The number of sightings in Hawaii waters of humpback whales entangled in fishing lines, nets and other marine debris has more the doubled during the current migration season, reaching a record high of 14, according to federal marine officials.
At a news conference Friday at Keehi Lagoon, officials asked boaters to be on the lookout for two entangled humpbacks spotted in the past week.
One of the whales was swimming Monday off southwest Kauai with a line cutting into its tail fluke, which can be a life-threatening situation, said David Schofield, manager of the National Oceanic and Atmospheric Administration’s Regional Marine Mammal Health and Response Program.
The condition of the other humpback sighted in waters off Olowalu in West Maui remained unknown, Schofield said.
Humpback whales are federally endangered species, but have been making a comeback in Hawaii in recent years.
From November through May, their seasonal migration from Alaska brings an estimated 10,000 to 12,000 humpbacks to Hawaii waters — a large jump from the 1,000 estimated in 1978.
During the November 2012-May 2013 season, there were six sightings of entangled whales.
The entire North Pacific humpback whale population, estimated at 20,000, has been increasing at a rate of 7 percent annually due to federal protections for the endangered species, according to scientists.
Scientists monitor the 45-ton winter visitors as they mate and nurse their young in the Hawaiian Islands Humpback Whale National Marine Sanctuary, which lies within the shallow (less than 600 feet) warm waters surrounding the main Hawaiian Islands.
Schofield said most of the entanglements are caused by marine debris lines. He asks boaters who discover an entangled whale to call the federal hotline 888-256-9840 and, if possible, to stay with the whale until authorities are able to find the distressed creature.
"That’s the best thing you can do — report on it, then stay with it," Schofield said.
He warns boaters against trying to disentangle a whale themselves, noting that rescues are dangerous and attempting one without the proper know-how can diminish the chances of saving the whale. For example, Schofield said, a few weeks ago some people cut a buoy line dragging behind a whale, making it difficult to see that the whale was still entangled around the body.
Whale rescue crews sometimes tag the lines with other material to slow the whale enough so that cutting the lines around the body is easier.
Ed Lyman, the large whale entanglement response coordinator for the marine sanctuary, said to some degree, the number of sightings are increasing because the scope of reporting is broadening and more reports are coming from tugboat captains and fishermen.
Lyman said the number of successful entangled-whale rescues have increased from one last season to two so far this season.
During a rescue, underwater pole cams are used to see the condition of the whale, and special poles with knives are used to cut the lines.
Trying to disentangle a humpback whale can be complicated by the presence of other whales. A mother may be traveling with a calf and an escort, "So you’re not just dealing with one whale," Lyman said. "You’re dealing with three whales. … People can be seriously injured by these whales."
