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Whales and Entanglements

The Dangerous Job of Disentangling Whales

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Picture Of An Entangled Humpback Whale

A young humpback whale (Megaptera novaeangliae) with a line wrapped around its back. May 2005, Gulf of Maine.

© Blue Ocean Society for Marine Conservation

In July 2009 I attended a talk on large whale disentanglement given by David Morin, who works for NOAA (National Oceanic and Atmospheric Administration) and previously worked for the Provincetown Center for Coastal Studies(PCCS) in Provincetown, MA, an organization which has taken the lead on rescuing entangled whales along the East Coast of the U.S. Entanglement is an important issue in whale conservation, because it is one of the major threats to whales today.

Check out the photos on PCCS's web site, and you might get an idea of what a dangerous job it is to disentangle whales. Imagine approaching a 40-foot humpback whale, who weighs as much as 500 people, and trying to cut off sometimes hundreds of feet of rope that wrap around the animal's tail, flippers or head. It's not a job for an amateur!

While fishermen, conservationists and government agencies are working to prevent entanglements through modifying gear and closing some areas to fishing when whales are present, there are a number of whales entangled each year.

Whale Entanglement Statistics

According to PCCS's web site, in 2007 alone, PCCS addressed 30 cases where whales were entangled. Four of these were right whales who had been reported entangled in previous years. The whales included 11 humpbacks, 6 right whales, 4 fin whales, and 3 minke whales.And these are just the cases that we know about. It's estimated that 10-20% of the population of humpbacks and right whales in the Gulf of Maine acquire new entanglement wounds each year.

How Entanglements Affect Whales

Entanglements can be life-threatening to a whale. According to the PCCS web site, "When these animals become fouled in gear, normal breathing and movement may be impaired or stopped completely. If the animal does manage to struggle free, portions of gear may remain attached to the body. This trailing gear...may create excess drag, snag onto objects in the environment and impede normal behavior like breathing, feeding, movement or breeding. Other effects include infections and deformations."

In New England, the primary gear culprits are gillnets and lobster traps, which have lines near the ocean bottom and lines that attach to buoys at the surface, resulting in multiple potential entanglement points. Gillnets have mesh netting, which the whales could break through, but whales may roll in panic when they feel an unfamiliar substance, causing them to wrap up in the gillnet panels.

Rescuing Whales Is Dangerous

Disentangling whales can be life-threatening to humans. Inexperienced, well-meaning people have died trying to free a whale from a harmful wrap of fishing line. That's why there are less than a dozen people in the U.S. who are authorized to attempt a disentanglement. Whales are huge and unpredictable, and so far, there isn't any indication that the whales know that the team is there to help them. There is also the very real possibility that the rescuer will get trapped in the line entangling the whale, which is especially life-threatening if the whale picks that moment to dive!

A rescue effort is not undertaken lightly. When an entangled whale is reported, there is much assessment that goes on before a disentanglement is attempted. A response is determined necessary only in situations deemed safe enough for humans to attempt a rescue effort. Because many of the animals that are entangled are endangered species, even saving one can make a difference.

Disentanglement Is Not the Solution

Prevention, not disentanglement, is a solution to the problem of whales interacting with fishing gear. Fishermen, scientists and government agencies are working every day to learn how to prevent entanglements in the first place. In Massachusetts, for example, lobstermen have switched the type of line used between their traps. Instead of the traditional floating line, which can loop up into the water column, they now use line that sinks, lessening the risk to whales.

Each disentanglement attempt helps scientists learn more about who's getting entangled and why. The efforts of PCCS and other rescue organizations around the world will hopefully aid in future prevention efforts.

Disentanglement example: Scientists use sedation to free entangled right whale (January 2011) - Click here.

Note: Photo shows a young humpback whale that was anchored by gear and reported in May 2005. More on this whale and its rescue is available at the Provincetown Center for Coastal Studies web site.

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