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Tuna, turtles
travel ‘transition
zone,’ biologists say

The zone is one topic
to be discussed at a
Fishery Council meeting

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Star-Bulletin staff

A recently discovered 5,000-mile-long ocean front traveled by loggerhead turtles and albacore tuna across the North Pacific will be discussed by fisheries officials at meetings here this week.

The "transition zone chlorophyll front" will be among topics on the agenda for the 16-member Western Pacific Regional Fishery Management Council tomorrow through Friday at the Ala Moana Hotel.

Fishery biologists at the Honolulu Laboratory of the National Marine Fisheries Service discovered the oceanographic feature with satellite and fisheries data.

They found a transition zone located at the boundary between low-chlorophyll subtropical waters and high-chlorophyll subarctic waters.

Loggerhead turtles and albacore tuna travel along the boundary between the two zones in migrations across the North Pacific, the data showed.

Jeffrey Polovina, ecosystem environmental investigations director at the Honolulu Laboratory, disclosed the new ocean feature at recent meetings here of a national science board.

He said the boundary, which varies seasonally, can be identified between an abundant Pacific region to the north and a biological desert to the south.

The area where the zones converge and the waters are mixed is used by turtles and albacore tuna as a migratory feeding habitat across the Pacific, he said.

Longline fishery catch rates appear higher where the front develops, Polovina said.

Other issues before the fishery council are:

LONGLINE: Reviewing the status of the draft environmental impact statement for turtle management, the Hawaii longline observer program and research to reduce turtle catches by longline fishermen.

An order by U.S. District Court Judge David Ezra in August virtually closed the Hawaii longline swordfish fishery until an environmental impact statement is completed. If it is not completed by March, the longline tuna fishery also will be closed until May.

A recommendation will be considered to allow longline fishermen to assist the research by tagging and releasing sea turtles caught accidentally, collect tissue samples and return specimens to port that are killed inadvertently.

FISHERIES: Reviewing a preliminary draft environmental impact statement for the precious coral and bottom-fish fisheries and for crustaceans.

BLUE SHARKS: Hearing an assessment of the blue shark stock, which is expected to indicate the North Pacific population is underexploited and in no danger of being wiped out.

The council approved a quota of 50,000 blue sharks annually for the Hawaii longline fishery, to be adjusted according to data, that is pending approval by the Secretary of Commerce.

ALBATROSS: Considering proposed changes to longline fishery regulations by National Marine Fisheries and the U.S. Fish and Wildlife services because of concerns about the short-tail albatross.

CORAL REEFS: Hearing the status of a draft Coral Reef Ecosystem Fishery Management Plan and actions regarding coral reef management and marine protection in the Northwest Hawaiian Islands.

CARBON DIOXIDE: Hearing concerns by the Scientific and Statistical Committee that a carbon dioxide experiment off the Big Island next summer could affect fishing grounds.

GREEN SEA TURTLE: Hearing recommendations by that committee that studies be done on the recovery of the threatened green sea turtle population in the Pacific islands and a "cultural take" be established if studies indicate an appropriate level.

HAWAIIANS: Considering community development programs to help Pacific islanders participate in fisheries and a proposal to involve native Hawaiians in a Hawaii observer program.