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Curiosity gets best of them

The bottlenose dolphin has always been known as one of the most playful animals on earth, but biologists now believe these marine mammals may be too curious for their own good.

By TERRY TOMALIN
Published July 25, 2007


The bottlenose dolphin has always been known as one of the most playful animals on earth, but biologists now believe these marine mammals may be too curious for their own good. ¶ Scientist with the National Marine Fisheries Service in St. Petersburg watched how dolphins interacted with recreational fishermen on the Sunshine Skyway Fishing Piers for 10 days this spring. ¶ During that time period, the biologists observed 141 dolphin-human interactions. ¶ In 99 cases, the dolphin succeeded in stealing the fisherman's bait; in 37 cases, the dolphin was able to snatch the angler's catch. ¶ "This is a big problem because dolphins are getting hooked," said Stacey Carlson, a NMFS biologist. ¶ "This has been a historical problem on the commercial side, but this is the first time we are seeing it with recreational fishermen."

Dolphin deaths

The number of bottlenose dolphin found stranded or dead because of fishing gear is on the rise throughout Florida. In 2006, biologists with Sarasota's Mote Marine Laboratory found five dolphins with some kind of fishing gear still attached.

Four of the animals died as a result - three adults that had eaten lures, hooks and line, and one calf that nearly had its tail severed by a piece of fishing line. The four dolphins were well known to the Mote scientists; they had been observing one of them for 22 years. In 2005, Mote researchers found just one dolphin that had been entangled in fishing line.

The problem is just as bad on Florida's East Coast. Last year, biologists with the Hubbs-Sea World Research Institute in Orlando recovered six dead dolphins that showed injuries caused by fishing gear.

 

Don't feed the animals

Biologists suspect the dead dolphins had lost their natural fear of humans because they had been fed by fishermen or boaters. Over time, bottlenose dolphins have learned that humans mean an easy meal.

"This has changed their behavior," Carlson said. "Now they have learned to steal bait from fishermen."

Dolphins are protected by federal law. Feeding and harassment of wild dolphin is a crime. What do federal officials consider harassment? It means, "Any act of pursuit, torment or annoyance that has the potential to injure or disrupt the behavior of wild marine mammals."

 

Ongoing problem

Thieving dolphins has become such a problem in areas such as the Indian River Lagoon, Charlotte Harbor and Sarasota and Tampa bays that biologists have come up with a scientific term to describe this behavior: dolphin depredation.

Dolphins are quite adept at depredating, or stealing both bait and catch. Most of the time, these cagey animals can get away without getting hooked. But occasionally, the angler's line breaks and the dolphin swims away, and swallows the meal, hook, line and sinker.

Federal officials have numerous examples of fishing tackle that has been removed from the stomachs of dead dolphins.

Don't shoot the dolphin

Most fishermen move on to another fishing spot when dolphins swim into an area. But in October 2005, a charter boat captain from Panama City let his anger get the best of him.

Christopher Kevin Weaver, skipper of the Leo Too, saw a dolphin grab a fish that one of his clients had just caught. Weaver, standing on the bridge, pulled out a .357 caliber handgun and shot at the dolphin. When the dolphin followed his boat to another spot, Weaver fired off several more rounds at the marauding mammals.

In August 2006, Weaver pled guilty to one misdemeanor count of violating the federal Marine Mammal Protection Act, which is punishable by one year in jail and a $100,000 fine.

What you can do

Dolphin will eat just about anything, but in the Skyway study, the mammals, like humans, have an affinity for grouper, mackerel and sheepshead. Federal officials have come up with a list of do's and don'ts to help avoid harmful interaction with bottlnose dolphin.

- Don't toss your leftover bait to dolphin. Take the bait home, put it in your freezer for chum, or give it to a neighbor who is going fishing.

- Check your line to make sure it is in good shape so it won't break easily if you do accidentally hook a dolphin.

- Avoid fishing in areas where dolphins are actively feeding. You are just asking for trouble.

- Do not release fish if there are dolphins nearby. You might as well say, "Hey Flipper, here's a free meal."

- If dolphins move into your fishing area, move.

- Don't use stainless steel hooks. Using something that won't corrode easily. If a dolphin gets hooked, the metal will rust in a matter of days.

. What you can do

Report violations

To report marine mammal violations, such as feeding, touching or chasing wild dolphins, contact the National Oceanic and Atmospheric Administration Fisheries Enforcement Hotline at 1-800-853-1964.

For more information

To learn more about the national Protect Dolphins Campaign, go to www.nmfs.noaa.gov/pr/education/protectdolphins.htm.