October 15, 2012

On a July afternoon of clear skies and calm waters, getting paid to spend time on the Chesapeake Bay is a job many of us would envy. “But when it’s below freezing, when you have to break the ice just to get the boat out, there’s a north wind blowing against the tide, and the spray is freezing on the deck ... those are the days it’s not as much fun to be out there,” says boat captain Hank Brooks. “Of course,” he grins, “I love it on those days too.”

Brooks is a fisheries scientist and research vessel captain, and is part of a dedicated team of researchers at the Virginia Institute of Marine Science (VIMS) who are working to protect the fisheries that are key to the culture and economy of our state. For many of the researchers, that means getting out on the water and catching fish—whatever the weather.

Located in Gloucester Point, on the banks of the York River, VIMS has been studying Virginia’s marine life since its founding in 1940. “VIMS are our science advisors,” says John Bull of the Virginia Marine Resources Commission (VMRC). “They are the state’s marine biologists.” And, as part of the College of William and Mary, VIMS is training the next generation of marine scientists as well.

That’s important, because fish—and fishing—have always been at the heart of life in Eastern Virginia. Fish and shellfish were an important element in the diet of the Native Americans who lived along the banks of the Chesapeake and its tributaries. Capt. John Smith was so impressed by the bounty of the region that he wrote in 1608 “neither better fish, more plenty, nor more variety for smal [sic] fish, had any of us ever seene [sic] in any place.” (In the same note, he also advised against trying to catch the fish with frying pans.)

That bounty was appreciated by the early colonists as well; shad and sturgeon are thought to have helped the Jamestown settlers survive the “starving time” of 1609.

And once the colonists started fishing, they didn’t stop.

Today, commercial fishing is worth an estimated $478 million to Virginia, with the seafood industry providing roughly 3,900 full- and part-time jobs. And recreational fishing has an even bigger impact. Approximately 750,000 anglers fish each year just for fun, creating an annual economic impact of $823 million.

<< UNDERSTANDING THE PAST

In order to prevent future disasters, it is important to understand the past. And few major Virginia fisheries have seen their fortunes fall as far as the American shad.

In 1994, Virginia banned all recreational and commercial fishing for American shad due to the species’ dwindling numbers. (In 1897, commercial fishermen in Virginia were hauling in 11.5 million pounds of American shad per year, but by 1990, the catch had dipped to less than 500,000 pounds.) Commercial fishermen objected to the moratorium, and the ensuing debate highlighted how little anyone actually knew about the American shad population in Virginia waters. In 1998, VIMS researchers were called in to monitor the existing population, and examine historical data, with the goal of determining when the moratorium could be lifted.

The VIMS American shad monitoring program uses the exact same fishing methods used by commercial fishermen in the past, but on a much smaller scale. “This way we can compare our catch data to the historical data,” says Eric Hilton, an assistant professor of marine science at VIMS, and co-director of the shad program. “By comparing the two, we can assess the abundance of the current stocks of American shad, relative to their abundance in the past. That can tell us whether the population is recovering.”

Hilton’s team is working with watermen who fished for shad before the moratorium, setting out staked gillnets in Virginia’s tidal rivers during the shad’s spawning season, from late February through May. The fish they catch are analyzed to determine their sex, size, weight and age, and whether they were spawned in the wild or released from a hatchery. All of this information helps the researchers determine how the population is faring. And the news isn’t good.

“What we’re seeing is a population whose stocks still haven’t recovered,” Hilton says. The number of American shad in the James River, for example, is one-third of what it was 30 years ago.

What makes it even more frustrating is that there does not appear to be a silver bullet solution to bring the shad back. “Why haven’t the shad come back? That’s the million dollar question. We still don’t know,” Hilton says. “That’s why a program like ours is important. The more we learn about these fish, the better able we are to help them recover.”

The perilous state of the shad fishery also highlights a key point: Once a fish population is in danger, it’s incredibly difficult to bring it back from the brink. All the more reason to ensure that other important fish populations are protected.

<< STUDYING THE PRESENT

In order to make sound decisions about how to protect a fishery, government regulators need good information. In Virginia, that information comes from VIMS. More specifically, it comes to the surface in nets.

Few fish are as beloved as the striped bass. Recreational anglers spend countless hours trying to catch them, and gourmands spend countless dollars for the opportunity to dine on them. When you consider the amount of money spent on rods, reels, fishing licenses, and at restaurants and seafood counters, it’s clear that striped bass do more than their fair share for Virginia’s economy. Protecting this resource is important.

VIMS began the juvenile striped bass seine survey—a seine is a long fishing net with weights at the bottom and floats at the top—in 1967, with the express goal of assessing the number of striped bass born in the Virginia portion of the Chesapeake Bay and its tributaries from year to year. In the seine survey, VIMS scientists travel to 39 different sites around coastal Virginia, wading into the water with a 100-foot net and sweeping it back to shore in a loop. When they haul the net in, they sort through the fish they’ve caught—identifying the various species, measuring them, and releasing them back into the water.

Regulators use the information they collect to forecast what the striped bass population in the Chesapeake will look like several years down the road. Those forecasts are used to set limits for commercial and recreational fishing.

“The public expects striped bass to be there in the future, and we’re helping state and regional fishery managers ensure they meet that objective,” says Mary Fabrizio, associate professor of marine science and one of the co-directors of the survey.

But the seine survey catches more than just baby striped bass. The net isn’t selective, and each year the survey hauls in fish of more than 60 different species. “It’s a valuable source of data on the population numbers of smaller fish species that serve as food for striped bass and other important sport fish, as well as bald eagles and other wildlife,” says Leonard Machut, a fisheries scientist and co-director of the seine survey. But the diversity found in the nets is nothing compared to what researchers find in the granddaddy of the VIMS population surveys.

Launched in 1955, the VIMS juvenile finfish trawl survey is the oldest continuous monitoring program of its kind in the U.S. The survey tracks trends in the abundance of a host of important finfish, such as summer flounder and black sea bass, as well as invertebrates like the blue crab.

Helmed by either Brooks or fellow boat captain and scientist Wendy Lowery, the research vessel Fish Hawk is on the water every month. From the deck of the 29-foot trawler, the crew hauls in samples from more than 100 sites in the Chesapeake, Rappahannock, York and James. If you’ve never seen a trawl, it’s “like dragging a big mesh bag behind the boat, along the floor of the bay or the riverbed,” explains Troy Tuckey, one of the co-managers of the survey. “We hit 1,224 stations a year, and we’re out every month.”

Over the years, the trawl has hauled up more than 225 different species of finfish, and over 140 different species of invertebrates. Collecting information on such a wide array of species for more than 50 years “allows us to monitor changes in the bay over time,” Tuckey says.

Fabrizio, the other co-manager of the trawl survey agrees. “In order to set goals for what the Chesapeake fisheries should look like, you need to know what the bay looked like in the past, how the bay has changed and how fish populations have responded to those changes.”

Because the trawl survey is on the water every month, it can serve as an early warning system for changes in the bay. “We help to identify the outbreak of harmful algal blooms,” Tuckey says, “and we’re often the first to identify invasive species. For example, we’ve seen a sharp rise in the population of blue catfish since the late 1990s, which is significant concern for fisheries managers.”

Blue catfish are not native to Virginia waters, and they’ll eat anything and everything. “They’re vacuum cleaners with fins,” says Machut. To make matters worse, they live for an extremely long time—up to 25 years—and can grow to weigh over 100 pounds.

“Blue catfish throw the ecosystem out of balance,” says Fabrizio. “They consume native species, like shad and freshwater mussels, and they out-compete native fishes like white catfish for prey.” The fact that new predators like blue catfish are affecting fish populations is important information for the regulators who are tasked with supporting Virginia’s fisheries. And the VIMS surveys are where that information comes from.

In fact, the fisheries scientists at VIMS “provide us, the state’s fishery managers, with the biological science that helps us to set season, size and creel limits for more than 50 species,” says VMRC’s Bull. “The knowledge that VIMS acquires is beyond measure for us. It’s the cornerstone of sustainable fisheries in Virginia.” And beyond.

The seine and trawl surveys also support many other research efforts. Researchers from up and down the Atlantic seaboard call on VIMS to collect water and animal samples. “Everything from jellyfish to herring,” Tuckey says.

But what if fishing limits aren’t enough? How can we restock flagging fish populations, or ensure that the fish we eat aren’t lost forever? One way is to grow them ourselves.

<< PLANNING FOR THE FUTURE

Just down the hill from VIMS’ research buildings, only feet (and maybe inches) above the York River, is an old greenhouse filled with large circular tanks. You wouldn’t know by looking at them, but those tanks may change the future of the seafood industry.

Each tank is teeming with Atlantic spadefish, a striped fish shaped like the head of a shovel that usually weighs in at around two to three pounds (though they can reach sizes of 14 pounds or more). And Dan Sennett spends a lot of time studying them. Sennett is a marine aquaculture specialist at VIMS, which means that he focuses on how to breed and raise saltwater fish in captivity. He’s a fish farmer.

There are three reasons that aquaculture research is important, Sennett explains. “Raising a fish species in captivity gives us an opportunity to learn more about their development and life cycle. We can also determine whether a species can be raised for consumption, whether it can be done in an environmentally sensitive way, and whether it is cost effective,” Sennett says. “And aquaculture can also make it possible to re-stock wild populations that are at risk.”

For years, aquaculture research at VIMS focused on cobia, a popular fish with recreational anglers that also makes for great eating. VIMS was the first aquaculture facility in the U.S. to successfully breed cobia in captivity, and its work has led to commercial cobia hatcheries around the world. But in 2008, Sennett began working to better understand how to successfully breed and raise spadefish. In many ways, the spadefish seems an ideal candidate. For one thing, Sennett says, “anyone who’s eaten one finds them to be delicious.” Market viability is an important attribute, and a tasty new source of seafood is always welcome. Not only would it be good news for diners, but it would help take the pressure off of wild fish populations. Still, there’s more to it than that.

“Spadefish are able to thrive on a varied diet,” Sennett says. “Hopefully, that will allow us to feed them more plant proteins, such as soy, rather than traditional high-protein feeds,” which are more expensive and have a greater environmental impact, since they’re often made of ground shrimp or fish.

Spadefish in the wild can be found from Massachusetts to Brazil, so they can tolerate a fairly broad range of salinity and temperature. That means they could be cultivated at fish farms in a variety of locations.

And, not incidentally, they’re schooling fish; they actually enjoy swimming together in large groups. That’s an important attribute, since one problem researchers found with raising cobia was that the solitary predators would often eat one another.

Ultimately, Sennett’s goal is to publish a manual that will give detailed step-by-step instructions for raising spadefish from the egg through to maturity, and then breeding the adults. “We call it ‘closing the life cycle,’” Sennett says.

Once the manual is out, we may find spadefish a regular sight on the seafood aisle, but it may have important ecological repercussions as well.

“There’s a lot of uncertainty about spadefish population numbers in the wild,” Sennett says. South Carolina, for example, has already seen their numbers dwindle and has listed them as a “species of concern.” For Sennett, that only makes his work more important. “Anything we can learn about this species could help us ensure their survival,” he says.

And ensuring the survival of Virginia’s diverse fish species is what VIMS is all about.

VIMS.edu

October 15, 2012

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