Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 17 of 17

Full-Text Articles in Entire DC Network

The Phylogenetic Relationships And Biogeography Of True Porpoises (Mammalia: Phocoenidae) Based On Morphological Data, Liliana Fajardo-Mellor, Annalisa Berta, Robert L. Brownell Jr., Claudia Boy, R. Natalie Goodall Oct 2006

The Phylogenetic Relationships And Biogeography Of True Porpoises (Mammalia: Phocoenidae) Based On Morphological Data, Liliana Fajardo-Mellor, Annalisa Berta, Robert L. Brownell Jr., Claudia Boy, R. Natalie Goodall

Publications, Agencies and Staff of the U.S. Department of Commerce

Prior studies of phylogenetic relationships among phocoenids based on morphology and molecular sequence data conflict and yield unresolved relationships among species. This study evaluates a comprehensive set of cranial, postcranial, and soft anatomical characters to infer interrelationships among extant species and several well-known fossil phocoenids, using two different methods to analyze polymorphic data: polymorphic coding and frequency step matrix. Our phylogenetic results confirmed phocoenid monophyly. The division of Phocoenidae into two subfamilies previously proposed was rejected, as well as the alliance of the two extinct genera Salumiphocaena and Piscolithax with Phocoena dioptrica and Phocoenoides dalli. Extinct phocoenids are basal to ...


State Of The Arctic October 2006, J. Richter-Menge, J. Overland, A. Proshutinsky, V. Romanovsky, L. Bengtsson, L. Brigham, M. Dyurgerov, J.C. Gascard, S. Gerland, R. Graversen, C. Hahaas, M. Karcher, P. Kuhry, J. Maslanik, H. Melling, W. Maslowski, J. Morison, D. Perovich, R. Przybylak, V. Rachold, I. Rigor, A. Shiklomanov, J. Stroeve, D. Walker, J. Walsh Oct 2006

State Of The Arctic October 2006, J. Richter-Menge, J. Overland, A. Proshutinsky, V. Romanovsky, L. Bengtsson, L. Brigham, M. Dyurgerov, J.C. Gascard, S. Gerland, R. Graversen, C. Hahaas, M. Karcher, P. Kuhry, J. Maslanik, H. Melling, W. Maslowski, J. Morison, D. Perovich, R. Przybylak, V. Rachold, I. Rigor, A. Shiklomanov, J. Stroeve, D. Walker, J. Walsh

Publications, Agencies and Staff of the U.S. Department of Commerce

This State of the Arctic Report presents a review of recent data by an international group of scientists who developed a consensus on the information content and reliability. The report highlights data primarily from 2000 to 2005 with a first look at winter 2006, providing an update to some of the records of physical processes discussed in the Arctic Climate Impact Assessment (ACIA, 2004, 2005). Of particular note:

• Atmospheric climate patterns are shifting (Fig. 1). The late winter/spring pattern for 2000–2005 had new hot spots in northeast Canada and the East Siberian Sea relative to 1980–1999. Late ...


Preliminary Report On The Photo-Identification Of Blue Whales Off Isla De Chiloé, Chile From 2004 To 2006, Elsa Cabrera, Carole A. Carlson, Bárbara Galletti Vernazzani, Robert L. Brownell Jr. Jun 2006

Preliminary Report On The Photo-Identification Of Blue Whales Off Isla De Chiloé, Chile From 2004 To 2006, Elsa Cabrera, Carole A. Carlson, Bárbara Galletti Vernazzani, Robert L. Brownell Jr.

Publications, Agencies and Staff of the U.S. Department of Commerce

Photo identification of individual blue whales during summer and autumn off the northwestern Isla de Chiloé, southern Chile, were collected from marine surveys conducted from 2004 to 2006. Re-sightings of individual whales both within and between years may provide evidence of residency and site fidelity by blue whales in the area. These records further document the importance of the northwestern Isla de Chiloé as a feeding area for blue whales. These records also highlight the necessity of further comparisons with photographic catalogues from other areas in southern Chile, off the northwestern coast of South America and the Pacific coast of ...


Population Assessment Of Western Gray Whales In 2006, Justin G. Cooke, David W. Weller, Amanda L. Bradford, Alexander M. Burdin, Robert L. Brownell Jr. Jun 2006

Population Assessment Of Western Gray Whales In 2006, Justin G. Cooke, David W. Weller, Amanda L. Bradford, Alexander M. Burdin, Robert L. Brownell Jr.

Publications, Agencies and Staff of the U.S. Department of Commerce

A population assessment of the western gray whale (Eschrichtius robustus) was conducted using the Photo-identification data collected off Sakhalin Island under the joint Russia-U.S. program from 1994 to 2005. This is an update of the assessment by Reeves et al (2005) which used data up to 2003, fitted to the same, individually-based population model. New median estimates of key population parameters (with 90% Bayesian confidence intervals) are 0.986 (0.975 - 0.995) for the adult survival rate; 0.72 (0.60 - 0.83) for the survival rate from calf to yearling; 3.0% per annum (2.1% – 4 ...


Cetacean Abundance In Hawaiian Waters Estimated From A Summer/Fall Survey In 2002, Jay Barlow Jan 2006

Cetacean Abundance In Hawaiian Waters Estimated From A Summer/Fall Survey In 2002, Jay Barlow

Publications, Agencies and Staff of the U.S. Department of Commerce

Cetacean abundance is estimated for the U.S. Exclusive Economic Zone (EEZ) around the Hawaiian Islands based on a ship line-transect survey from August to November, 2002. Sighting detection functions are estimated from this and other NOAA research surveys from 1986 to 2002 using a new, multiple-covariate approach. Twenty-four species were seen on this survey, including two species (Fraser’s dolphin [Lagenodelphis hosei] and sei whale [Balaenoptera borealis]) that had not been previously documented to occur in Hawaiian waters. The most abundant large whales are sperm whales (Physeter macrocephalus) and Bryde’s whales (Balaenoptera edeni). The most abundant delphinids are ...


Evaluation Of The National Weather Service Operational Hydrologic Model And Forecasts For The American River Basin, Eylon Shamir, Theresa M. Carpenter, Peter Fickenscher, Konstantine P. Georgakakos Jan 2006

Evaluation Of The National Weather Service Operational Hydrologic Model And Forecasts For The American River Basin, Eylon Shamir, Theresa M. Carpenter, Peter Fickenscher, Konstantine P. Georgakakos

Publications, Agencies and Staff of the U.S. Department of Commerce

This paper evaluates the National Weather Service operational hydrologic model and operational flow forecasts for several subbasins of the American River. The evaluation includes: (1) the quality of the 6-h operational flow forecasts with up to 5 days lead time; (2) the hydrologic model ability to reproduce observed mean daily flows; and (3) the reliability of the ensemble streamflow predictions of the hydrologic model to reproduce extremes of the monthly volume of full natural flow to Folsom Lake. The results indicate that the model represents the observed flow record well for sites and/or flow ranges unaffected by upstream regulation ...


Effect Of Deposition Conditions On Mechanical Properties Of Low-Temperature Pecvd Silicon Nitride Films, H. Huang, K. J. Winchester, A. Suvorova, B. R. Lawn, Y. Liu, X. Z. Hu, J. M. Dell, L. Faraone Jan 2006

Effect Of Deposition Conditions On Mechanical Properties Of Low-Temperature Pecvd Silicon Nitride Films, H. Huang, K. J. Winchester, A. Suvorova, B. R. Lawn, Y. Liu, X. Z. Hu, J. M. Dell, L. Faraone

Publications, Agencies and Staff of the U.S. Department of Commerce

The effect of deposition conditions on characteristic mechanical properties – elastic modulus and hardness – of low-temperature PECVD silicon nitrides is investigated using nanoindentation. It is found that increase in substrate temperature, increase in plasma power and decrease in chamber gas pressure all result in increases in elastic modulus and hardness. Strong correlations between the mechanical properties and film density are demonstrated. The silicon nitride density in turn is shown to be related to the chemical composition of the films, particularly the silicon/nitrogen ratio.


Continued Disappearance Of The Benthic Amphipod Diporeia Spp. In Lake Michigan: Is There Evidence For Food Limitation?, Thomas F. Nalepa, David L. Fanslow, Andrew J. Foley Iii, Gregory A. Lang, Brian J. Eadie, Michael A. Quigley Jan 2006

Continued Disappearance Of The Benthic Amphipod Diporeia Spp. In Lake Michigan: Is There Evidence For Food Limitation?, Thomas F. Nalepa, David L. Fanslow, Andrew J. Foley Iii, Gregory A. Lang, Brian J. Eadie, Michael A. Quigley

Publications, Agencies and Staff of the U.S. Department of Commerce

Benthic surveys were conducted in the southern basin of Lake Michigan and throughout the lake to assess trends in benthic populations, emphasizing recent changes in densities of the benthic amphipod Diporeia spp. and dreissenid mussels. In the southern basin, Diporeia populations declined 89%, 91%, and 45% between 1993 and 2002 at sites <30, 31–50, and 51–90 m, respectively. Lakewide, the population declined 65% between 1994–1995 and 2000. Over the same time period, dreissenid densities, particularly Dreissena bugensis, increased. Intensive studies at 45 m sites in the southeastern region examined changes in lipid content, age structure, and benthic food inputs relative to the hypothesis that food limitation was a factor in Diporeia’s disappearance. As Diporeia densities declined to zero, length–weight remained unchanged ...


Lessons From Monitoring Trends In Abundance Of Marine Mammals, Barbara L. Taylor, Melissa Martinez, Tim Gerrodette, Jay Barlow, Yvana N. Hrovat Jan 2006

Lessons From Monitoring Trends In Abundance Of Marine Mammals, Barbara L. Taylor, Melissa Martinez, Tim Gerrodette, Jay Barlow, Yvana N. Hrovat

Publications, Agencies and Staff of the U.S. Department of Commerce

We assessed scientists’ ability to detect declines of marine mammal stocks based on recent levels of survey effort, when the actual decline is precipitous. We defined a precipitous decline as a 50% decrease in abundance in 15 yr, at which point a stock could be legally classified as “depleted” under the U.S. Marine Mammal Protection Act.We assessed stocks for three categories of cetaceans: large whales (n = 23, most of which are listed as endangered), beaked whales (n = 11, potentially vulnerable to anthropogenic noise), and small whales/dolphins/porpoises (n = 69, bycatch in fisheries and important abundant predators), for ...


Blue Whale (Balaenoptera Musculus) Sightings And Recordings South Of The Aleutian Islands, Shannon Rankin, Jay Barlow, Kathleen M. Stafford Jan 2006

Blue Whale (Balaenoptera Musculus) Sightings And Recordings South Of The Aleutian Islands, Shannon Rankin, Jay Barlow, Kathleen M. Stafford

Publications, Agencies and Staff of the U.S. Department of Commerce

Blue whales have been sighted throughout the North Pacific Ocean (Mizroch et al. 1984), and were harvested around the Pacific Rim from Mexico to Japan (Fig. 1). The International Whaling Commission (IWC) currently recognizes only one stock of blue whales in the North Pacific (Donovan 1991); however, there may be up to five (reviewed in Stafford 2003). While past shipboard and aerial surveys in the Aleutian Island chain found no blue whales (Rice and Wolman 1982, Stewart et al. 1987), their contemporary presence in this area has been well documented by acoustic monitoring (Watkins et al. 2000, Stafford et al ...


Scientific Reports Of Soviet Whaling Expeditions In The North Pacific, 1955-1978, Yulia V. Ivashchenko, Phillip J. Clapham, Robert L. Brownell Jr. Jan 2006

Scientific Reports Of Soviet Whaling Expeditions In The North Pacific, 1955-1978, Yulia V. Ivashchenko, Phillip J. Clapham, Robert L. Brownell Jr.

Publications, Agencies and Staff of the U.S. Department of Commerce

The translated and annotated materials in this volume constitute a collection of 18 formerly secret internal reports written by Soviet scientists working aboard whaling factory ships in the North Pacific. The reports cover the period from 1955 to 1978. During most of this time, the USSR was engaged in a massive campaign of illegal whaling worldwide; these illegal catches continued until introduction of the International Whaling Commission’s International Observer Scheme in 1972. The reports were copied from the archives of the Pacific Research and Fisheries Center (TINRO) in Vladivostok by Alfred A. Berzin, the former director of TINRO’s ...


Studies Of Beaked Whale Diving Behavior And Odontocete Stock Structure In Hawai‘I In March/April 2006, Robin W. Baird, Gregory S. Schorr, Daniel L. Webster, Daniel J. Mcsweeney, Sabre D. Mahaffy Jan 2006

Studies Of Beaked Whale Diving Behavior And Odontocete Stock Structure In Hawai‘I In March/April 2006, Robin W. Baird, Gregory S. Schorr, Daniel L. Webster, Daniel J. Mcsweeney, Sabre D. Mahaffy

Publications, Agencies and Staff of the U.S. Department of Commerce

Small-boat surveys were undertaken in March/April 2006 off the west side of the island of Hawai‘i for the purposes of obtaining dive data from Blainville’s (Mesoplodon densirostris) and Cuvier’s (Ziphius cavirostris) beaked whales, as well as collecting biopsy samples and photo-identification of these and other species of odontocetes for studies of stock structure and residency patterns. There were 157 sightings of 13 species of odontocetes in 4,264 km of effort, with 120 genetic samples from seven species and over 29,000 photographs from 13 species obtained. Photographic matching to existing catalogs is currently underway for ...


A Survey For Odontocete Cetaceans Off Kaua‘I And Ni‘Ihau, Hawai‘I, During October And November 2005: Evidence For Population Structure And Site Fidelity, Robin W. Baird, Gregory S. Schorr, Daniel L. Webster, Sabre D. Mahaffy, Anne B. Douglas, Antoinette M. Gorgone, Daniel J. Mcsweeney Jan 2006

A Survey For Odontocete Cetaceans Off Kaua‘I And Ni‘Ihau, Hawai‘I, During October And November 2005: Evidence For Population Structure And Site Fidelity, Robin W. Baird, Gregory S. Schorr, Daniel L. Webster, Sabre D. Mahaffy, Anne B. Douglas, Antoinette M. Gorgone, Daniel J. Mcsweeney

Publications, Agencies and Staff of the U.S. Department of Commerce

Considerable uncertainty exists regarding population structure and population sizes of most species of odontocetes in the Hawaiian Islands. A small-boat based survey for odontocetes was undertaken off the islands of Kaua‘i and Ni‘ihau in October and November 2005 to photoidentify individuals and collect genetic samples for examining stock structure. Field effort on 24 days covered 2,194 km of trackline. Survey coverage was from shallow coastal waters out to over 3,000 m depth, though almost half (47%) was in waters less than 500 m in depth. There were 56 sightings of five species of odontocetes: spinner dolphins ...


Differential Expression Of Immune Response Genes In Steller Sea Lions (Eumetopias Jubatus): An Indicator Of Ecosystem Health?, Lizabeth Bowen, Brian Aldridge, Kimberlee Beckmen, Tom Gelatt, Lorrie Rea, Kathy Burek, Ken Pitcher, Jeffrey L. Stott Jan 2006

Differential Expression Of Immune Response Genes In Steller Sea Lions (Eumetopias Jubatus): An Indicator Of Ecosystem Health?, Lizabeth Bowen, Brian Aldridge, Kimberlee Beckmen, Tom Gelatt, Lorrie Rea, Kathy Burek, Ken Pitcher, Jeffrey L. Stott

Publications, Agencies and Staff of the U.S. Department of Commerce

Characterization of the polygenic and polymorphic features of the Steller sea lion major histocompatibility complex (MHC) provides an ideal window for evaluating immunologic vigor of the population and identifying emergence of new genotypes that reflect ecosystem pressures. MHC genotyping can be used to measure the potential immunologic vigor of a population. However, since ecosystem-induced changes to MHC genotype can be slow to emerge, measurement of differential expression of these genes can potentially provide real-time evidence of immunologic perturbations. MHC DRB genes were cloned and sequenced using peripheral blood mononuclear leukocytes derived from 10 Steller sea lions from southeast Alaska, Prince ...


Relating Chronic Toxicity Responses To Population-Level Effects: A Comparison Of Population-Level Parameters For Three Salmon Species As A Function Of Low-Level Toxicity, Julann A. Spromberg, James P. Meador Jan 2006

Relating Chronic Toxicity Responses To Population-Level Effects: A Comparison Of Population-Level Parameters For Three Salmon Species As A Function Of Low-Level Toxicity, Julann A. Spromberg, James P. Meador

Publications, Agencies and Staff of the U.S. Department of Commerce

Standard laboratory toxicity tests assess the physiological responses of individual organisms to exposure to toxic substances under controlled conditions. Time and space restrictions often prevent the assessment of population-level responses to a toxic substance. Contaminants can affect various biological functions (e.g. growth, fecundity or behavior), which may alter different demographic traits, leading to population-level impacts. In this study,immune suppression, reproductive dysfunction and somatic growth impairment were examined using life history matrix models for coho salmon (Oncorhynchus kisutch), sockeye salmon (Oncorhynchus nerka) and chinook salmon (Oncorhynchus tshawytscha). Our intent was to gauge the relative magnitude of response to toxic ...


Spatial Statistical Models That Use Flow And Stream Distance, Jay M. Ver Hoef, Erin Peterson, David Theobald Jan 2006

Spatial Statistical Models That Use Flow And Stream Distance, Jay M. Ver Hoef, Erin Peterson, David Theobald

Publications, Agencies and Staff of the U.S. Department of Commerce

We develop spatial statistical models for stream networks that can estimate relationships between a response variable and other covariates, make predictions at unsampled locations, and predict an average or total for a stream or a stream segment. There have been very few attempts to develop valid spatial covariance models that incorporate flow, stream distance, or both. The application of typical spatial autocovariance functions based on Euclidean distance, such as the spherical covariance model, are not valid when using stream distance. In this paper we develop a large class of valid models that incorporate flow and stream distance by using spatial ...


Survival Estimates Of Western Gray Whales Eschrichtius Robustus Incorporating Individual Heterogeneity And Temporary Emigration, Amanda Bradford, Paul R. Wade, David Weller, Alexander M. Burdin, Yulia V. Ivashchenko, Grigory A. Tsidulko, Glenn R. Vanblaricom, Robert L. Brownell Jr. Jan 2006

Survival Estimates Of Western Gray Whales Eschrichtius Robustus Incorporating Individual Heterogeneity And Temporary Emigration, Amanda Bradford, Paul R. Wade, David Weller, Alexander M. Burdin, Yulia V. Ivashchenko, Grigory A. Tsidulko, Glenn R. Vanblaricom, Robert L. Brownell Jr.

Publications, Agencies and Staff of the U.S. Department of Commerce

Gray whales Eschrichtius robustus exist as a 2 geographically and genetically distinct populations in the eastern and western North Pacific. Subjected to intensive commercial whaling during the 19th and 20th centuries, the western population presently numbers approximately 100 individuals and is regarded as one of the most endangered baleen whale populations in the world.