North pacific research board sperm whales

The Journal of the Acoustical Society of America, Sperm whales have depredated black cod Anoplopoma fimbria from demersal longlines in the Gulf of Alaska for decades, but the behavior has recently spread in intensity and geographic coverage. latitudinal, were tested using whaling operation data, results of recent sighting cruises, and movements of marked whales.

SPERM WHALE Physeter macrocephalus

The information is also helpful for future In-depth Assessment (IA) of this species by the International Whaling Commission Scientific Committee (IWC SC). None of these characteristics, however, saved sperm whales from human greed. Sperm whales have learned to take sablefish off longline gear in the Gulf of Alaska.

Sperm whales have learned to take sablefish off longline gear in the Gulf of Alaska. In the North Pacific Ocean, sperm whales were depleted by extensive commercial whaling over a period of more than a hundred years, and the species was the primary target of illegal Soviet.

This study synthesizes National Marine Fisheries Service observer data, National Marine Fisheries Service sablefish longline survey and fishermen-collected depredation data to: 1 estimate the frequency of killer whale depredation on longline fisheries in Alaska; 2 estimate depredation-related catch per unit effort reductions; and 3 assess direct costs and opportunity costs incurred by longliners in western Alaska as a result of killer whale interactions.

Improved abundance and trend

Sperm whales are an endangered species and little is known about their population size and structure in the North Pacific. Fishermen change their fishing practices to avoid depressed catch rates associated with depredating whales, but these changes can be costly for the fleets.

Testing longline hooks in the mouths of marine mammals McLellan, W. Killer whale Orcinus orca depredation effects on catch rates of six groundfish species: implications for commercial longline fisheries in Alaska. The objective of the stock structure part of JARPNII survey for sperm whales is to obtain information useful for describing stock structure of sperm whales inhabiting the western North Pacific.

Learn more about current opportunities and other ways you can get involved with us. Mortality and serious injury of sperm whales has occurred in other areas of the world due to similar fisheries interactions. Two contrary opinions on the segregation pattern of sperm whale stocks in the North Pacific, i.e.

The percentage of commercial fishery sets affected by killer whales was highest in the Bering Sea fisheries for: sablefish Average catch per unit effort reductions on depredated sets ranged from This assessment of killer whale depredation costs represents the most extensive economic evaluation of this issue in Alaska to date and will help longline fishermen and managers consider the costs and benefits of depredation avoidance and alternative policy solutions.

This research incorporates mixed methods to evaluate: 1 spatio-temporal depredation trends, 2 depredation effects on groundfish catch rates, and 3 socio-economic implications of depredation avoidance and changing fishing practices due to whale interactions.

These measures employed by the fleet are moderately effective at whale avoidance but are generally considered short-term fixes for a long-term problem. Sperm whales are an endangered species and little is known about their population size and structure in the North Pacific.

longitudinal vs.

A note on the

We use mitochondrial DNA (mtDNA) ( bp), six microsatellites and 36 single-nucleotide polymorphisms (SNPs), 20 of which were linked, to investigate population structure of sperm whales (Physeter macrocephalus) in the eastern and central North Pacific.

Through cooperative research with fishermen, government, and scientists our ultimate goal is to provide recommendations for strategies to reduce or eliminate depredation on longline gear by sperm whales. Scientists with the Center's National Marine Mammal Laboratory (NMML) report on the former U.S.S.R's illegal whaling of this species, which was conducted secretly and on a massive scale, with size limits and other regulations largely ignored.

These interactions increase direct costs and opportunity costs associated with catching fish and reduce the profitability of longline fishing in western Alaska. Journal of Experimental Marine Biology and Ecology, Avoiding killer whale depredation in Alaskan longline fisheries Megan Peterson University of Alaska Killer whale Orcinus orca depredation occurs when whales damage or remove fish caught on longline gear.

These results provide insight into the potential impacts of killer whale depredation on fish stock abundance indices and commercially important fisheries in Alaska and will inform future research on apex predator -fisheries interactions.

Sperm Whale Population Structure

Effects on shortspine thornyhead Sebastolobus alascanus catches were not significant in any management area p. SNP markers, reproducible across technologies and laboratories, are ideal for long-term studies of globally distributed species such as sperm.

This depredation of longline gear by sperm whales has increased since the mid s, likely due to the lengthening of the fishing season. Killer whale Orcinus orca depredation occurs when whales damage or remove fish caught on longline gear. To browse Academia.

STOCK DEFINITION AND GEOGRAPHIC RANGE The sperm whale is one of the most widely distributed marine mammal species, perhaps exceeded in its global range only by the killer whale and humpback whale (Rice ). As a first step, inwe collected information, with collaboration from the fishing fleet, on the timing of int Killer whale Orcinus orca depredation whales stealing or damaging fish caught on fishing gear adversely impacts demersal longline fisheries for sablefish Anoplopoma fimbriaPacific halibut Hippoglossus stenolepis and Greenland turbot Reinhardtius hippoglossoides in the Bering Sea, Aleutian Islands and Western Gulf of Alaska.

This study uses National Marine Fisheries Service longline survey data from to explore spatial and temporal trends in killer whale depredation and to quantify the effect of killer whale depredation on catches of six groundfish species within three management areas in Alaska: the Bering Sea, Aleutian Islands and Western Gulf of Alaska.

NORTH PACIFIC RESEARCH BOARD

The North Pacific Research Board offers competitive marine science funding for each of our research programs. Further, depredation has created economic loss to fishermen and presents fisheries managers with a difficult assessment problem, because the amount of sablefish mortality due to depredation is unknown.

This depredation of longline gear by sperm whales has increased since the mid s, likely due to the lengthening of the fishing season.