Scientists study whale-ship collisions

From SFGate: Scientists study whale-ship collisions

Channel Islands, Calif. --

Natalie Senyk and Ben Waltenberger peered out the bubble-shaped windows of the small research plane flying 1,000 feet over the Channel Islands National Marine Sanctuary and scanned the ocean surface for signs of life.

On that bright, windy day earlier this month, the federal scientists were looking, in particular, for blow holes or the gigantic, gray outline of surfacing whales.

The aerial survey is part of a National Oceanic and Atmospheric Administration mission to learn more about the movement of whales and to devise ways to keep them away from the container ships, fishing vessels, barges and sailboats that have been colliding with them at a rate of six a year in California.

In the last few years, NOAA scientists keeping tabs on the marine mammals and ships that share these waters off the coast of Santa Barbara have noticed a troubling trend: Endangered blue, fin and humpback whales have been congregating to feast on krill along a steep, underwater drop-off north of Santa Cruz and Santa Rosa islands.

That feeding ground overlaps with the Santa Barbara Channel's southbound shipping lane, part of a marine highway for cargo ships ferrying goods to and from the sprawling Los Angeles-Long Beach port complex.

The Santa Barbara Channel has been less congested over the last two years, as most freighters have navigated around the traditional shipping lane to avoid the state's strict air pollution curbs. But the decision in June by California regulators to expand the clean-fuel zone beyond the Channel Islands is expected to again concentrate ship traffic in the channel.

And, as on any freeway, more traffic - vessels as well as whales - can have deadly consequences.

Researchers continue to study whether ship strikes significantly threaten West Coast populations of endangered whales. Fin whale and humpback casualties worry them, but blue whales - which had been hunted to the brink of extinction by the 1960s-are their greatest concern.

Over the last decade, dozens of collisions have seriously injured or killed whales off the California coast, and scientists think the population of about 2,500 blue whales that migrates along the West Coast each year may be especially at risk from ship strikes.

But there is an array of challenges in keeping whale and watercraft apart.

The whales are difficult to spot from the bridge of a fully loaded container ship, particularly at night, say those in the shipping industry. And getting a weighed-down vessel the length of several football fields to stop or move out of the way is a tall order. Authorities often don't find out about an accident until a carcass washes ashore with propeller injuries or a ship comes to port with a dead whale pinned to its bow.

Mariners share the concern of wildlife officials and environmental groups, said Dick McKenna, executive director of the Marine Exchange of Southern California, which monitors all vessel traffic in and out of the Los Angeles and Long Beach ports. "Nobody wants to hit a whale," he said.

"The whales are the kids that run out in traffic; that's a way to look at it," said McKenna, a retired U.S. Navy captain who is also a member of the Channel Islands sanctuary's advisory council. "You try to tell kids not to jump out there, but of course, we have no control over the whales."

Indeed, cetacean experts, such as John Calambokidis of the Olympia, Wash., nonprofit Cascadia Research, have found no evidence that blue whales - which can reach a third of a football field in length - are even inclined to move out of the way of the enormous ships as they pass. They may, in fact, be drawn to them.

"They've always been the largest thing in the water and don't seem to be particularly adapted to actively avoiding ships," said Chris Mobley, superintendent of the Channel Islands National Marine Sanctuary. "The burden is really on ships to be prudent: to watch for whales and avoid them. Because the whale is not going to avoid them."

While nearly 100 ship collisions with whales have been reported off the California coast since 1982, the actual number is thought to be much higher. Many go unreported, and experts think a lot of the carcasses sink or drift offshore and decompose, leaving no evidence behind. Large container ships dwarf even blue whales, the largest animals on earth, and may run into the mammals without anyone aboard even knowing.

The precise, real-time movements of large ships rumbling past the Channel Islands is tracked automatically by an apparatus on top of Santa Cruz Island.

The whereabouts of the whales are less understood. That is why researchers have been recording the locations of whales here since 1997. The surveys are timed for the annual Southern California migrations, usually from May to December.

More recently, NOAA has used the whales' coordinates to issue notices asking large vessels to slow down to 10 knots - about half their usual speed. But those notices have gone mostly unheeded, according to vessel-tracking data, NOAA says.

Environmental groups, citing at least five whale fatalities off California in 2010, have urged the government to do more to protect whales. In June they petitioned the Obama administration to establish a mandatory speed limit for large vessels traveling through the Channel Islands and California's three other national marine sanctuaries, an idea the shipping industry opposes.

So far, NOAA has not required any speed restrictions. But officials have been talking with the shipping industry about voluntary measures to reduce ship strikes. The Pacific Merchant Shipping Assn., a trade group representing ocean carriers, is backing a proposal before the U.S. Coast Guard to shift the southbound shipping lane away from the area favored by the whales.

On a recent survey flight, a small crew of researchers flew slowly over the rugged islands. They crossed the 60-mile archipelago four times, from tiny, craggy Anacapa Island closest to the shoreline, to remote San Miguel Island on the western end.

With their naked eyes or binoculars, they spotted whales and dozens of vessels, from colossal barges and cargo ships to the smallest sailboats and kayaks. Using an angle-measuring instrument called an inclinometer, they noted the location of each one.

Three hours into the flight, Waltenberger sighted the blow hole of a whale spewing mist above the surface. But almost as soon as it appeared, the creature slid back into the deep.

Five minutes later they saw a blue whale rise to the surface, its immense outline parting the clear, blue seawater before it dived out of view.

The scientists say data collected in the aerial surveys will help the government predict where the whales are most likely to emerge from the depths and could ultimately be used to write regulations to reduce the likelihood of boats and whales crossing paths.

"The goal is to collect information that's needed so these whales that were hunted almost to extinction can be taken off the endangered species list," Senyk said. While it's up to policymakers to decide how to keep whales and ships apart, she said, researchers know "there's an intrinsic and ecosystem value to these species.

"We want both to coexist," she said.