As shark populations plummet worldwide, VIMS researchers are at the forefront of efforts to save these awesome creatures
BY SARA PICCINI
William and Mary Alumni Magazine | Spring/Summer 2006, Vol. 71, No. 3/4
Photo courtesy of David Malmquist
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| Dr. Jack Musick (right) dissects a small Atlantic sturgeon as Sea Grant Commercial Fisheries Specialist Dr. Chris Hager (left) lends a helping hand. |
 Jack Musick: Sui Generis |
In the summer of 1961, a Rutgers University undergraduate named John Musick snagged an unusual job. Assigned to the Sandy Hook lab of the New Jersey Fish and Wildlife Division, Musick joined a crew aboard the fishing vessel Cape May to take part in the first fisheries-independent shark survey ever conducted.
Using longlining methods employed by commercial fishermen, Musick and his colleagues sacrificed the sharks they caught for the advancement of science -- performing necropsies to learn more about sharks' diet, reproductive biology and growth patterns. Musick also kept careful records of catch numbers.
"The sheer seasonal abundance of sharks was a revelation," Musick recalls in his recent book The Shark Chronicles, co-written with his wife, Beverly McMillan. "For me [the trip] began a lifelong shark odyssey that has led me around the world."
Since 1973, Musick's home port has been the Virginia Institute of Marine Science (VIMS) at the College of William and Mary, where he is now Marshall Acuff Professor of Marine Science. He heads VIMS' shark research program, part of the National Shark Research Consortium, which Musick helped to establish in 2002. In addition to VIMS, the consortium includes Moss Landing Marine Laboratories in California and two Florida institutions, the University of Florida/ Florida Museum of Natural History and Mote Marine Laboratory in Sarasota.
Last summer, Musick (universally known as Jack) returned to the Jersey shore where his shark odyssey began. Using the same longlining gear, he again surveyed the waters. "Somebody found my original data -- it was still there, on handwritten sheets," he says. "One of my graduate students, Dan Ha [Ph.D. '06], entered it in the computer and then compared the catch index with the index from last summer."
Once the analysis was complete, the hard evidence proved what Musick already knew.
"It's a hell of a decline," he says bluntly.
"Our own VIMS data had shown almost a 50 percent decline from the mid-1970s to the mid-80s, principally due to the recreational fishing that exploded after the movie Jaws came out," Musick explains. "Hundreds and hundreds of tons of sharks were landed.
"After that, the infrastructure developed for transport of shark fins from the East Coast of the United States to Hong Kong, where they're processed and reshipped around the world to different Chinese communities for shark fin soup, which is a delicacy and a high-priced commodity.
"That was the nail in the coffin. By 1992, we saw a 90 percent decline in some species of large coastal sharks and a 70 percent in others."
The Apex Predator
harks loom in the popular imagination as terrifying beasts, an enemy humans feel powerless to subdue. Shouldn't we feel heartened, then, that there are far fewer of them lurking off our beaches? Absolutely not, says Musick.
"When humans remove a top predator or severely deplete its numbers ... more lower-level predators survive, and proceed to eat a larger share of their prey," he writes in The Shark Chronicles. "The result is a cascade of disturbed ecological relationships, all evolved over countless millennia, all sundered in what amounts to a blip of time."
Musick and his fellow ichthyologists agree that sharks have much more to fear from humans than vice versa. Shark attacks can and do inflict terrible damage, but they are extremely rare.
Even a small understanding of this great ocean predator can turn fear into awe. Sharks are marvels of design, perfectly engineered to swim through the water with speed and grace. A shark's skin, for example, is made up of tiny teeth-like structures called placoid scales that significantly reduce drag. Its skeleton is flexible cartilage rather than bone, increasing efficiency of movement. (Sharks are classified as elasmobranchs, as are skates and rays -- a subgroup of the class Chondrichthyes distinguished by cartilaginous skeletons and five or more gill slits on each side of the head.)
Fossil records suggest that sharks have been around for more than 400 million years -- making them older than dinosaurs -- and that they were the first vertebrate to have a complete jaw.
On an April day this year, doctoral student Jason Romine '97, M.S. '04 stood cleaning one of those jaws in a VIMS lab at Nunnally Hall. The jaw will be added to VIMS' extensive fisheries collection. "It's from a Galapagos shark, a species we don't see here on the East Coast," he explains. Romine, who works under Professor Musick, is involved with ongoing VIMS research in Hawaii on comparative shark populations. "We caught this back in January -- it came up dead," Romine says, adding that the shark had been pregnant. "We're going to look at the genetics of the pups to see if there's multiple paternity."
Breakthrough scientific advances in recent years such as DNA analysis are helping ichthyologists to understand more about sharks, but much about them remains unknown. Unlocking such secrets as shark mating habits and migratory patterns is an essential part of scientific inquiry, but the need for answers goes well beyond pure science: it is critical to the survival of the species.
William and Mary scientists stand at the forefront of this battle.
Vital Research
The shark research program at VIMS includes a broad array of investigations at multiple sites, ranging from an on-site examination of shark vision using sophisticated spectrum analysis to a study of thermoregulation in the salmon shark off the coast of Alaska.
The centerpiece of the program is the longlining survey of sharks in and around the Chesapeake Bay, begun by Musick three decades ago. He's kept it running continuously since 1973, scrounging for funding in lean years.
"It stands as the longest monitoring program for shark abundance in the world," he says.
Now under the direction of R. Dean Grubbs Ph.D. '01, a former student of Musick's and a VIMS research scientist, the longlining crew goes out from May to October on the VIMS research vessel Bay Eagle, captained by Durand Ward.
The longlining crew, made up of about a half-dozen scientists, installs all the gear on a mile-and-a-quarter-long fishing line. "There's a gangion every 18 meters with a clip attached, two meters of nylon line and 1 meter of steel cable that the shark can't bite through. We attach J-hooks to the cable," Grubbs says.
"We have to keep the gear constant, which can be a challenge --now everyone's using monofilament line, for example. We've been able to tweak some things, like installing a hydraulic winch. Now we can set a hundred hooks in eight minutes, and bring in the line in 15.
"We do 10 to 12 four-hour sets in a four-day trip," Grubbs says. The work, although physically exhausting, is highly rewarding. Sharks caught and released are tagged to track migratory patterns. Those sacrificed for research yield crucial information: for example, a shark's age can be determined by counting stratifications much like tree rings within its dorsal fin.
"In order to manage a species effectively, you need to do age and growth work -- to find out how long sharks take to reach maturity, the length of their reproductive period, their methods of reproduction," Grubbs says.
Since 1996, Grubbs has been conducting a survey of juvenile sandbar sharks, the most common species in Virginia coastal areas, and analyzing the elements that make the Chesapeake Bay the prime nursery area for sandbars. "We're also tagging juvenile sandbars to see if females born in the Bay come back to have pups."
Sharks are at a special disadvantage in recovering from overfishing because of their long rates of maturity, long gestation periods and relatively few offspring. The sand tiger shark, for example, which has been especially hard hit, takes about 12 years to mature and has only two pups every other year.
Musick's long-term survey -- sounding the alarm on the crash of shark populations -- has been absolutely essential in pressing state, national and international agencies to adopt shark management programs. "In the mid-1980s, a group of us were pulled together by the Mid-Atlantic Fisheries Council. We asked the National Marine Fisheries Service (NMFS) to put together a management plan quickly, otherwise there was going to be some stock collapse.
"The state of Virginia put regulations in place in 1990 -- Virginia was way ahead of the curve here," Musick says. "It wasn't until 1993 that NMFS finally put a management plan in place that had a quota for the year, and had a bag limit for recreational fishermen."
Hope for the Future
Shark populations hit a nadir in 1992: since the implementation of the national management plan in 1993, ichthyologists have seen some recovery.
"One of the success stories is the dusky shark," Musick says, "We were really worried about it be-cause it's a huge species -- the females are 12 feet long and take 21 years to mature. They only have a litter every three years instead of every other year. But they do have 10 young. We've seen a substantial increase in juvenile dusky sharks now. They're back up to about 30 percent of what they were in the beginning."
Musick and other VIMS scientists are key members of international groups working to implement shark management plans worldwide. Musick co-chairs the shark specialist group of the International Union for the Conservation of Nature (IUCN), headquartered in Switzerland, which compiles the annual red list of endangered species; he was instrumental in the creation of a shark action plan issued by the United Nations' Food and Agricultural Organization. Just this past year, the International Commission for the Conservation of Atlantic Tunas (ICCAT) adopted the first international ban on shark finning. The U.S. ICCAT Advisory Committee is chaired by Professor John Graves of VIMS.
Still, Musick concedes, "it's a continual battle." As he speculates in The Shark Chronicles: "If there are paleontologists a million years from now, I wonder whether they will note that ... in the 21st century A.D. sharks' teeth disappeared from the fossil record."
With a new generation of shark experts leading the way -- many of them trained by Jack Musick -- we can find hope that the mighty shark will continue to roam the oceans for eons to come.
Sara Piccini is a freelance writer from Hampton, Va.
