By WILLIAM J. BROAD | Senior Science Writer
Perhaps we can save the whales — or at least their hearing.
Scientists have long known that man-made, underwater noises — from engines, sonars, weapons testing, and such industrial tools as air guns used in oil and gas exploration — are deafening whales and other sea mammals. The Navy estimates that loud booms from just its underwater listening devices, mainly sonar, result in temporary or permanent hearing loss for more than a quarter-million sea creatures every year, a number that is rising.
Now, scientists have discovered that whales can decrease the sensitivity of their hearing to protect their ears from loud noise. Humans tend to do this with index fingers; scientists haven’t pinpointed how whales do it, but they have seen the first evidence of the behavior.
“It’s equivalent to plugging your ears when a jet flies over,” said Paul E. Nachtigall, a marine biologist at the University of Hawaii who led the discovery team. “It’s like a volume control.”
The finding, while preliminary, is already raising hopes for the development of warning signals that would alert whales, dolphins and other sea mammals to auditory danger.
Read the rest of the article online in The New York Times.
Fisheries Resources Division
Scientists from the U.S. and Canada are working together to strengthen Pacific sardine stock assessments. SWFSC scientists conduct regular Pacific sardine stock assessments to determine harvest guidelines for this economically important species. In May, Canadian and NMFS scientists, together with independent experts, considered how to integrate data from Fisheries and Oceans Canada’s West Coast Vancouver Island swept-area trawl survey (WCVI) into the Pacific sardine stock assessment.
Preliminary results of the review suggest that including the Canadian survey data could strengthen and enhance the U.S. stock assessment in the future, especially as the survey evolves. Inclusion of the Canadian survey into the assessment may provide valuable insights into the northern most extension of the Pacific sardine population, the largest size classes, and the timing and extent of migration during different years. The Pacific Fishery Management Council will consider whether to incorporate the Canadian data into the U.S. stock assessment based on the independent review results. The earliest the data could be incorporated would be for the 2014 fishing season.
For more information on SWFSC’s coastal pelagic research programs, please visit the Fisheries Research Division
Management information on Pacific sardine in U.S. waters may be found at the Council’s website: http://www.pcouncil.org/coastal-pelagic-species/background-information/
Letters to the Editor
Re “Fisherman agree: Big fish need little fish” (Viewpoints, June 22):
The article omitted key facts the public should understand about California’s fisheries. Appealing to the Pacific Fishery Management Council to “forestall the harvest of forage species that aren’t currently being fished,” the authors cited a Lenfest Forage Fish Task Force study finding that worldwide, forage fish are mostly ground into meal to feed livestock and farmed fish. This is untrue in California. They didn’t point out that according to the same report, we already leave plenty of forage fish in the sea. West Coast forage fisheries harvest only 2 percent of the total forage pool, leaving 98 percent in the ocean. The most important forage species on the West Coast are already well managed. The PFMC recently approved deliberative action, allowing more time for scientific analysis and the development of the most practical, effective management tools. This is a win for all, providing the most cost-effective and timely response to concerns that new fisheries might over-exploit forage species.
— Diane Pleschner-Steele, executive director, California Wetfish Producers Association