May 29, 2012

By Joseph Castro

Earlier this month, a young gray whale became entangled in two sets of commercial crab pot lines off the coast of San Francisco. Luckily for the whale, rescuers were able to free it successfully. Not all stories have a happy ending —fishing nets kill over 300,000 small whales, dolphins and porpoises each year, according to the World Wildlife Fund. Now, a new multi-agency project, dubbed WhaleWatch, hopes to reduce the number of whales accidentally killed by fishing nets and ship strikes by first determining high-risk areas that the marine mammals are likely to visit.

“We want to understand where the animals are going and why they are going there,” said WhaleWatch project leader Helen Bailey, a biologist at the University of Maryland. “We are using the best satellite data we have to develop habitat models to reduce ship entanglements and strikes and hopefully change shipping lanes.”

Gray whales, along with several other whale species, have migration patterns that run along the West Coast of the United States. Gray whales get entangled in fishing nets along the West Coast of the United States more than any other whale species, possibly as a result of their long migration route, Bailey explained. The whales feed in the arctic seas near Alaska during the summer and breed in the warmer waters of Mexico in the winter.

Fishing nets pose one of the greatest dangers to whales, but other threats such as passing ships exist as well. “We don’t actually see the animals get struck, but when they get stranded, marks on the animals infer that they were hit by a ship,” Bailey explained.

To prevent such accidents from happening in the future, Bailey and her colleagues at Oregon State University and the National Oceanic and Atmospheric Administration (NOAA) are analyzing the migration patterns of gray whales, as well as the endangered blue, fin and humpback whales. Researchers have already tagged over 300 whales — the tags transmit position data to overhead satellites each time the whales come to the surface for air. With the tags, the scientists have now collected migration data for 1993 through 2009.

“We already have the tracking data but it’s in a raw form,” Bailey explained. “We are using state of the art modeling to get the best estimates of the whales’ daily positions.” Combining this information with environmental data, such as sea-surface temperature, will help Bailey and her team further understand where the whales travel.

The next step will be to add a human component to figure out specific actions we can take to help protect these animals. Scientists with NOAA have data on shipping and fishing lanes, and details about the paths of specific ships, Bailey said. “NOAA can put together our data with the data they have on shipping and fishing to see where they overlap,” she said. “Where are the areas that are most concerning?”

Policymakers will be able to use the information to find better ways to protect whales near the coast.

In addition to preventing whales from getting hit by ships or caught in nets, the project could also help whales that do get tangled, Bailey noted. If a whale gets entangled in a fishing gear but continues to swim, rescuers may have difficulties locating the animal. The new information will help them figure out where the ensnared whale is likely to go.

Right now, the WhaleWatch project is in its first of three years. If successful, the technology and program model can easily be used in other regions to help protect marine mammals, Bailey said.

Top Image: Merrill Gosho, NOAA

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