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- Keyword
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- Alaska (2)
- Benthos (2)
- Food webs (2)
- Acetylcholinesterase; behavior; carbamate; feeding; growth; modeling; Oncorhynchus tshawytscha; organophosphate; pesticide; population; salmon (1)
- Balaenoptera musculus (1)
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- Blue whale (1)
- Callorhinus ursinus (1)
- Canada (1)
- Compartments (1)
- Condition (1)
- Diporeia spp. (1)
- Dreissena (1)
- Dreissena polymorpha (1)
- Feedback (1)
- Hierarchical systems theory (1)
- Invasive species (1)
- Lake Michigan (1)
- Lakes (1)
- Macroinvertebrate-fish interaction (1)
- Marine mammals (1)
- Movements (1)
- Networks (1)
- North Pacific (1)
- Northern fur seal (1)
- Photo-identification (1)
- Photographs (1)
- Phytoplankton dynamics (1)
- Population (1)
- Population structure (1)
- Populations (1)
Articles 1 - 30 of 43
Full-Text Articles in Physical Sciences and Mathematics
Review Of The Evidence Used In The Description Of Currently Recognized Cetacean Subspecies, William F. Perrin, James G. Mead, Robert L. Brownell Jr.
Review Of The Evidence Used In The Description Of Currently Recognized Cetacean Subspecies, William F. Perrin, James G. Mead, Robert L. Brownell Jr.
United States Department of Commerce: Staff Publications
We reviewed the subspecies listed by Rice (1998) and those described since (a total of 49, in 19 species), assessing them against the criteria recommended by the recent Workshop on Shortcomings of Cetacean Taxonomy in Relation to Needs of Conservation and Management (Reeves et al., 2004). The workshop suggested that the subspecies concept can be construed to cover two types of entities: a) lineages diverging but not quite far along the continuum of divergence (still having significant gene flow with another lineage or lineages) to be judged as species, and b) lineages that may well be species but for which …
Mammal-Eating Killer Whales And Their Prey—Trend Data For Pinnipeds And Sea Otters In The North Pacific Ocean Do Not Support The Sequential Megafaunal Collapse Hypothesis, P. R. Wade, J. M. Ver Hoef, D. P. Demaster
Mammal-Eating Killer Whales And Their Prey—Trend Data For Pinnipeds And Sea Otters In The North Pacific Ocean Do Not Support The Sequential Megafaunal Collapse Hypothesis, P. R. Wade, J. M. Ver Hoef, D. P. Demaster
United States Department of Commerce: Staff Publications
Springer et al. (2003) proposed a sequential megafauna collapse hypothesis to explain the decline of pinniped species and northern sea otters in the North Pacific. This hypothesis has been critiqued at length by DeMaster et al. (2006), Mizroch and Rice (2006), Trites et al. (2007), and Wade et al. (2007). At the core of the sequential megafauna collapse (SMC) hypothesis is the idea that predation by killer whales caused the sequential declines of four prey species (Springer et al. 2003) in the vicinity of the Aleutian Islands, Bering Sea, and Gulf of Alaska. Wade et al. (2007) plotted trends regionally …
Birth-Intervals And Sex Composition Of Western Gray Whales Summering Off Sakhalin Island, Russia, David W. Weller, Amanda L. Bradford, Aimée R. Lang, Robert L. Brownell Jr., Alexander M. Burdin
Birth-Intervals And Sex Composition Of Western Gray Whales Summering Off Sakhalin Island, Russia, David W. Weller, Amanda L. Bradford, Aimée R. Lang, Robert L. Brownell Jr., Alexander M. Burdin
United States Department of Commerce: Staff Publications
Determining the birth-interval at which reproductive females produce calves is an indispensable component of studies on the population biology of large whales. In theory, shorter birth-intervals will result in a faster rate of population increase. Therefore, estimating this reproductive parameter is particularly important for modeling exercises designed to project the potential growth of a given population and, in the case of endangered populations, their ability to recover from a depleted state (e.g. Cooke et al., 2008). While a number of inherent biases exist with respect to determination of birth-intervals for baleen whales (Barlow and Clapham, 1997), dedicated sampling efforts and …
Review Of Applied Spatial Data Analysis With R By R. S. Bivand, E. J. Pebesma, And V. Gomez-Rubio, Jay M. Ver Hoef
Review Of Applied Spatial Data Analysis With R By R. S. Bivand, E. J. Pebesma, And V. Gomez-Rubio, Jay M. Ver Hoef
United States Department of Commerce: Staff Publications
Most authors struggle to pick a title that adequately conveys all of the material covered in a book. When I first saw Applied Spatial Data Analysis with R, I expected a review of spatial statistical models and their applications in packages (libraries) from the CRAN site of R. The authors’ title is not misleading, but I was very pleasantly surprised by how deep the word “applied” is here. The first half of the book essentially covers how R handles spatial data. To some statisticians this may be boring. Do you want, or need, to know the difference between S3 and …
Status Of Western Gray Whales Off Northeastern Sakhalin Island, Russia, In 2008, Alexander M. Burdin, Grigory A. Tsidulko, Maxim Sidorenko, Amanda L. Bradford, David W. Weller, Robert L. Brownell Jr.
Status Of Western Gray Whales Off Northeastern Sakhalin Island, Russia, In 2008, Alexander M. Burdin, Grigory A. Tsidulko, Maxim Sidorenko, Amanda L. Bradford, David W. Weller, Robert L. Brownell Jr.
United States Department of Commerce: Staff Publications
A collaborative Russia-U.S. research program on western gray whales (Eschrichtius robustus) summering off northeastern Sakhalin Island, Russia, has been ongoing since 1995 and has produced important information on the present day conservation status of this critically endangered population. This paper reviews findings from 2008 research activities and combines such with data from previous years, in some cases ranging back to an opportunistic survey in 1994. Photo-identification research conducted off Sakhalin Island in 2008 resulted in the identification of 45 whales, including three calves. No previously unidentified non-calves were observed. When combined with data from 1994-2007, a catalog of …
Worldwide Review Of Pygmy Killer Whales, Feresa Attenuate, Mass Strandings Reveals Taiwan Hot Spot, Robert L. Brownell Jr., C.-J. Yao, Chia-Shan Lee, Ming-Chih Wang
Worldwide Review Of Pygmy Killer Whales, Feresa Attenuate, Mass Strandings Reveals Taiwan Hot Spot, Robert L. Brownell Jr., C.-J. Yao, Chia-Shan Lee, Ming-Chih Wang
United States Department of Commerce: Staff Publications
Pygmy killer whales, Feresa attentuata, are known worldwide from tropical to warm-temperate waters. The first recorded mass stranding event (MSE) of this species occurred in January 1968 in South Africa. We documented 16 MSEs to April 2006 in Bali, Indonesia. The number of animals involved in these MSEs ranged from 3 to 28, but most MSEs were less than eight animals. Taiwan was identified as a major hot spot for these MSEs with 25% of the events occurring since 1995 in a relatively small section of coastline in the south-west. Three additional near MSEs were documented from Taiwan between …
Alaska Marine Mammal Stock Assessments, 2008, R. P. Angliss, B. M. Allen
Alaska Marine Mammal Stock Assessments, 2008, R. P. Angliss, B. M. Allen
United States Department of Commerce: Staff Publications
This report provides information on the marine mammal stocks of Alaska under the jurisdiction of the National Marine Fisheries Service. Each stock assessment includes, when available, a description of the stock’s geographic range, a minimum population estimate, current population trends, current and maximum net productivity rates, optimum sustainable population levels and allowable removal levels, and estimates of annual human-caused mortality and serious injury through interactions with commercial fisheries and subsistence hunters. These data will be used to evaluate the progress of each fishery towards achieving the MMPA’s goal of zero fishery-related mortality and serious injury of marine mammals. The Stock …
A Trans-Holocene Archaeological Record Of Guadalupe Fur Seals (Arctocephalus Townsendi) On The California Coast, Torben Rick, Robert Delong, Jon Erlandson, Todd Braje, Terry Jones, Douglas Kennett, Thomas Wake, Phillip Walker
A Trans-Holocene Archaeological Record Of Guadalupe Fur Seals (Arctocephalus Townsendi) On The California Coast, Torben Rick, Robert Delong, Jon Erlandson, Todd Braje, Terry Jones, Douglas Kennett, Thomas Wake, Phillip Walker
United States Department of Commerce: Staff Publications
Guadalupe fur seals (Arctocephalus townsendi) were decimated by 19th century commercial sealers in the northeastern Pacific and thought to be extinct until 1928 when commercial fishermen caught two adult males at Isla de Guadalupe from a group of up to 60 adults and pups (Wedgeforth 1928, Huey 1930). These two animals were brought to the San Diego Zoo, prompting several zoological expeditions to Isla de Guadalupe in the 1930s and 1940s, but none successfully located Guadalupe fur seals. In 1949, a single male was seen on San Nicolas Island, California (Bartholomew 1950), and in 1954, a small breeding …
Record Of Feeding By Humpback Whales (Megaptera Novaeangliae) In Tropical Waters Off Brazil, Luiz Claudio Pinto De Sa Alves, Artur Andriolo, Alexandra Zerbini, Jose Luis Altmayer Pizzorno, Phillip Clapham
Record Of Feeding By Humpback Whales (Megaptera Novaeangliae) In Tropical Waters Off Brazil, Luiz Claudio Pinto De Sa Alves, Artur Andriolo, Alexandra Zerbini, Jose Luis Altmayer Pizzorno, Phillip Clapham
United States Department of Commerce: Staff Publications
Humpback whales (Megaptera novaeangliae) occur in all major oceans of the world, where most populations typically migrate between high-latitude summer feeding areas and low-latitude wintering grounds (Mackintosh 1942, Clapham and Mead 1999). Historical and contemporary data indicate that a humpback whale population spends the winter breeding season (typically June–November; Martins et al. 2001) in waters over the continental shelf off the eastern coast of South America (5°– 21°S; Williamson 1975, Zerbini et al. 2004, Andriolo et al. 2006). This population migrates through oceanic waters to summer subantarctic feeding destinations near South Georgia (∼54°S, 36°W) and the South Sandwich …
Movements And Dive Patterns Of A Rehabilitated Risso’S Dolphin, Grampus Griseus, In The Gulf Of Mexico And Atlantic Ocean, Randall Wells, Charles Manire, Lynne Byrd, David Smith, Janet Gannon, Deborah Fauquier, Keith Mullin
Movements And Dive Patterns Of A Rehabilitated Risso’S Dolphin, Grampus Griseus, In The Gulf Of Mexico And Atlantic Ocean, Randall Wells, Charles Manire, Lynne Byrd, David Smith, Janet Gannon, Deborah Fauquier, Keith Mullin
United States Department of Commerce: Staff Publications
Risso’s dolphins (Grampus griseus) occur throughout the world in tropical and temperate waters. The best estimates of abundance for Risso’s dolphins are 1,589 (CV = 0.27) for the northern Gulf of Mexico and 20,479 (CV = 0.59) for the U.S. Atlantic Ocean (Waring et al. 2006). G. griseus is the fourth most abundant cetacean species in the oceanic waters of the northern Gulf and is found in all seasons (Mullin et al. 1994, 2004; Maze-Foley and Mullin 2006).
Risso’s dolphins typically can be found over the continental shelf edge and the upper continental slope, where sea surface temperatures …
Northern Fur Seal Rookery Photo Archive: Aerial And Ground-Level Photos, Pribilof Islands, Alaska, 1895 - 2006, Kymberly M. Yano, Jessica Y. Tingg, Charles W. Fowler
Northern Fur Seal Rookery Photo Archive: Aerial And Ground-Level Photos, Pribilof Islands, Alaska, 1895 - 2006, Kymberly M. Yano, Jessica Y. Tingg, Charles W. Fowler
United States Department of Commerce: Staff Publications
The northern fur seal (Callorhinus ursinus) has been the subject of recorded history for more than two centuries (Scheffer et al. 1984, Scott et al. 2006). It has a long history of being commercially harvested for its valuable pelts (Roppel 1984). Recently, however, fur seals are being seen as one of many species reflecting the conditions of their environment, especially an environment increasingly altered by human influence. The Pribilof Islands fur seal population is currently listed as depleted under terms of the U.S. Marine Mammal Protection Act owing to numbers greatly reduced from those observed historically (National Marine …
Investigation Of Growth Phases For Bottlenose Dolphins Using A Bayesian Modeling Approach, Wayne Mcfee, John Schwacke, Megan Stolen, Keith Mullin, Lori Schwacke
Investigation Of Growth Phases For Bottlenose Dolphins Using A Bayesian Modeling Approach, Wayne Mcfee, John Schwacke, Megan Stolen, Keith Mullin, Lori Schwacke
United States Department of Commerce: Staff Publications
The Gompertz function is the most commonly used growth function for cetacean studies. However, this function cannot represent multiple phases of growth. In this study, we present a Bayesian framework fitting parameters of a triple-logistic growth function to describe multiple phases of growth for bottlenose dolphins (Tursiops truncatus), simultaneously fitting and comparing all growth parameters between South Carolina (SC), Mississippi Sound (MSS), and Indian River Lagoon (IRL) cohorts. The fitted functions indicated a preliminary early, rapid growth phase, followed by a second phase of slower growth, and then a moderate growth spurt later in life. Growth parameters between …
Population Structure Of Island-Associated Dolphins: Evidence From Photo-Identification Of Common Bottlenose Dolphins (Tursiops Truncates) In The Main Hawaiian Islands, Robin Baird, Antoinette Gorgone, Daniel Mcsweeney, Allan Ligon, Mark Deakos, Daniel Webster, Gregory Schorr, Karen Martien, Dan Salden, Sabre Mahaffy
Population Structure Of Island-Associated Dolphins: Evidence From Photo-Identification Of Common Bottlenose Dolphins (Tursiops Truncates) In The Main Hawaiian Islands, Robin Baird, Antoinette Gorgone, Daniel Mcsweeney, Allan Ligon, Mark Deakos, Daniel Webster, Gregory Schorr, Karen Martien, Dan Salden, Sabre Mahaffy
United States Department of Commerce: Staff Publications
Management agencies often use geopolitical boundaries as proxies for biological boundaries. In Hawaiian waters a single stock is recognized of common bottlenose dolphins, Tursiops truncatus, a species that is found both in open water and nearshore among the main Hawaiian Islands. To assess population structure, we photo-identified 336 distinctive individuals from the main Hawaiian Islands, from 2000 to 2006. Their generally shallow-water distribution, and numerous within-year and between-year resightings within island areas suggest that individuals are resident to the islands, rather than part of an offshore population moving through the area. Comparisons of identifications obtained from Kaua‘i/Ni‘ihau, O‘ahu, the …
Movements And Diving Behavior Of Pelagic Spotted Dolphins, Michael Scott, Susan Chivers
Movements And Diving Behavior Of Pelagic Spotted Dolphins, Michael Scott, Susan Chivers
United States Department of Commerce: Staff Publications
We radio tracked 20 pantropical spotted dolphins (Stenella attenuate) in the pelagic waters of the eastern tropical Pacific Ocean during three research cruises in 1992, 1993, and 2001. Dolphins were tracked for up to 6 d from 20 to 1,000 km offshore. Seventeen of these dolphins also carried time–depth recorders, nine of which were recovered with a combined total of 477 h of dive data. The movement data suggested that the dolphins associate with areas of relatively high biological productivity. Dolphins close to shore moved along the continental slope, while some dolphins traveled farther offshore along thermocline “ridges.” …
Behavior Of Melon-Headed Whales, Peponocephala Electra, Near Oceanic Islands, Robert L. Brownell Jr., Katherine Ralls, Simone Baumann-Pickering, M. Michael Poole
Behavior Of Melon-Headed Whales, Peponocephala Electra, Near Oceanic Islands, Robert L. Brownell Jr., Katherine Ralls, Simone Baumann-Pickering, M. Michael Poole
United States Department of Commerce: Staff Publications
Southall et al. (2006) concluded that a near mass stranding (MS) of melon-headed whales (MHWs), Peponocephala electra, in Hanalei Bay, Kauai, Hawaii, on 3–4 July 2004, was likely related to the operation of mid-frequency sonars (MFS). However, subsequent authors argued that the nearly simultaneous entry of MHWs into Sasanhaya Bay, Rota (∼5,740 km away) made this conclusion untenable. They suggested that both sightings, and other MSs of MHWs, could be related to lunar cycles. To resolve this question, we reviewed information on the biology and behavior of MHWs and compared the two sightings to observations of MHWs around Palmyra …
Adaptations In A Hierarchical Food Web Of Southeastern Lake Michigan, Ann E. Krause, Ken A. Frank, Michael L. Jones, Thomas F. Nalepa, Richard P. Barbiero, Charles P. Madenjian, Megan Agy, Marlene S. Evans, William W. Taylor, Doran M. Mason, Nancy J. Leonard
Adaptations In A Hierarchical Food Web Of Southeastern Lake Michigan, Ann E. Krause, Ken A. Frank, Michael L. Jones, Thomas F. Nalepa, Richard P. Barbiero, Charles P. Madenjian, Megan Agy, Marlene S. Evans, William W. Taylor, Doran M. Mason, Nancy J. Leonard
United States Department of Commerce: Staff Publications
Two issues in ecological network theory are: (1) how to construct an ecological network model and (2) how do entire networks (as opposed to individual species) adapt to changing conditions? We present a novel method for constructing an ecological network model for the food web of southeastern Lake Michigan (USA) and we identify changes in key system properties that are large relative to their uncertainty as this ecological network adapts fromone time point to a second time point in response to multiple perturbations. To construct our foodweb for southeastern Lake Michigan,we followed the list of seven recommendations outlined in Cohen …
Recent Changes In Benthic Macroinvertebrate Populations In Lake Huron And Impact On The Diet Of Lake Whitefish (Coregonus Clupeaformis), Thomas F. Nalepa, Steven A. Pothoven, David L. Fanslow
Recent Changes In Benthic Macroinvertebrate Populations In Lake Huron And Impact On The Diet Of Lake Whitefish (Coregonus Clupeaformis), Thomas F. Nalepa, Steven A. Pothoven, David L. Fanslow
United States Department of Commerce: Staff Publications
Surveys of the benthic macroinvertebrate community were conducted in the main basin of Lake Huron in 2000 and 2003, and corresponding studies of lake whitefish diets were conducted in 2002-2004. Populations of three major benthic taxa, Diporeia spp., Sphaeriidae, and Chironomidae, declined dramatically between 2000 and 2003, with densities declining 57%, 74%, and 75% over this 3-year period. By 2003, Diporeia, an important food source for lake whitefish, was gone or rare at depths <50 m except in the far northeastern portion of the lake. In contrast, densities of the Dreissena bugensis (quagga mussel) increased between 2000 and 2003, particularly at the 31-50 m depth interval, while densities of the zebra mussel Dreissena polymorpha remained stable. …
Draft U.S. Pacific Marine Mammal Stock Assessments: 2009, James V. Carretta, Karin A. Forney, Mark S. Lowry, Jay Barlow, Jason Baker, Dave Johnston, Brad Hanson, Robert L. Brownell Jr., Jooke Robbins, David K. Mattila, Katherine Ralls, Marcia M. Muto, Deanna Lynch, Lilian Carswell
Draft U.S. Pacific Marine Mammal Stock Assessments: 2009, James V. Carretta, Karin A. Forney, Mark S. Lowry, Jay Barlow, Jason Baker, Dave Johnston, Brad Hanson, Robert L. Brownell Jr., Jooke Robbins, David K. Mattila, Katherine Ralls, Marcia M. Muto, Deanna Lynch, Lilian Carswell
United States Department of Commerce: Staff Publications
Under the 1994 amendments to the Marine Mammal Protection Act (MMPA), the National Marine Fisheries Service (NMFS) and the U.S. Fish and Wildlife Service (USFWS) are required to publish Stock Assessment Reports for all stocks of marine mammals within U.S. waters, to review new information every year for strategic stocks and every three years for non-strategic stocks, and to update the stock assessment reports when significant new information becomes available. This report presents stock assessments for 13 Pacific marine mammal stocks under NMFS jurisdiction, including 8 “strategic” stocks and 5 “non-strategic” stocks (see summary table). A new stock assessment for …
Cetaceans Of Southeast Alaska: Distribution And Seasonal Occurrence, Marilyn E. Dahlheim, Janice M. Waite, Paula A. White
Cetaceans Of Southeast Alaska: Distribution And Seasonal Occurrence, Marilyn E. Dahlheim, Janice M. Waite, Paula A. White
United States Department of Commerce: Staff Publications
Aim To assess the distribution, group size, seasonal occurrence and annual trends of cetaceans.
Location The study area included all major inland waters of Southeast Alaska.
Methods Between 1991 and 2007, cetacean surveys were conducted by observers who kept a constant watch when the vessel was underway and recorded all cetaceans encountered. For each species, we examined distributional patterns, group size, seasonal occurrence and annual trends. Analysis of variance (anova F) was used to test for differences in group sizes between multiple means, and Student’s t-test was used to detect differences between pairwise means. Cetacean seasonal occurrence and annual trends …
Spatial Modelling And Prediction On River Networks: Up Model, Down Model Or Hybrid?, Vincent Garreta, Pascal Monestiez, Jay M. Ver Hoef
Spatial Modelling And Prediction On River Networks: Up Model, Down Model Or Hybrid?, Vincent Garreta, Pascal Monestiez, Jay M. Ver Hoef
United States Department of Commerce: Staff Publications
Preservation of rivers and water resources is crucial in most environmental policies and many efforts are made to assess water quality. Environmental monitoring of large river networks are based on measurement stations. Compared to the total length of river networks, their number is often limited and there is a need to extend environmental variables that are measured locally to the whole river network. The objective of this paper is to propose several relevant geostatistical models for river modeling. These models use river distance and are based on two contrasting assumptions about dependency along a river network. Inference using maximum likelihood, …
Demography And Population Viability Of Polar Bears In The Gulf Of Boothia, Nunavut, Mitchell Taylor, Jeff Laake, Philip Mcloughlin, H. Dean Cluff, Francois Messier
Demography And Population Viability Of Polar Bears In The Gulf Of Boothia, Nunavut, Mitchell Taylor, Jeff Laake, Philip Mcloughlin, H. Dean Cluff, Francois Messier
United States Department of Commerce: Staff Publications
We estimated demographic parameters and harvest risks for polar bears (Ursus maritimus) inhabiting the Gulf of Boothia, Nunavut, from 1976 to 2000. We computed survival and abundance from capture–recapture and recovery data (630 marks) using a Burnham joint live–dead model implemented in program MARK. Annual mean total survival (including harvest) was 0.889 ± 0.179 ( x ± 1 SE) for cubs, 0.883 ± 0.087 for subadults (ages 1–4), 0.919 ± 0.044 for adult females, and 0.917 ± 0.041 for adult males. Abundance in the last 3 yr of study was 1,592 ± 361 bears. Mean size of newborn …
Health Assessment Of Weddell Seals, Leptonychotes Weddellii, In Mcmurdo Sound, Antarctica, P.K. Yochem, B.S. Stewart, T.S. Gelatt, D.B. Siniff
Health Assessment Of Weddell Seals, Leptonychotes Weddellii, In Mcmurdo Sound, Antarctica, P.K. Yochem, B.S. Stewart, T.S. Gelatt, D.B. Siniff
United States Department of Commerce: Staff Publications
The demography of Weddell seals in eastern McMurdo Sound, Antarctica, has been well studied during the past three decades (e.g. Stirling 1971; Siniff et al. 1977; Testa and Siniff 1987; Hastings and Testa 1998; Gelatt et al. 2001). Detailed life-history data are available on thousands of seals tagged as pups in McMurdo Sound, making this population a rich resource for wildlife health studies because health parameters can be evaluated in the light of reproductive histories and genetic relationships of several generations of tagged seals.
Recently, evidence of exposure to diseases generally associated with domestic animals and feral wildlife has been …
A Fish Of Many Scales: Extrapolating Sublethal Pesticide Exposures To The Productivity Of Wild Salmon Populations, David H. Baldwin, Julann A. Spromberg, Tracy K. Collier, Nathaniel L. Scholz
A Fish Of Many Scales: Extrapolating Sublethal Pesticide Exposures To The Productivity Of Wild Salmon Populations, David H. Baldwin, Julann A. Spromberg, Tracy K. Collier, Nathaniel L. Scholz
United States Department of Commerce: Staff Publications
For more than a decade, numerous pesticides have been detected in river systems of the western United States that support anadromous species of Pacific salmon and steelhead. Over the same interval, several declining wild salmon populations have been listed as either threatened or endangered under the U.S. Endangered Species Act (ESA). Because pesticides occur in surface waters that provide critical habitat for ESA-listed stocks, they are an ongoing concern for salmon conservation and recovery throughout California and the Pacific Northwest. Because pesticide exposures are typically sublethal, a key question is whether toxicological effects at (or below) the scale of the …
Movements Of Satellite-Tagged Cuvier’S And Blainville’S Beaked Whales In Hawai‘I: Evidence For An Offshore Population Of Blainville’S Beaked Whales, Robin W. Baird, Gregory S. Schorr, Daniel L. Webster, Sabre D. Mahaffy, Daniel J. Mcsweeney, M. Bradley Hanson, Russel D. Andrews
Movements Of Satellite-Tagged Cuvier’S And Blainville’S Beaked Whales In Hawai‘I: Evidence For An Offshore Population Of Blainville’S Beaked Whales, Robin W. Baird, Gregory S. Schorr, Daniel L. Webster, Sabre D. Mahaffy, Daniel J. Mcsweeney, M. Bradley Hanson, Russel D. Andrews
United States Department of Commerce: Staff Publications
The impacts of mid-frequency active sonar on the behavior of individual cetaceans may vary depending on their history of prior exposure. Evidence from habitat use, repeated sightings of identified individuals, and satellite tagging all indicate the existence of resident populations of Cuvier’s and Blainville’s beaked whales off the island of Hawai‘i, within the Navy’s Hawai‘i Range Complex. The number of individuals that have been satellite tagged is small however, and we are combining additional satellite tagging with individual photo-identification studies to assess movements and residency of both species. Field efforts were undertaken off the island of Hawai‘i in December 2008 …
Anthropogenic Scarring Of Western Gray Whales (Eschrichtius Robustus), Amanda Bradford, David Weller, Yulia Ivaschenko, Alexander Burdin, Robert L. Brownell Jr.
Anthropogenic Scarring Of Western Gray Whales (Eschrichtius Robustus), Amanda Bradford, David Weller, Yulia Ivaschenko, Alexander Burdin, Robert L. Brownell Jr.
United States Department of Commerce: Staff Publications
Western gray whales (Eschrichtius robustus) are critically endangered and anthropogenic threats, such as entanglement in fishing gear and collisions with vessels, may be acting to limit recovery of the population. Thus, examining the magnitude of such anthropogenic interactions using a scar-based approach is warranted. A multi-year (1995–2005) photo-identification study of western gray whales on their feeding ground off northeastern Sakhalin Island, Russia, has resulted in a large data set of digital and film images of 150 individuals. These images were reviewed and scored for anthropogenic scarring by recording the presence of visible scars resulting from fishing gear entanglement …
Diet Of Pygmy Sperm Whales (Kogia Breviceps) In The Hawaiian Archipelago, Kristi West, William Walker, Robin Baird, Whitney White, Gregg Levine, Eric Brown, David Schofield
Diet Of Pygmy Sperm Whales (Kogia Breviceps) In The Hawaiian Archipelago, Kristi West, William Walker, Robin Baird, Whitney White, Gregg Levine, Eric Brown, David Schofield
United States Department of Commerce: Staff Publications
The biology and ecology of the pygmy sperm whale (Kogia breviceps) is poorly understood among odontocetes (McAlpine 2002). In Hawaiian waters, pygmy sperm whales are the second most frequently recorded stranded cetacean species, with 35 strandings documented between 1963 and 2008 (Shallenberger 1981, Nitta 1987, Maldini et al. 2005, NMFS database). Despite the high frequency of strandings, sightings of this species in Hawaiian waters are rare (Baird 2005). Given the low number of sightings, examination of stranded animals provides virtually the only means to study the biology and ecology of pygmy sperm whales in the area.
Do Monk Seals Exert Top-Down Pressure In Subphotic Ecosystems?, Frank Parrish
Do Monk Seals Exert Top-Down Pressure In Subphotic Ecosystems?, Frank Parrish
United States Department of Commerce: Staff Publications
Patterns of subphotic fish assemblages on seamounts in the Northwestern Hawaiian Islands were identified and compared for potential structuring influences, including the bottom-up effects of regional oceanic productivity and top-down predation pressure exerted by visiting monk seals (Monachus schauinslandi). Patterns in fish size, density, and biomass were evaluated at the deep extreme (350–500 m) of the seals feeding range to avoid confounding effects of diverse shallow habitats (e.g., coral reefs). Fish number and size were used to calculate biomass density of the seamount fish assemblages that were then compared to the independent variables of summit depth, substrate type, …
Blubber Testosterone: A Potential Marker Of Male Reproductive Status In Short-Beaked Common Dolphins, Nicholas Kellar, Marisa Trego, Corina Marks, Susan Chivers, Kerri Danil, Frederick Archer
Blubber Testosterone: A Potential Marker Of Male Reproductive Status In Short-Beaked Common Dolphins, Nicholas Kellar, Marisa Trego, Corina Marks, Susan Chivers, Kerri Danil, Frederick Archer
United States Department of Commerce: Staff Publications
A novel molecular technique was used to measure blubber testosterone (BT) in 114 male short-beaked common dolphins, Delphinus delphis, collected from incidental fishery bycatch and strandings. When these concentrations were compared across maturity states, the mean (± SEM) BT levels of mature D. delphis (14.3 ± 3.0 ng/g) were significantly higher than those of pubertal (2.5 ± 0.5 ng/g, P = 0.006) and immature animals (2.2 ± 0.3 ng/g, P < 0.0001). BT concentrations in mature males were significantly higher in summer months (53.9 ± 2.0 ng/g) than during the rest of the year (7.9 ± 0.69 ng/g, P < 0.0001), indicating reproductive seasonality. An analysis of BT in different anatomical locations showed that hormone concentrations were not homogenous throughout the body; the levels in the dorsal fin were significantly lower than in most other areas (F = 5.39, P = 0.043). Conversely, we found no significant differences in BT concentration with respect to subepidermal depth (F = 2.09, P = 0.146). Finally, testosterone levels in biopsies from 138 free-swimming male D. delphis, of unknown maturity state, sampled off California were found to be of concentrations similar to those from the fishery bycatch and stranding samples and revealed an …
Harvesting Young-Of-The-Year From Large Mammal Populations: An Application Of Systemic Management, C. W. Fowler, T. E. Jewell, M.V. Lee
Harvesting Young-Of-The-Year From Large Mammal Populations: An Application Of Systemic Management, C. W. Fowler, T. E. Jewell, M.V. Lee
United States Department of Commerce: Staff Publications
We evaluate the current commercial harvest of harp seal (Pagophilus groenlandicus) and proposed subsistence harvests of northern fur seal (Callorhinus ursinus ) pups based on intra-specific comparisons. These comparisons utilize a pattern derived from 167 cases of estimated consumption rates by large mammals. In all cases, the predation rates involve large mammal prey less than 1 year of age. Recent harvests of harp seal pups are exceeded by 20 (about 12%) of the estimated consumption rates among the nonhuman species. Although this is not statistically significant, further analysis may find this harvest to be unsustainable when we …
Treatment Of Northern Fur Seal (Callorhinus Ursinus) Pups With Ivermectin Reduces Hookworm-Induced Mortality, Robert Delong, Anthony Orr, Ryan Jenkinson, Eugene T. Lyons
Treatment Of Northern Fur Seal (Callorhinus Ursinus) Pups With Ivermectin Reduces Hookworm-Induced Mortality, Robert Delong, Anthony Orr, Ryan Jenkinson, Eugene T. Lyons
United States Department of Commerce: Staff Publications
A breeding population of approximately 8,000–10,000 northern fur seals (Callorhinus ursinus) is located at San Miguel Island in the California Channel Islands. The population is increasing and produces about 2,500 pups annually (Melin et al. 2008). Pup mortality has increased during the past 10 yr and has reached 50% or more in some recent years. Although we have not completed studies to describe the causes of this pup mortality, it appears that hookworm disease has been a major cause (Lyons et al. 2001).