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Curious about what lurks and flourishes in the deep canyon right off our coast?
Check out this rare underwater video footage of the La Jolla submarine canyon, taken on March 26, 2013, as part of a California Sea Grant project to understand how small marine creatures respond to the watery world around them.
The video was shot from a remotely operated vehicle (ROV) that can probe depths beyond the reach of divers.
The first clip shows video from the ROV as it explores a cliff overhanging part of the canyon wall, where squid (aka 'calamari') have deposited their little mop-like clusters of white egg capsules.
In the second clip, we descend to depths of about 300 feet, where colorful sea fans and sponges dot the cold, dark landscape.
The white flakes swirling around are collectively part of the "marine snow" and are made up of pieces of dead zooplankton, clumps of algae, fecal material and other debris that feeds the canyon's animals.
"There are a lot of hungry mouths waiting for that material to come down," explained CA Sea Grant Trainee Michael Navarro.
Scripps Institution of Oceanography biologist Ed Parnell and Navarro are videoing ocean life off San Diego on a monthly basis right now to watch how animals such as squid, crabs, shrimp and sea stars respond to changes in ocean water temperatures, salinity and dissolved oxygen levels.
"We've seen crabs move 60 feet vertically in the water column in a month," Navarro, a Scripps graduate student, said. "We've also seen a carpet of sea stars moving together in a huge group. We are seeing animals move a lot more than we expected. We don't know why."
In coming months, they hope to find answers.
Below is a technical summary of their project, published in the 2013 Program Directory.
Consequences of Nearshore Low Oxygen and Low pH for Coastal Resources of Southern California
Feb. 2012–Jan. 2014
Lisa Levin, UCSD/SIO, 858.534.3579, llevin@ucsd.edu
Ed Parnell, UCSD/SIO, 858.822.2701, eparnell@ucsd.edu
Todd Martz, UCSD/SIO, 858.534.7466, trmartz@ucsd.edu
In this project, researchers are investigating the combined effects of low-oxygen, low-pH conditions on marine organisms living at depths between 20 meters and 300 meters off San Diego. Specific goals include mapping dissolved oxygen concentrations and water acidity to characterize the frequency, duration, extent and intensity of these conditions on seasonal and, if possible, weekly time scales. Maps of oxygen concentrations will be superimposed on squid egg-bed habitat maps to identify areas where the species may be susceptible to low-oxygen stress, particularly during its early life history stages. Through laboratory experiments and field collecting, researchers will estimate critical lethal and sublethal oxygen and pH thresholds for the market squid. These thresholds will be used, in conjunction with monitoring data, to identify areas where squid embryos may experience higher than normal mortalities. This work will address the hypothesis that market squid migrate or shift spawning grounds in response to dissolved oxygen concentrations. Results will provide valuable insights into the potential consequences of the shoaling of the oxygen minimum zone in the Southern California Bight on key marine resources with the California Current large marine ecosystem.
Written by Christina S. Johnson