A New Look Into The Sea

The cost of equipment is high, and Prager has been forced either to do without or, with the help of his assistant, John Mahoney, to devise makeshift equipment of his own. These improvisations would do justice to Dr. Seuss and are labeled as having been manufactured by the Scheckelpincher Company. "There are perhaps a dozen people in the world doing the work I'm doing," Prager says, with a smile. "All of them are in the West. This is one field in which we're ahead of the Russians."

Prager's main interest is the biochemistry of seawater. "Seawater is different up and down the coast," he says. "Actually, when you use seawater in the singular it's a sin. The seawater in Chesapeake Bay is different from that in Raritan Bay, and that's different from Cape Cod. Even offshore there are areas that are biochemically different. And it is these biochemical differences which account for the differing abundance and distribution of phytoplankton, the so-called grass of the sea. Recently in Long Island Sound at Larchmont I picked up an interesting phytoplankton bloom in a yacht harbor. The little inlet was full of them, yet the water in the next inlet, 50 yards away, was as clear as crystal."

In addition to biochemical differences, seasonal changes cause variations in plankton on the continental shelf. "Off the New Jersey coast," Prager says, "diatoms, a group of algae, one-celled plants, start to bloom, proliferate to the point where the water is turbid, in January. Spring turns up earlier in the ocean than it does on land. While we're snowed in, it's spring out there. Why? No one knows the whole story. Anyway, the diatoms are followed by flagellates, one-celled plants that can swim. During the late spring and summer these float in abundance in the water, and animal plankton, zooplankton, predominantly composed of minute crustaceans along with invertebrate larvae and small fish larvae, graze on them." Fish such as menhaden and herring eat the zooplankton, and, in turn, larger predators, such as bluefish and striped bass, eat the menhaden and herring. "In the late fall," Prager says, "the production of phytoplankton largely stops and does not resume again until January.

"To some extent, these plants are regulated by temperature and salinity. They start here at a different time than they do, say, at Georges Bank off Cape Cod. But these plants do require certain organic materials such as thiamine, B12, folic acid and amino acids. We don't know everything about the nutritional requirements of phytoplankton, but we do know that different seawaters have different potentials for growing them. And what we're trying to pin down is the biochemistry behind these potentials to grow plants. Converse to this, once we have learned the nutritional requirements of a pure culture of a single species of phytoplankton, we can use this as a marine white mouse, to measure the amount of a given nutrient that it requires in seawater. Ultimately we hope we will be able to predict toxic red tides and enhance the productivity of nonproductive water by seeding it with microorganisms which will act to enrich the water for other crops. Our own Atlantic coast is the richest phytoplankton area in the world, and the richest single point is probably Georges Bank. It's extremely rich, so rich it's murky. That's why skin divers hate it—they can't see their hands in front of their faces. But the fact is we don't know now the subtle things that make the difference between a rich body of water and a poor one. Maybe all the richness comes from a sheep pasture up in the watershed, and sheep manure is responsible for all of it. Who knows? But we'll find out, or our grandchildren will."

Prager's next-door neighbor at the laboratory, Dr. Ronald Eisler, has been working on pollutants. In a recent experiment, he checked on the toxicity of soaps and detergents to marine life. Contrary to the advertising slogan, Duz doesn't do everything, at least when it comes to killing fish. Duz and other soaps, Eisler learned, "are relatively harmless to fish for the simple reason that soaps can be broken down by bacteria." On the other hand, synthetic detergents are most harmful. "One pound of detergent in 23,-000 gallons of seawater will wipe out half the fish life in four days," says Eisler, "and it will stay toxic for three months." Detergents have a molecular base that cannot be broken down by bacteria.

In an attempt to overcome the pollutants of the present as well as those of the future, Eisler is trying to raise a hardy, disease-resistant race of fluke. While doing graduate work at the University of Washington, Eisler studied under Dr. Lauren Donaldson, who has used selective breeding to raise 3-year-old rainbows that weigh 14 pounds. Eisler is trying to duplicate this feat with fluke. To stimulate growth and accelerate sexual development, he has been giving his fluke injections of thyroid hormones and a sex hormone known as HCG. "Eventually," he says, "we hope to wind up with a race of superfish. As of now, we expect the program to be successful within 30 to 50 years, and I expect to be around then. Given adequate equipment, I think that I could complete it in 20 years. With the estuaries going from pollution and landfill, we have to be prepared." One of the flounders that Eisler originally caught for aquarium experiment was an albino, and he wrote a paper for a scientific journal describing the rarity. The name of the white flounder was Moby Irving.

One of the major programs at Sandy Hook is a study of the life cycle of the bluefish. Eisler and a number of the other biologists are working on various phases of this. "The reason we're studying the bluefish and not some other game-fish," says John Clark, the assistant director, who is in charge of fish tagging, "is that it's the model fish. Everything we learn about the bluefish will be of help. The bluefish is a popular game fish, economically important, caught in abundance, has coastal and worldwide distribution and lives its life in densely fished areas. We're also very much interested in the interaction of the environment and fish, and the bluefish responds beautifully to temperatures. A lot of fish react in subtle ways, and because the ways are subtle and the interaction so complex we don't know what's going on. But bluefish respond beautifully to changes in the environment."

Eisler is trying to distinguish differences between populations of bluefish by analyses of blood. The blood chemistry of marine fishes is a virgin field, but after a year's research Eisler has strong evidence that New Jersey blues can be distinguished from North Carolina blues on the basis of four different blood components. Since the Sandy Hook lab simply lacks the funds to maintain stations elsewhere along the coast, Eisler had to drive down to North Carolina last summer to collect bluefish. He had only two days to do the job, and he had to hire a $50-a-day charter boat to catch the blues himself with hook and line. He needed at least 20 fresh from the sea, but on the first day out the blues were not biting, and he caught only seven. On the second and last day, however, they struck with ferocity, and Eisler and a friend caught 60 in 40 minutes. To help Clark with the tagging program, Eisler tagged the blues he did not need, packed the rest in an ice chest in the back of his car and roared back to Sandy Hook, where he and his assistant, Dave Deuel, ran blood analyses. But what tickles Eisler most about the trip is that one of the 27 blues he tagged was caught by an angler who returned the tag to Clark.

Herbert Anderson, a summertime biologist at Sandy Hook who is studying for his doctorate at the University of Miami, is noting the species composition of parasites occurring in blues as a way of telling differences between populations, and Walford himself is working on anatomical variations. "We do find differences," he says. "They are exasperatingly slight, but they are consistent." As of now, the thinking is that there are two main populations of bluefish, one dubbed Population A, the other B. Population A winters off southern Florida in January and February. Population B apparently winters farther south but shows up off Palm Beach in April. Population A moves north to Cape Hatteras in May, peaks in August off Long Island and New Jersey and retreats to Hatteras in October before returning to Florida. Population B simply moves up to North Carolina in July and stays there until fall. "They may be in the process of becoming two different species," Walford says. "We may be seeing evolution actually under way, in a very slow process, of course."

Although temperatures are seemingly responsible for the two blue populations, Walford doubts that temperatures trigger their separate migrations. "It is something within themselves, a biological clock perhaps, that impels them to move," he says. "We think that the most likely external factor that could influence them would be the sun. That is the theory anyway."