using video images to track the diversity and abundance of animals. By comparing the accumulated information from year to year and site to site, they gain a better understanding of rates of population change for some common benthic invertebrates.
Investigating cold seeps with Ventana about 50 kilometers (31 miles) offshore, institute scientists have discovered vigorous colonies of vesicomyid clams and grayish-white bacterial mats. They also collected limestone crusts and "chimneys." These tantalizing findings presented a chance to pursue MBARI’s broad goal of understanding bay systems by closely examining one aspect of the bay: cold-seep communities and the geologic conditions that give rise to them.
Questions on the plumbing system beneath the bay have prompted technological innovations at MBARI to improve the gathering of geological information. Underwater saws and a rock hammer hew chunks of rock from geological features of interest. For collecting soft sediments, institute researchers and engineers developed a series of push-corers. The benthic barrel gauges the flow rates of cold-seep fluids. Using a diamond-drill coring system developed at MBARI, researchers have collected cores of granite from canyon walls.
As the institute flexes new muscles with powerful ocean hardware that allows penetration not only of Monterey Bay’s greatest depths but also distant waters, unanticipated opportunities will surely arise from the benthic cosmos.
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