Cruising the current, 70 years onward
Scientists’ survey off the California coast offers extensive look into the ocean’s past.
SAN DIEGO — When the research vessel Bold Horizon set sail out of San Diego Harbor last week, it launched a journey from balmy coastal waters into rough open seas, through microscopic plankton to global whale migrations.
The cruise is part of the California Cooperative Oceanic Fisheries Investigation, or CalCOFI program, a continuous research effort that extends from the California of the 1940s to the next century, where rising seas and warming waters are remaking the ocean as we know it. This year marks its 70th anniversary of investigating the California Current.
The program began in 1949 in an attempt to understand the collapse of the state’s prolific sardine fisheries, which provided a backdrop for John Steinbeck’s novel “Cannery Row.” It quickly evolved into an exhaustive system for studying just about everything you might want to know about the ocean ecosystem off Southern California.
The National Oceanic and Atmospheric Administration, Scripps Institution of Oceanography and the California Department of Fish and Wildlife conduct quarterly surveys of the California Coast from the Mexican border to either Point Conception or to San Francisco, depending on the season.
Those trips have yielded the oldest and most extensive time series in marine science, and offer a window on the ocean’s past.
“In the 70 years that CalCOFI has existed, it is the largest ... ocean ecosystem survey in the world,” said Director Brice Semmens. “That unique spatial and temporal extent of the program really allows us to understand how the ocean changes, and to understand what future change might be coming, and to manage our ocean resources as well as we can, in the face of ongoing climate change.”
On Wednesday, biologist David Griffith was installing portable pumping equipment before the ship departed the next morning. Connected to an overboard pipe, the pump continually streams ocean water through filters that extract fish larvae for collection, and is part of the well-oiled scientific machinery that occupies every usable space on the ship.
CalCOFI has amassed 50,000 samples of fish larvae, consisting of 2.5 million individual larvae from 500 fish species, said Ralf Goericke, a research oceanographer with Scripps.
The larvae, along with fish eggs, represent the numbers and locations of adult fish, and help researchers track changes to fish populations in the Southern California Bight. The program has also gathered water chemistry samples showing increasing ocean acidity since the middle of the last century.
“They are an invaluable resource,” Goericke said. “People are going back to those samples to ask questions about the ocean from 50 to 75 years ago.”
The Bold Horizon is one of several ships used for the quarterly research cruises, and operates as a floating laboratory, with instrumentation for capturing data on the smallest and largest inhabitants of the California Current. There is equipment for gathering fish eggs, testing water chemistry, and listening to the ocean acoustics of whale songs. There are observer stations where researchers count sea birds and marine mammals. And there are mobile labs for analyzing the data at sea.
Dan Schuller, the chief scientist for the cruise, manages the logistics of the ship, ensuring that all necessary equipment is loaded, cabin assignments are made and schedules are observed. In a kind of Noah’s Ark of scientific gear, they bring two of everything essential, he said, since if anything breaks down, “we can’t stop at Home Depot” to replace it. He also ensured the ship was equipped with a cappuccino maker, a device essential to its operations.
“That’s the most important instrument on this ship,” he said.
When researchers refer to the expedition as a cruise, they’re not talking of the leisurely voyages that vacationers enjoy. The ship offers tight quarters and long shifts. Scientists have their meals in the galley and share tiny cabins with bunkmates. To make the most of their time at sea, they make observations around the clock, working 12-hour shifts from noon to midnight, or midnight to noon.
Volunteers — mostly professional scientists who want to lend a hand — also work half-day shifts from 6 a.m. to 6 p.m., said Natalya Gallo, a postdoctoral fellow at Scripps Oceanography who works for the CalCOFI program and is volunteering on the July trip. Although many researchers rely on information gained during the cruises, the cost of ship time — about $15,000 per day on the low end, according to Schuller — means that only a handful can participate in hands-on collection.
“Being a PhD student at Scripps, I really became a scientist by learning about the CalCOFI program,” Gallo said. “I’ve always been analyzing the data, so to go to sea and learn how the data is collected, that’s really important to me.”
The ship sails along transects perpendicular to the shore, stopping at fixed sites every two to four hours, and hitting 75 to 115 of those spots, or research stations, per trip. At each station, NOAA scientists collect fish eggs and larvae, using various nets at different depths, while Scripps researchers measure water temperature, salinity, pH level and other chemical properties.
The workhorse of that effort is a circular device fitted with metal canisters, and equipped with sensors. It’s lowered to depth on a cable, where the sensors transmit measurements to computers on board the ship, and researchers can view real-time charts of the results. It’s an improvement over previous gear, which required researchers to manually lower and raise individual tanks, Goericke said.
“It was backbreaking labor,” he said.
At the same time, a signal prompts the device to shut the canisters, trapping water samples for later analysis. The water is stored in flasks that form a liquid library of decades of ocean water. One of the key functions of recent CalCOFI cruises is determining how climate change is altering the ocean’s hydrology and ecology. The flask collection bears troubling testimony to the fact that the ocean, in absorbing atmospheric carbon, is becoming increasingly acidic, a change that can hinder shellfish and coral formation, and disrupt reproduction and behavior of other sea life.
“They allow us to show that the pH in the Southern California Bight has slowly but steadily dropped over the last 30 to 40 years,” Goericke said.
The work may seem esoteric; not everyone is attuned to the fate of sardines and anchovies. But Dave Checkley, director of the program from 2013 to 2017, said the research on fisheries and oceanographic conditions trickles up to things that nearly all of us find important, from our beaches to our food supply.
“What happens at the coast, where people go in the water, is very much influenced by what happens at the end of the waters five miles or 50 miles offshore, in terms of the health of the beaches,” he said. “So understanding the ecosystem out there is vital to maintain a healthy ocean that people enjoy. Things such as swordfish and albacore that people catch and eat, these feed on anchovy, sardine and squid. The better we understand the forage fish, the better we understand the larger migratory fish.”
The surveys provide seasonal snapshots of the California coastline, and its historic role in the culture and resources of the state. As they embark on routes sailed by earlier generations of oceanographers, the researchers are aware of their place in that continuum of science.
“I think the really cool thing about CalCOFI is you are getting this legacy that goes back to Steinbeck,” Gallo said.