You’d never suspect that Sherry Cummings worked hundreds of miles offshore, 12 hours a day, much of it spent hauling and dropping a big water collection device called a rosette, which, when full of samples, weighed 1600 pounds.

For more than 45 years scientists from the Scripps Institution of Oceanography and the Southwest Fisheries Science Center have been studying the body of water that sweeps down the California coast. They are seeing changes — surface warming, population declines — that may be cause for alarm.

The bongo nets were used to make an integrated tow, which started down deep, usually at 200 meters.

After 250 cruises in five decades, some 32,000 samplings, more than 90,000 hours of analysis, the California Current has become the most intensively studied large-scale ocean ecosystem in the world.

It was a lovely July night, with a star-filled sky, the sound of seals splashing in the harbor, and the occasional cries of pleasure from those fishing off the pier at Port San Luis, south of San Luis Obispo. Kenric Osgood and I were waiting for a ride out to the David Starr Jordan, a National Oceanic and Atmospheric Administration research ship. I had come along to meet scientists with CalCOFI — California Cooperative Fisheries Investigation. CalCOFI had recently received national attention following an article in Science magazine stating that zooplankton levels off Southern California had dropped by 80 percent in the past 40 years, possibly due to ocean warming.

Onboard nutrient analysis. After 250 cruises, some 32,000 samplings, more than 90,000 hours of analysis, the California Current has become the most intensively studied large-scale ocean ecosystem in the world.

Kenric Osgood was there to continue his study of one of those zooplankton organisms, calanus, the “sea cow,” which grazes on floating plant life and accumulated oils, and, small as a grain of rice, serves as an important food for many fish. Kenric was particularly interested in the 11th of 12 growth stages of calanus, and he would be using an optical particle counter to come up with numbers of calanus-sized animals in the waters off Santa Barbara.

Together we had spent six hours navigating the freeways from La Jolla through the metropolitan snarl to get to Port San Luis. When Kenric called the Jordan at 7:00 p.m., he was told the ship would arrive at 10:00, a three-hour wait that bothered him but didn’t bother me. I ate at Fat Cat’s, a diner-style restaurant by the parking lot, and would have eaten at the fancy place at the end of the pier if I’d had a chance. But then a Zodiac streamed in, two tousled-looking scientists disembarked, Kenric loaded his gear, we jumped aboard, and Chico Gomez, chief boatswain, raced off, circled the Jordan, and with a figure-eight flourish, pulled alongside. Kenric and I were helped up the ladder, the Zodiac was hauled aboard, and the Jordan headed back offshore.

The California Current is part of a huge clockwise flow of water that circulates through the North Pacific — westward through the equatorial Pacific, turning northward near the Philippines, bending eastward as it brushes by Japan and is pushed by prevailing winds along the west wind drift. Joined by subarctic currents, the stream divides as it nears Washington, one branch curling off into the Gulf of Alaska, the other branch, the California Current, flowing south before turning west again off the tip of Baja.

Like California the state, California the current is a vibrant mix of many origins — five, in fact: 1) waters from the west wind drift merge with 2) cool and nutrient-rich waters from the SubArctic Pacific, which join 3) warmer offshore waters coming from the west and 4) even warmer equatorial waters coming from the south by means of a countercurrent, all of which, as they move horizontally, are affected from below — vertically — by 5) highly fertile waters welling up from the deep.

The California Current is no Old Man River; the character of the water is complex and ephemeral. Narrow meanders switch back and forth at high speeds. Eddies and whirlpools spin like ball bearings, sending off “squirts” and “jets” and “filaments” that rapidly pull water away from shore. Temperature gradients pile up and tilt like tectonic plates. There are shifting density layers and salinity layers moving with the flow. These “thermoclines,” “pycnoclines,” and “haloclines” often act as fences and pathways for marine life.

All five sources of the California Current bring their various life forms, and these mix with species native to the California coast. The ecosystem that forms has been described in one Scripps bulletin as “a succulent seafood stew, with ingredients that vary according to Chef Neptune’s whim.”

Over the centuries, two predominant ingredients of the stew have been anchovies and sardines, vast schools of them feeding on the zooplankton and serving as important prey sources for larger fish, mammals, and birds — and in this century, commercial fisheries. Populations of sardines and anchovies have exploded and collapsed according to the natural ebb and flow. At about A.D. 575, the anchovy population in the southern California Current was 5 million metric tons (11 billion pounds) but then nearly disappeared shortly before 1300. Since 1970 populations have ranged between 1.6 and 0.3 million metric tons.

Sardines and anchovies have tended to alternate in abundance. In the 1940s, the sardine fishery in California was the largest fishery in the world until the population plummeted. Many thought the cause was overfishing, it seemed an obvious conclusion; but others, particularly those in the fishing industry, thought the cause might be natural, part of the ebb and flow. The California Department of Fish and Game recommended a closure, but fishermen appealed to the legislature for a tax, per ton of sardines, to finance scientific study of the fishery. Thus, CalCOFI was born.

The “Cooperative” part of CalCOFI is an important element of its success, as three agencies came together to do the work: Scripps Institution of Oceanography, the Bureau of Commercial Fisheries (later the Southwest Fisheries Science Center, an arm of the National Marine Fisheries Service), and the California Department of Fish and Game. (Recently the cooperation has extended worldwide, with the database accessible on the Internet.)

The scientists who organized CalCOFI knew that the issue was larger than sardines, that the problem was a multi-species one and linked to the environment in a broad way. It was a unique view in 1949. Those “visionary-type scientists” (according to John McGowan, a Scripps biologist who, as a graduate student, went on a CalCOFI cruise in 1951 and who coauthored the Science article) exploited the sardine fishery collapse, pursuing a vision for a big study of a big area, with monthly cruises sampling seawater at hundreds of stations. They did this for ten years, running three ships in zones from southern Baja to Oregon. But as time passed, costs increased and funding diminished, and CalCOFI eventually settled down to one ship, four cruises a year, with offshore stations from Del Mar to Purisma Point (south of Port San Luis), 40 miles apart on lines that run as much as 350 miles out to sea. In the process, the science of fisheries oceanography came into being.

Though sardines have returned (the spawning biomass was estimated at 116,200 metric tons in 1993) and the commercial fishing has resumed (landings in 1993 were 13,848 metric tons), the vision and the study continue. In 1989, the 40th anniversary of CalCOFI and the year that sardines reappeared off Monterey, there was a celebration at Scripps.

Coincidentally, 1995, the year of publication of McGowan’s Science article based on the accumulated CalCOFI data, is also the 50th anniversary of the publication of Cannery Row, which depicted the fishery that sprung the study.

Forty-five minutes after leaving Port San Luis, the David Starr Jordan reached Station 66, on Line 77. It is the station closest to shore on the most northerly line, the last sampling of the cruise. Sherry Cummings, an oceanographic technician who works at Scripps, had suggested that the crew save a station until I came aboard so I could see how the work was done. It was a generous gesture, considering they’d been at sea for two weeks, the two crews working round the clock on watches from midnight to noon. Together they had sampled 65 other stations and wanted to get the work done. But they agreed to wait because the weather had been nice (unlike the cruise in April, when they tossed and thrashed about for three weeks, holding themselves in their bunks while they slept, holding everything still while they ate, holding their emotions in check), and they were a few days ahead of schedule, and there was an easy weekend ride to the dock at Point Loma yet to come.

To look at Sherry, you’d never think she’d been going to sea for 12 years, four times a year, three weeks at a time. You’d never suspect that she worked hundreds of miles offshore, 12 hours a day, much of it spent hauling and dropping a big water collection device called a rosette, which, when full of samples, weighed 1600 pounds. If you saw Sherry onshore, and she smiled and quietly said hello, her green eyes lighting up, you’d never know of how sometimes, as they were bringing in the rosette, the ship rocked with the big waves and water poured over the sides and they had to hold on so as not to be swept away. And of course you wouldn’t know about the stress of being offshore for long periods, the mail piling up, and the bills coming in — one time her car was stolen while she was at sea (and the news arrived, “Oh, by the way...”), and she had to deal with it while continuing to work the stations on the noon-to-midnight shift.

Station 66 is a few miles off Purisma Point. There the ship idled while Sherry, with the help of Chico Gomez and Anthony Assaro, who ran the winches, lifted the rosette over the rail and down into the water. The cable payed out behind it.

The rosette is basically a ring of four-foot tubes attached to a stand, like a circle of organ pipes. Each tube holds ten liters of water. The caps at top and bottom are spring-loaded and triggered shut from a computer terminal, so samples can be retrieved from any depth within range. Normally the rosette is lowered to 550 meters, and 20 tubes are triggered at 10- to 50-meter intervals on the way up. But Station 66 is a shallow one, about 90 meters deep. Sherry decided to fill 8 tubes at 10-meter intervals.

We watched the water column on a computer screen and the course of colored lines that corresponded to temperature, salinity, water clarity, and the presence of chlorophyll, or plant life. That line, the green one, was way above the others. “There’s a huge phytoplankton bloom now,” Sherry said. She triggered a tube, and another. Down below, caps snapped shut as the rosette ascended.

“Last station,” she said with a smile, though a tired smile, in a voice with a faint note of stress. This was when I asked about life at sea. Sherry said she liked her job, and she was happy to have gotten it in 1983. But after 12 years she thought the time had come to move into a position that was land-based, analyzing the CalCOFI data perhaps, which involves only occasional cruises.

The rosette surfaced and was hauled over the rail and fastened to the deck. Sherry went about filling sample jars and labeling them. Some would undergo tests onboard, and others would be stored ashore. Storage has become a problem, though. CalCOFI has the most extensive library of its kind in the world, but the boxes of samples, going back to 1949, have filled storeroom after storeroom.

While Sherry worked with the rosette on the starboard side of the Jordan, doing physical oceanography, Ron Dotson and Amy Hayes, working for the Southwest Fisheries Science Center, did their work on the port side, they used nets and practiced fisheries biology.

The first net went down for a vertical tow immediately following the recovery of the rosette. A long sock of fine mesh, a “pairovet,” was lowered like a bucket into a well, down to 70 meters, and then pulled straight up. The catch consisted of a brownish-green slime — the primordial ooze — along the sides of the net. Ron sprayed it down to the tip of the sock, and then Amy gathered the contents into a jar. She walked off into the lab and held it up to the light. “Full of goodies,” she said, and there was a lot floating around — a tiny diaphanous flounder, a larval rockfish, shreds of plant life, and fish eggs. This was the succulent California Current seafood stew, a ladleful of it.

The second tow was done with a manta net (wide and flat and like a manta ray) pulled through the upper five inches of the water column for ten minutes. The target was surface neuston, or small, swimming zooplankton (the manta also picked up insects that lived in the interface between water and air). Again the catch was a brown slime, sprayed, jarred, and filed away.

The third tow, the last sampling of the cruise, was done with the somewhat spectacular bongo net, two rings that look like the heads of bongo drums and from which proceed long, conical socks. Held up, it looks like a double-breasted windsock. The bongo nets were used to make an integrated tow, which started down deep, usually at 200 meters, and ascended obliquely at a 45-degree angle through the water column. This was for a quantitative measurement — how much, of what. While the ship steamed ahead at one and a half knots, Ron kept his eyes on a meter near the cable to make sure the angle of attack was within the right zone.

Ron Dotson is an old biological hand. Sunburned, slightly weather-beaten, bearded, he’s been working with CalCOFI since the early 1970s and has made dozens of voyages. He has intermittently worked on other government fisheries studies, for hake and swordfish and other species, usually off California, but occasionally getting as far north as the Gulf of Alaska. Ron spends 180 days a year at sea. It is the life of a fisheries biologist and brings the rewards the profession has to offer — the beauty of oceanic surroundings, the time and place to think. But he pays the price too, the consequences that come from any decision. Life moves along without you. Ron’s grandson had been born on the first day of this trip. Relationships can become strained — you need a partner who is independent and can be on her own for weeks at a time.

Up came the bongo net, dripping and smeared brown. The contents were jarred and the collection work of CalCOFI, July 1995, was done. The 198 jars collected by the Southwest Fisheries team would be transported to La Jolla. There, total volumes for each haul would be measured. Using single-hair brushes, plankton sorters would separate fish, eggs, and larvae from the rest of the samples. This icthyoplankton would be identified, as many as 500 species in 150 families of fish. The results would be published in an atlas and used in formulas (numbers of sardine eggs per unit of water, for example) to determine spawning biomasses, and from there, commercial fishing quotas.

Even before the Jordan reached home, analysis of the physical state of the California Current was already underway. In an office perched above a high cliff overlooking La Jolla, Arnold Mantyla had begun assembling a profile. Mantyla is an expert in deep-sea currents, and, using the data sent from the Jordan’ s computers, he can read the California Current like a riverman reads the river. Nov a major jet had formed from a meander and was shooting straight ahead. There was a body of “heavy,” cold water tilting up from the west. There were abrupt temperature changes close to shore, going from 12 degrees centigrade on the beach to 18 degrees five miles offshore, though that hot spot was a “thin skin,” the temperatures below dropping off quickly. Off Point Conception there was a chlorophyll bloom four times greater than normal and an extremely high level of chlorophyll near the Channel Islands. This bloom could have resulted from some very deep layers of water, rich in nutrients, that had started coming to the surface in January.

Off the Channel Islands a cyclonic eddy had arisen, a big donut of water with compressed outer rings supersaturated with oxygen. It was along this eddy, earlier in the cruise, that 10 blue whales had been sighted with 15 sei and finback whales. This was the first time that blue whales had been seen in this area, this close to shore, and it was a most remarkable phenomenon, that these animals, the largest creatures ever to live on earth, 100 feet long and 130 tons, had come to feed on zooplankton in a compressed eddy of the California Current. The blue whales and the soaring plankton bloom, along with the recent tapering off of water temperatures in the past four months, seemed to call into question the idea that life in the California Current might be diminishing.

Those assertions, explained in the Science article, were based on a simple principle: The temperatures of the surface waters in the California Current had risen in the past four decades, by one to two degrees centigrade. This caused the surface waters to expand and become less dense. As a result the difference, or gradient, between upper and lower waters was greater. This meant that water upwelling from below — the vertical factor in the California Current — was coming from shallower depths. The upwelling waters are to phytoplankton as soil is to the garden, providing phosphates and nitrates drawn from decomposed life floating down from above. Thus, the deep upwelling waters are the source of fertilization for the phytoplankton — the green garden — of the California Current. If fewer nutrients were rising, and less plant life was being generated, then it could be said, as in Science, that the 80 percent drop in zooplankton, which feeds upon phytoplankton, is a result of the increase in surface temperature.

There is speculation on the cause of the temperature increase. El Nino could be a factor. Human civilization — global warming from increased carbon in the atmosphere — could be the cause, which carries a bleak prospect if the trend continues (the disappearance of an elemental part of the food chain). But there is also the possibility that the temperature change was part of a natural decade-scale fluctuation. Climatologists at Scripps are claiming that temperatures in the eastern Pacific are dropping back to cooler levels of the 1970s.

Whatever the cause, as John McGowan has stated, if there is such a thing as global warming, it will look like what has happened to some populations in some parts of the California Current over the past 40 years.

At midnight the shifts changed. David Griffith, chief scientist for this cruise, and Dimitry Abramenkoff, an SWFSC fisheries biologist, replaced Ron and Amy. The next morning, other technicians from Scripps were at work testing water samples. In one lab, Barry Nisly, a mechanical engineer by training, tested for the presence of nitrates, nitrites, silicates, and phosphates, on a device with coils, twists, and turns of plastic tubing (“1970s-vintage technology”), the water turning various colors as it interacted with chemicals and moved along. In another lab, a closet-sized room called the salt mine, Ed ran electrical conductivity tests to determine levels of salinity. Results were automatically fed into a computer. In another lab, James Wilkinson, a computer programmer and analyst, was overseeing a system called CUDLS (pronounced “cuddles,” a name Wilkinson didn’t like very much), CalCOFI Underway Data Logging System, which gave a continuous reading of surface water, picking up the finest intricacies of the current.

The Jordan moved leisurely down the coast toward Point Loma. People lounged around, when not packing up or gathering materials together. At noon the lunch bell sounded. Meals onboard the Jordan were excellent (tamales, burritos, western omelets, shrimp, and the last night, prime rib) and came like clockwork (0730 to 0830; 1130 to 1230; 1700 to 1800), crew and scientists filing into the mess room with the clang of the bell, to the patter of Rick, the chef. He has a gray ponytail and a Fu Manchu mustache and can cook in a rolling galley, putting in more hours than anyone, going from five in the morning till eight at night.

During lunch, Noah Gomes, the first engineer, offered to give me a tour of the ship. Noah and I had an acquaintance in common. When he was young, Noah had been a commercial fisherman working in the San Diego tuna fleet on the boats of Salvatore Ingrande and his son Leonard. I knew Leonard Ingrande because I had written a book about the Bluefin tuna fishery in New England. In 1963 Leonard had taken his purse seiner through the Panama Canal to Massachusetts, and during the 1970s he and his two partners had developed the Japanese markets for giant Bluefin tuna. Leonard now owned shares in three of the five purse seiners working in New England.’ Noah Gomes had gone out once on a boat with Salvatore Ingrande in the early 1950s, and the caulking had come loose 200 miles offshore, and they’d barely made it back.

After lunch I followed Noah up the stairs to the third deck. He told me the David Starr Jordan had been built in Sturgeon Bay, Wisconsin in 1964, that it was 171 feet long, that there was a climate-control system (“We try to keep it at 72 degrees; we don’t always succeed, but we try”), and that it had a helicopter pad, making it the smallest aircraft carrier in the U.S.

In the control room we met Captain Jim Herkelrath. Out the windows was an extraordinary view of two of the Channel Islands, Santa Rosa and Santa Cruz. The ship was passing between them. How wild and untouched they looked.

Captain Herkelrath also pointed out a man standing at an observation area on the flying bridge on the second deck — Dick Veit, a research scientist from the University of Washington. Veit studies birds, and he has a passionate interest in the Sooty Shearwater, which feeds at night on zooplankton and dives as deep as 200 meters to find high densities of food. By day the birds rafted up, and Veit got his counts then. The Sooty Shearwater had been the most common bird in the Pacific Ocean during the 1970s, when there were as many as 10 million. But since 1987 their numbers had rapidly decreased, by 90 percent, a decline coinciding with the warming trend and the zooplankton depletion. Oddly, other populations of birds, such as the storm petrel, were increasing offshore. This spring, with the phytoplankton bloom, there had been no noticeable increase in Sooty Shearwaters, though there could be a response in time, Veit thought, since they had a life span of 30 to 40 years.

Noah Gomes took me through the computer room and showed me the officers’ quarters and the infirmary, the library, and the movie room, and he took me through various storerooms and tool rooms. In one, just over the bow, he said he wanted to show me the “bow bubble” and opened a hatch in the floor. “Stay here,” he said, “and when I open the next hatch, you come down.” He disappeared down a ladder, and then I heard the call. I went down through the hatchway, hand over hand, and then down through another, below into a dark chamber.

Noah was crouched down, and smiling, in a bulbous room, nine feet long and five feet wide, projecting off the bow. There were five portholes, each a foot in diameter. One faced straight ahead, two were straight to either side, and another two were angled downward. The green light in the room was from the seawater — we were moving through the plankton bloom, like a misty underwater jungle.

I tapped the walls. “Three-eighths inch,” Noah said, “reinforced.” I kneeled on a mattress covered with a white sheet. “Lay down and take a look,” he said. I did, and looked out. I could see the bow wake peeling off overhead. I wondered what it would be like to see a blue whale from this room.

“Sometimes dolphins come right up and look through the windows. They can see right in.” There was a light in Noah’s eyes that I recognized, that I had seen among Portuguese fishermen in New England. “You can see schools of fish from here too,” Noah said. And when phosphorescent plankton were in the water, they looked like snow.

Lying there and looking out, hoping a dolphin would turn up and peek in, I remembered another time, when I’d been a student in Europe and had gone to Egypt for Christmas and taken a trip to the pyramids. Another energetic and enthusiastic man had led me up a stairway into the central chamber of Cheops and spoken to me in English about the pharaohs and their tombs.

This chamber, just then, seemed equally remarkable and wondrous. This bow bubble was an expression of vision and even of generosity (the fact that it was there) and also of eccentricity, that odd and important quality we find in humans and other creatures (there are eccentric honeybees for instance, which read the dance directions wrong and find new sources of nectar).

This was about vision, this looking into the green water; and taking part in it myself, thinking that as a citizen I was somehow connected to this, I thought — this is what’s good in government. In a time that often in the public realm seems to be mean-spirited, and lacking in vision, when politicians seek to appeal to the ungenerous, judgmental, and cruel parts of' us — this was a reminder of the capacity for generosity and vision.

Oceanography itself was about vision. Dick Veit, standing at the flying bridge and scanning the water for Sooty Shearwaters, that was about vision, as was Kenric Osgood, looking for calanus — and the fact that this government research ship would take them aboard, include them in an informal way, that was about generosity of spirit. Sherry Cummings, using the rosette, that was about vision, as was Ron Dotson’s drop of the net into the planktonic realm. CalCOFI itself was both visionary in concept and visionary in fact — a broad, long, considerate look into the sea with a concern for how things were going. This bow bubble, that was the quintessence of vision — to look, to regard, to take things in, to contemplate on that seen, to report the findings.

Isn’t this what the ocean has always given us, vision, a way of seeing, a far-reaching sense of possibility?

Noah and I ascended through the first hatch and the second; if the ship did collide with anything and the bubble did break, no water was getting through. Then we went to the engine room, which was Noah’s office. Two 534-horsepower diesels thrummed with a roar that was deafening here and a background vibration in the rest of the ship. We wore headsets, and Noah yelled through mine — I heard a distant voice telling me about fuel capacity (54,000 gallons), daily fuel consumption (800 to 900 gallons), propeller size (two of them, 5.7 feet wide), and temperature in the engine room (about 100 degrees). We walked on planks by the engines and finished the tour by the spinning propeller shafts.

That night, just before sunset, Ron Dotson found a fishing spot on the fish-finder. The ship stopped east of Santa Barbara Island, and out came the fishing poles. About ten people lined up, crew members, biologists, technicians, and even the captain, who stood off to the end of the line, smoking a cigar. It was calm and warm. Everyone watched while the sun dropped below the horizon.

One fisherman was doing quite well. His name was Pedro, and he worked as a crew member. Pedro had a rod holster and used shrimp flies, and he was hauling in starry rockfish at a rate of four-to-one to everyone else combined. He had a dry sense of humor with an ethnic tinge, an irony of assumption. Each time Pedro pulled in a fish, he glanced about and quietly said, “The kids. Now I can feed the kids.” When he pulled in a small one he said, “The little girl. This one is for the girl.” When all was done and the ship moved ahead, Pedro bagged up his fish to take home. “The kids,” he said a last time with a wry smile. “They’ll eat another day.”

Following this cruise, the David Starr Jordan would study the impact of ultraviolet light on the genetics of fish larvae. Later there would be tests of laser technologies for assessments of fish stocks. In the fall there would be a marine mammal survey, with a special eye out for the blue whales.

The ship steamed through the night, scheduled to arrive at Scripps’s Nimitz Marine Facility at 8:00 a.m. Friends and family were waiting; for many it had been 16 days. The ship docked, reunions were made, and people began to drift away. I left to take a walk on the beach at La Jolla. The next morning, some of them returned with vans and trucks, and within a few hours they had everything loaded — the computers, the nets, the rosettes, the samples, the notebooks. They would return in October, when the next CalCOFI cruise was scheduled.