Researchers deploy a new 13,000-foot mooring off California.
Instruments Now Relaying Vital Info about California’s Ocean Environment
Data range from rising carbon dioxide levels to marine mammal soundsScripps Institution of Oceanography/University of California, San Diego
Nearly 60 years ago scientists at Scripps Institution of Oceanography at UC San Diego helped launch the California Cooperative Oceanic Fisheries Investigations (CalCOFI) program to investigate the inner workings of the seas off California’s coast. With a steady stream of oceanographic surveys conducted over several decades, the CalCOFI program has produced a priceless trove of marine data unlike any other in the world.
Now Scripps scientists are intent on expanding and refining that information—in an effort to decipher new and long-standing environmental threats—with the recent deployment of a new mooring and its suite of ocean-probing instruments.
The mooring, known as “CCE-1” for the California Current Ecosystem, is a 4,000-meter- (13,123-foot) long string of specialized wire, chain, and rope bearing numerous oceanographic instruments. Deployed 250 kilometers (155 miles) southwest of Point Conception, CCE-1 records a broad array of new data, from carbon dioxide to plankton concentrations, ocean currents to marine mammal sounds. Some of the data are transmitted to shore using a satellite telemetry network and all of these measurements are available for public viewing at http://mooring.ucsd.edu/projects/cce/cce_data.html. CCE-1 is the first of three intended moorings in this region.
Scripps scientists Mark Ohman and Uwe Send, the leaders of the project, say such data are urgently needed in light of looming threats such as increasing levels of acid in the oceans.
“There is a higher CO2 content in the surface waters than we have seen in recent years and a lower pH, and the consequences for marine organisms is a pressing open question,” said Ohman, a Scripps professor of biological oceanography.
Ohman said acidified waters have impinged into shallow levels in the California Current system, currents that flow off the state’s coastline and influence a range of the state’s important economic and recreational activities.
“We don’t know the persistence of these events or their areal extent,” said Ohman, who heads the California Current Ecosystem research site, which is part of the National Science Foundation’s Long-Term Ecological Research program. “This is one of the reasons why we think getting moorings in sooner rather than later is a pressing topic. Moorings give us a new window on the physically driven forces that can push the ecosystem—especially the living components —in different directions.”
Send, a professor of physical oceanography and a mooring specialist, led the team that designed, constructed, and deployed the new mooring and maintains the associated website. CCE-1 delivers information about a mix of processes such as ocean and atmosphere interplay, physical characteristics such as temperature levels and seawater density, and biological and chemical fluctuations. He says the mooring’s measurements will provide data relevant to climate studies as well as fishery management.
“I am hoping that the mooring allows us to observe and understand events and changes as they happen so that we can try to tie them together,” said Send.
The mooring is situated along a sampling transect known as “line 80,” a strategic location with a reputation borne from CalCOFI surveys for a wide range of oceanographic conditions. This line is also regularly visited by Spray ocean gliders from Scripps to measure oceanographic properties over a broad geographic area.
In addition to Ohman and Send, participants in the mooring project include Chris Sabine of the National Oceanic and Atmospheric Administration’s (NOAA) Pacific Marine Environmental Laboratory and Andrew Dickson of Scripps, both experts in marine chemistry. Dave Demer at NOAA’s Southwest Fisheries Science Center added a sonar to measure the biomass of fish and zooplankton. Additionally, Scripps’ John Hildebrand equipped the mooring with acoustic instruments to capture sounds emitted by marine mammals. Such recordings, along with the mooring’s instrument readings, will help Hildebrand better understand the environment in which dolphins and whales emit their calls.
Send and Ohman had discussed deploying such a mooring for years, but lacked financial backing to make it happen. They ultimately decided to forge ahead with a patchwork of money from their partners and supporting agencies such as NSF and NOAA. Although extremely valuable, Ohman and Send say they may have to pull the plug on the mooring and its data stream if new funding sources aren’t found. They say what is truly needed is a line of three moorings that make measurements in different sub-regions of the California Current.
“The ocean is changing and we need to understand how, why, and what the consequences are for living organisms,” said Send. “We have to be able to measure quickly evolving phenomena in order to understand cause and effect relationships in the ocean.”
— Mario Aguilera
January 23, 2009