Hawaiian Seas Are Close Quarters for Whales and Boaters

Greg Kaufman says his whale-watching boat was doing everything by the book: cruising below 13 knots and staying 100 yards from any visible humpback as a crew member scanned the ocean atop a lookout.

Still, it wasn’t enough to prevent the Pacific Whale Foundation vessel from running over a calf that surged from underneath on the morning of March 9.

It was one of seven confirmed encounters -- some probably fatal to the whales -- during the current breeding season, which has set a record for accidents. Since December, when thousands of humpbacks began arriving here from northern waters to mate or give birth, there have been 35 reports of whale entanglements, more than in all three previous seasons combined.

Environmental groups call the trend alarming, but researchers are hopeful that it has more to do with a rebound in the endangered species’ population than with negligent boaters.

“It’s some combination of increasing number of whales and just boats and whales in the same area at the same time,” said Jeff Walters, co-manager of the Hawaiian Islands Humpback Whale National Marine Sanctuary.

The humpback population roaming the North Pacific, estimated at 10,000, is believed to have been growing at annual rate of about 7% since the mid-1990s. As more whales swim to Hawaii from icy feeding grounds off Alaska, Canada, Russia and Japan, boaters find themselves navigating around about 1,000 calves born in Hawaiian waters each year.

“As long as the population continues to get bigger, it’s going to keep happening,” said Joseph Mobley, a professor at the University of Hawaii-West Oahu who researches whales.

About 50 ships are involved in whale watching in Hawaii, carrying 300,000 passengers a year. Between 1975 and 2005, there were 33 reported strikes involving whales and boats among the islands, with no more than three in a single season.

Babies face a greater risk because they must surface more often -- every three to five minutes. But experts say the mothers, who mated here last year, are getting used to the attention and edging closer to the vessels.

“It’s kind of like driving in a school zone,” said David Schofield, a marine biologist at the National Oceanic & Atmospheric Administration.

Humpbacks, which were placed under international protection in 1966, are shielded under federal law. Boaters need to follow an “approach rule” that instructs them to travel below 13 knots, never leave the helm, post a lookout and stay 100 yards from whales.

Kaufman said a boat captain was doing just that when a calf surprised everyone aboard the company’s Ocean Spirit during an educational cruise for local schools at Maalaea Bay in Maui. The case is being investigated.

“No matter how many best practices we put into effect, when one surfaces directly under your boat, there’s nothing you can do about it,” Kaufman said.