Out on the hunt for sharks Search: Researchers from the National Aquarium in Baltimore have been in the Delaware Bay this week seeking exotic sea creatures for exhibits.

July 04, 1996|By John Rivera | John Rivera,SUN STAFF

LEWES, Del. -- It had been a dogfish day afternoon for a team of researchers from the National Aquarium in Baltimore.

On the fourth day of a weeklong Delaware Bay expedition hunting for sharks and other exotic sea creatures, four marine biologists kept pulling up the apparently uninteresting and toothless dogfish shark -- 15 of them to that point. They frowned and tossed all of them back.

The aquarium staff comes to the Delaware Bay each year in search of sandbar sharks to add to its collection and to release sandbar sharks that have become too big and too aggressive to keep in the tank with smaller fish.

Releasing the sharks is easy. Catching new ones is more of a challenge, as members of the expedition would find as the day wore on.

The prized catch, an adult sandbar shark that measures 4 feet or more, big enough to put in an exhibit tank with other large sharks, had proved elusive and the researchers were getting frustrated. They had caught 45 dogfish the previous day -- "woofers" they call them -- and yesterday was looking no better.

On the first line of the day they pulled up it was nothing but dogfish. But on the last of the 45 hooks on this 1,800-foot ground fishing line excitement suddenly built. It was a keeper.

"Something here," said Perry Hampton, 38, assistant curator of fishes at the National Aquarium, as he pulled up the line and the distinctive shape came into view. "It's a ray."

"It's a roughtail," said aquarist Jason Crichton, 25, standing next to him on the deck of the aquarium's 23-foot research vessel.

A female roughtail stingray would be a great find, a complement to the male already in the aquarium collection. At first it looked like it might be female. But then the researchers pulled the stingray into the boat in a red canvas stretcher and got a closer look.

"It's a male," Crichton said.

"That's OK," Hampton said. "We'll keep him anyway."

Yesterday was a kind of trade-off for the aquarium. Scientists took the stingray, but earlier had released the two sandbar sharks, known by their aquarium names of CP-95-1 and CP-95-2, which designate their species and when they were caught.

They were released because they were just getting too big.

"They started to get aggressive," said Hampton. "They took food from other animals. They became a threat to the other animals and to the [aquarium volunteer] divers as well."

About 8 a.m., under an overcast sky and in dark choppy waters about two miles from shore, the sharks were released. They had been loaded into a tank on the aquarium boat for the ride out. Hampton and Crichton lifted each shark carefully out of the water -- unlike dogfish sharks, sandbars have a fine set of teeth -- and set it gently into the water.

"There you go, buddy," Hampton said as the first shark went into the water. Almost immediately it swam out of sight.

"That was kind of anti-climatic," Hampton said, possibly noticing the "Is that all there is?" look in the eyes of some visitors on the boat. Not that he was complaining.

"Excitement is bad," he said. When handling sharks, "We don't like excitement."

In the afternoon, the crew again went looking for the big sandbar shark. To attract the fish, they used an 1,800-foot weighted line with 45 smaller lines, each about 6 feet long, attached. At the end of each of the short lines was a hook with mackerel bait.

The aquarium staff trolls the Delaware Bay because it is sort of a sandbar shark nursery. In the early summer months, female sandbars come into the shallow coastal waters to give birth to their pups.

"Males stay out in the deep water," Hampton said. "It's a way of protecting the young, because males would cannibalize the pups."

The clouds broke and the sun started to shine. The mood of the crew perked up as they pulled in a line they had laid about a half-mile from shore. The sandbars were biting.

Aquarist Matt Ankley, 27, steered the boat and recorded data as aquarist trainee Linda Hanna, 26, pulled in the line. Hampton and Crichton removed the hooks from the fish and rebaited them.

The first short line they pulled in had a sandbar shark attached, the first of the day. Hampton pried the shark's mouth open with a blue plastic tool and used a pair of needle-nosed pliers to take out the hook. Crichton called out the measurements -- the shark was 102 centimeters long -- and Ankley at the helm recorded them on a clipboard.

This shark was too small to keep. They took measurements and fitted the shark with a National Marine Fisheries Service tag. The information they recorded, including sex, length and where and when it was caught, will be added to the fisheries service database. If the shark is caught again and measured, it will yield information on growth and migration patterns.

As Hampton worked the hook free, he was careful to keep his fingers from the shark's mouth. Working with the animals doesn't scare him. "But if this was a snake, I'd be on the other side of the boat," he said.

Finally, after about 10 hours on the water, they found their prize: a 5-foot, 5-inch female sandbar shark.

"This is it," Hampton said. "This is exactly what we've been looking for."

Even though they got what they came for, such sharks are becoming harder and harder to find because of overfishing, Hampton said. He noted that it takes 20 years for sharks to reach sexual maturity, they mate only every other year and bear just five or six pups at a time.

"It's very easy to impact a population by catching too many of them and it's very difficult for the population to recover," he said.

"They haven't been listed as threatened yet. But believe me, they are."

Pub Date: 7/04/96

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