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Gray Whales (Eschrichtius Robustus) Off Sakhalin Island, Russia: Seasonal And Annual Patterns Of Occurrence, David Weller, Bernd Wursig, Amanda Bradford, Alexander Burdin, Sergey Blokhin, Hiroya Minakuchi, Robert L. Brownell Jr.
Gray Whales (Eschrichtius Robustus) Off Sakhalin Island, Russia: Seasonal And Annual Patterns Of Occurrence, David Weller, Bernd Wursig, Amanda Bradford, Alexander Burdin, Sergey Blokhin, Hiroya Minakuchi, Robert L. Brownell Jr.
United States Department of Commerce: Staff Publications
The annual return, seasonal occurrence, and site fidelity of Korean-Okhotsk or western gray whales on their feeding grounds off northeastern Sakhalin Island, Russia, were assessed by boat-based photo-identification studies in 1994-1998. A total of 262 pods were observed, ranging in size from 1 to 9 whales with an overall mean of 2.0'. Sixty-nine whales were individually identified, and a majority of all whales (71.0%) were observed in multiple years. Annual sighting frequencies ranged from 1 to 18 d, with a mean of 5.4 d. The percentage of whales re-identified from previous years showed a continuous annual increase, reaching 87.0% by …
Data Fusion For Use Of Passive Microwave Data In Operational Sea-Ice Monitoring, Kim Partington, Mary-Ruth Keller, Paul Seymour, Cheryl Bertoia
Data Fusion For Use Of Passive Microwave Data In Operational Sea-Ice Monitoring, Kim Partington, Mary-Ruth Keller, Paul Seymour, Cheryl Bertoia
United States Department of Commerce: Staff Publications
A new SSM/I algorithm is described that is based on near real-time data fusion with portions of operational ice charts derived from RADARSAT, OLS or AVHRR data. The aim of this is to enable parts of the ice chart where there is no cloud-free imagery or SAR data to be completed using an SSM/I algorithm that is tuned to the region and time associated with the ice chart. The algorithm is a linear combination of partial concentrations from the NASA Team and Bootstrap algorithms together with lower variance principal components of SSM/I data. The algorithm is designed for near real …
Hunting And Social Behaviour Of Leopard Seals (Hydrurga Leptonyx) At Seal Island, South Shetland Islands, Antarctica, Lisa M. Hiruki, Michael K. Schwartz, Peter L. Boveng
Hunting And Social Behaviour Of Leopard Seals (Hydrurga Leptonyx) At Seal Island, South Shetland Islands, Antarctica, Lisa M. Hiruki, Michael K. Schwartz, Peter L. Boveng
United States Department of Commerce: Staff Publications
The hunting behavior of leopard seals Hydrurga leptonyx was monitored opportunistically at Seal Island, South Shetland Islands, during the austral summers from 1986/87 to 1994/95. Leopard seals used several methods to catch Antarctic fur seal pups Arctocephalus gazella and chinstrap penguins Pygoscelis antarctica, and individuals showed different hunting styles and hunting success. One to two leopard seals per year were responsible for an average of 60% of observed captures of fur seal pups. Leopard seals preyed on penguins throughout the summer, but preyed on fur seal pups only between late December and mid-February. Hunting behavior differed significantly between different …
Sensitivity Of Fish Embryos To Weathered Crude Oil: Part Ii. Increased Mortality Of Pink Salmon (Oncorhynchus Gorbuscha) Embryos Incubating Downstream From Weathered Exxon Valdez Crude Oil, Ron A. Heintz, Jeffrey W. Short, Stanley D. Rice
Sensitivity Of Fish Embryos To Weathered Crude Oil: Part Ii. Increased Mortality Of Pink Salmon (Oncorhynchus Gorbuscha) Embryos Incubating Downstream From Weathered Exxon Valdez Crude Oil, Ron A. Heintz, Jeffrey W. Short, Stanley D. Rice
United States Department of Commerce: Staff Publications
We incubated pink salmon embryos under three exposure conditions, direct contact with oil-coated gravel, effluent from oil-coated gravel, and direct contact with gravel coated with very weathered oil (VWO). Embryo mortalities and polynuclear aromatic hydrocarbon (PAH) accumulation in embryo tissues during the direct-contact and effluent exposure experiments were not significantly different, indicating that PAH accumulation was mediated by aqueous transport. Mortality rates for embryos exposed initially to a total PAH concentration (TPAH) of 1.0 ppb were significantly higher than controls when the PAH were derived from VWO. The same aqueous TPAH concentration failed to increase mortality rates when the PAH …
Development Of Regional Climate Scenarios Using A Downscaling Approach, David Easterling
Development Of Regional Climate Scenarios Using A Downscaling Approach, David Easterling
United States Department of Commerce: Staff Publications
As the debate on potential climate change continues, it is becoming increasingly clear that the main concerns to the general public are the potential impacts of a change in the climate on societal and biophysical systems. In order to address these concerns researchers need realistic, plausible scenarios of climate change suitable for use in impacts analysis. It is the purpose of this paper to present a downscaling method useful for developing these types of scenarios that are grounded in both General Circulation Model simulations of climate change, and in situ station data. Free atmosphere variables for four gridpoints over the …
Evidence Of A Feeding Aggregation Of Humpback Whales (Megaptera Novaeangliae) Around Kodiak Island, Alaska, Janice Waite, Marilyn Dahlheim, Roderick Hobbs, Sally Mizroch
Evidence Of A Feeding Aggregation Of Humpback Whales (Megaptera Novaeangliae) Around Kodiak Island, Alaska, Janice Waite, Marilyn Dahlheim, Roderick Hobbs, Sally Mizroch
United States Department of Commerce: Staff Publications
The known summer feeding range of the North Pacific humpback whale (Megaptera novaeangliae) extends from California, along the coasts of Oregon, Washington, and Alaska, into the Bering Sea, along the Aleutian Islands, the Sea of Okhotsk (Tomilin 1957), and to northern Japan (Rice 1977). In feeding areas of the northeastern Pacific Ocean, humpback whale photoidentification research has been concentrated off California (Calambokidis et al. 1993), southeastern Alaska (Darling and McSweeney 1985, Baker et al. 1986, 1992; Perry et al. 1990), Prince William Sound in Alaska (von Ziegesar 1992), the Oregon and Washington coasts (Calambokidis et al. 1993), and …
Baleen Whales: Conservation Issues And The Status Of The Most Endangered Populations, Phillip Clapham, Sharon Young, Robert L. Brownell Jr.
Baleen Whales: Conservation Issues And The Status Of The Most Endangered Populations, Phillip Clapham, Sharon Young, Robert L. Brownell Jr.
United States Department of Commerce: Staff Publications
Most species of baleen whales were subject to intensive overexploitation by commercial whaling in this and previous centuries, and many populations were reduced to small fractions of their original sizes. Here, we review the status of baleen whale stocks, with an emphasis on those that are known or thought to be critically endangered. Current data suggest that, of the various threats potentially affecting baleen whales, only entanglement in fishing gear and ship strikes may be significant at the population level, and then only in those populations which are already at critically low abundance. The impact of some problems (vessel harassment, …
Evaluation Of Special Sensor Microwave / Imager Sea-Ice Products, Kim Partington, Cheryl Bertoia
Evaluation Of Special Sensor Microwave / Imager Sea-Ice Products, Kim Partington, Cheryl Bertoia
United States Department of Commerce: Staff Publications
Existing SSM/I algorithms are imperfect at mapping total and partial ice concentrations. This paper reviews recent findings based on comparisons of sea-ice products against other satellite data and U.S. National Ice Center (NIC) ice charts.