09-10-2010, 11:10 AM
WASHINGTON, Sept. 8 (UPI) -- A U.S. agency says it is designating the eastern North Pacific basking shark a "species of concern" due to a dramatic decline in its population.
The National Oceanic and Atmospheric Administration's Fisheries Service says the shark has been overfished and its population has apparently not responded to conservation measures implemented to address fishing pressure, a NOAA release said Wednesday.
Basking sharks are filter feeders most commonly found in temperate coastal waters where plankton, their main food source, is concentrated.
The eastern North Pacific population of the sharks is thought to be a single group that migrates seasonally along the West Coast from Canada to Central California, NOAA says.
Until the 1950s, commercial fishermen in California targeted the sharks for fish meal and fish oil, and Canadian fishermen targeted them until the 1970s to reduce interactions between the sharks and salmon fishing nets.
Although there has been no commercial fishing pressure for decades, scientists are worried their numbers have not rebounded.
While hundreds, and even thousands, of fish were once observed together, no group larger than three has been reported since 1993, NOAA says.
NOAA's Fisheries Service is working with researchers along the West Coast to tag and track basking sharks, the agency says.
The National Oceanic and Atmospheric Administration's Fisheries Service says the shark has been overfished and its population has apparently not responded to conservation measures implemented to address fishing pressure, a NOAA release said Wednesday.
Basking sharks are filter feeders most commonly found in temperate coastal waters where plankton, their main food source, is concentrated.
The eastern North Pacific population of the sharks is thought to be a single group that migrates seasonally along the West Coast from Canada to Central California, NOAA says.
Until the 1950s, commercial fishermen in California targeted the sharks for fish meal and fish oil, and Canadian fishermen targeted them until the 1970s to reduce interactions between the sharks and salmon fishing nets.
Although there has been no commercial fishing pressure for decades, scientists are worried their numbers have not rebounded.
While hundreds, and even thousands, of fish were once observed together, no group larger than three has been reported since 1993, NOAA says.
NOAA's Fisheries Service is working with researchers along the West Coast to tag and track basking sharks, the agency says.