Search results

Title: Pelodera strongyloides infection in Pacific Harbor seals (Phoca Vitulina Richardii) from California
Description: Marine Mammals, Birds & Turtles
Author: McHuron, Miller, Gardiner, Batac, Harvey
Date: 2013-01-01T00:00:00Z

Title: Lesions and behavior associated with forced copulation of juvenile Pacific harbor seals (Phoca vitulina richardsi) by southern sea otters (Enhydra lutris nereis),
Description: Nineteen occurrences of interspecific sexual behavior between male southern sea otters (Enhydra lutris nereis) and juvenile Pacific harbor seals (Phoca vitulina richardsi) were reported in Monterey Bay, California, between 2000 and 2002. At least three different male sea otters were observed harassing, dragging, guarding, and copulating with harbor seals for up to 7 d postmortem. Carcasses of 15 juvenile harbor seals were recovered, and seven were necropsied in detail by a veterinary pathologist. Necropsy findings from two female sea otters that were recovered dead from male sea otters exhibiting similar behavior are also presented to facilitate a comparison of lesions. The most frequent lesions included superficial skin lacerations; hemorrhage around the nose, eyes, flippers, and perineum; and traumatic corneal erosions or ulcers. The harbor seals sustained severe genital trauma, ranging from vaginal perforation to vagino-cervical transection, and colorectal perforations as a result of penile penetration. One harbor seal developed severe pneumoperitoneum subsequent to vaginal perforation, which was also observed in both female sea otters and has been reported as a postcoital lesion in humans. This study represents the first description of lesions resulting from forced copulation of harbor seals by sea otters and is also the first report of pneumoperitoneum secondary to forced copulation in a nonhuman animal. Possible explanations for this behavior are discussed in the context of sea otter biology and population demographics., Marine Mammals, Birds & Turtles, ,
Author: Harris, Oates, Staedler, Tinker, Jessup, Harvey, Miller
Date: 2010-01-01T00:00:00Z

Title: Assessing avian predation on juvenile salmonids using passive integrated transponder tag recoveries and mark-recapture methods,
Description: Many populations of coho salmon Oncorhynchus kisutch and steelhead O. mykiss are listed under the U.S. Endangered Species Act. Until recently, the role of avian predation in limiting recovery of coho salmon and steelhead in central California coastal watersheds has been overlooked. We used recoveries of passive integrated transponder (PIT) tags from Año Nuevo Island (ANI), a breeding site for several species of piscivorous seabirds, to estimate predation rates on juvenile salmonids and identify susceptible life stages and species responsible for predation. A total of 34,485 PIT tags were deployed in coho salmon and steelhead in six watersheds in San Mateo and Santa Cruz counties. Tags were deposited on ANI by predators after ingestion of tagged fish. Because tags were not removed from the island and were detected on multiple sampling occasions, we were able to use mark-recapture models to generate a corrected minimum predation estimate. We used POPAN, a variation of the Jolly-Seber model, to generate an estimate of gross population abundance, which accounted for tags deposited on the island but not detected during surveys. Detections of 196 tags from surveys conducted between autumn 2006 and spring 2009 were incorporated into the model, producing a gross population estimate of 242 tags (SE = 9.8). Addition of tags detected between autumn 2009 and 2010 to the abundance estimate from POPAN produced a new minimum estimate of 362 tags on ANI. Western gulls Larus occidentalis probably were the primary predator depositing tags on ANI. Minimum predation estimates ranged from 0.1% (Soquel Creek) to 4.6% (Waddell Creek) of outmigrating coho salmon and steelhead smolts. Predation was potentially greater given still unquantified deposition of tags off-colony and destruction of tags during digestive processes of predators. Finally, avian predators targeted estuary-reared fish, which contributed disproportionately to adult populations, further impacting imperiled salmon populations. © American Fisheries Society 2012., Marine Mammals, Birds & Turtles, CODEN: NAJMD, ,
Author: Frechette, Osterback, Hayes, Bond, Moore, Shaffer, Harvey
Date: 2012-01-01T00:00:00Z

Title: Domoic acid exposure and associated clinical signs and histopathology in Pacific harbor seals (Phoca vitulina richardii),
Description: Domoic acid (DA) is a potent neurotoxin that has caused strandings and mortality of seabirds and marine mammals off the California coast. Pacific harbor seals (Phoca vitulina richardii) are an abundant, nearshore species in California; however, DA exposure and toxicosis have not been documented for harbor seals in this region. To investigate DA exposure in harbor seals, samples were collected from free-ranging and stranded seals off California to assess exposure, clinical signs of toxicosis, and brain lesions in harbor seals exposed to DA. Domoic acid was detected in 65% (17/26) of urine samples collected from apparently healthy free-ranging seals, with concentrations of 0.4-11.7. ng/ml. Domoic acid also was detected in feces (2.4-2887. ng/g), stomach contents (1.4. ng/g; stranded only), milk (2.2. ng/ml; stranded only), amniotic fluid (9.7. ng/ml; free-ranging only), fetal meconium (14.6-39.8. ng/g), and fetal urine (2.0-10.2. ng/ml). Clinical signs indicative of DA toxicosis were observed in two live-stranded seals, and included disorientation, seizures, and uncoordinated movements. Histopathology revealed the presence of brain lesions consistent with DA toxicosis in two live-stranded seals, and one free-ranging seal that died during capture. Results indicated that harbor seals were exposed to DA, exhibited clinical signs and histological lesions associated with DA exposure, and that pups were exposed to DA in utero and during lactation via milk. Future investigation is required to determine the magnitude of impact that DA has on the health and mortality of harbor seals. © 2013 Elsevier B.V., Marine Mammals, Birds & Turtles, CODEN: HAALD, ,
Author: McHuron, Greig, Colegrove, Fleetwood, Spraker, Gulland, Harvey, Lefebvre, Frame
Date: 2013-01-01T00:00:00Z

Title: Hair sampling location in harbor seals (Phoca vitulina) affects selenium and mercury concentrations: Implications for study design of trace element determination in pinnipeds
Description: Hair is used to determine trace elements exposure and status of pinnipeds because it is an excretory route for many elements and can be collected non-lethally. Despite increased use, there have been few studies on how sampling designs and procedures (e.g., hair type, collection site) affect results. The objective of this study was to determine whether concentrations of an essential (selenium; Se) and non-essential element (mercury; Hg) differed between hair samples collected from two body locations on harbor seals (Phoca vitulina). Concentrations of Se and total Hg (THg) differed between mid-dorsal midline and neck samples, and although the absolute differences were relatively small (Δabsolute Se=0.69μgg-1, Δabsolute THg=2.86μgg-1), the relative differences were large (Δrelative Se=49%, Δrelative THg=17%). These differences highlight the need to standardize the collection site for trace element determination in pinnipeds., Marine Mammals, Birds & Turtles Harbor Seals
Author: McHuron, Harvey, Castellini, O'Hara
Date: 2012-01-01T00:00:00Z

Title: Chronic oiling of marine birds in California by natural petroleum seeps, shipwrecks, and other sources
Description: We assessed temporal and spatial patterns of chronic oiling of seabirds in California during 2005-2010, using data on: (1) live oiled birds reported to the Oiled Wildlife Care Network (OWCN) from throughout the state, and (2) dead oiled birds found during systematic monthly beached-bird surveys in central California. A mean of 245 (±141 SD) live miscellaneous oiled birds (not associated with known oil spills) were reported to the OWCN per year, and 0.1 oiled dead birds km-1 per month were found on beach surveys in central California. Chemical fingerprinting of oiled feathers from a subset of these birds (n = 101) indicated that 89% of samples tested were likely from natural petroleum seeps off southern and central California. There was a pronounced peak during late winter in the number of oiled birds reported in southern California, which we theorize may be related to large storm waves disturbing underwater seeps. © 2013., Marine Mammals, Birds & Turtles, Article in Press
Author: Henkel, Nevins, Martin, Sugarman, Harvey, Ziccardi
Date: 2014-01-01T00:00:00Z

Title: An application of underwater imaging for marine vertebrate ecology,
Description: Moss Landing Marine Laboratories (MLML) and the National Marine Fisheries Service have conducted leatherback (Dermochelys coriacea) sea turtle research for the last eight years. Leatherbacks come to the central California coast to forage on concentrations of jellyfish that accumulate in the nutrient rich waters over the coastal shelf. The research includes tracking leatherbacks across the Pacific Ocean with satellite transmitters, suction-cup attachment of time-depth-recorders (TDR) tags, and collection of morphological data. The TDRs are used to record the dive profiles of the leatherbacks foraging for jellyfish near shore. The TDR data provide graphical representation of the dive profile, showing decent and ascent rates, along with variations or deviations in the ascent pattern. This paper describes an application of a modest, but unique underwater imagining system designed and constructed at MLML to answer some of the questions inspired by the dive profiles. MLML's Turtle Cam synchronizes dive profiles with video images, providing researchers with a tool that is giving new insights to leatherback foraging ecology. ©2010 IEEE., Marine Mammals, Birds & Turtles, Art. No.: 5664044, ,
Author: Watson, Benson, Harvey
Date: 2010-01-01T00:00:00Z

Title: Southern Hemisphere humpback whales wintering off Central America: Insights from water temperature into the longest mammalian migration,
Description: We report on a wintering area off the Pacific coast of Central America for humpback whales (Megaptera novaeangliae) migrating from feeding areas off Antarctica. We document seven individuals, including a mother/calf pair, that made this migration (approx. 8300 km), the longest movement undertaken by any mammal. Whales were observed as far north as 11° N off Costa Rica, in an area also used by a boreal population during the opposite winter season, resulting in unique spatial overlap between Northern and Southern Hemisphere populations. The occurrence of such a northerly wintering area is coincident with the development of an equatorial tongue of cold water in the eastern South Pacific, a pattern that is repeated in the eastern South Atlantic. A survey of location and water temperature at the wintering areas worldwide indicates that they are found in warm waters (21.1-28.3°C), irrespective of latitude. We contend that while availability of suitable reproductive habitat in the wintering areas is important at the fine scale, water temperature influences whale distribution at the basin scale. Calf development in warm water may lead to larger adult size and increased reproductive success, a strategy that supports the energy conservation hypothesis as a reason for migration. © 2007 The Royal Society., Cited By (since 1996):53, Marine Mammals, Birds & Turtles, ,
Author: Rasmussen, Palacios, Calambokidis, Saborío, Dalla Rosa, Secchi, Steiger, Allen, Stone
Date: 2007-01-01T00:00:00Z

Title: The transmission of phocine herpesvirus-1 in rehabilitating and free-ranging Pacific harbor seals (Phoca vitulina) in California,
Description: Phocine herpesvirus-1 (PhHV-1) causes regular outbreaks of disease in neonatal harbor seals (Phoca vitulina) at rehabilitation centers in Europe and in the U.S. To investigate transmission of this virus samples were collected from harbor seal pups during exposure studies at a Californian rehabilitation center from 1999 to 2002 and from free-ranging harbor seals off central California during the same period. The exposure studies provided evidence that PhHV-1 can be transmitted horizontally between animals most likely through direct contact with oro-nasal secretions. However vertical transmission may also occur, as adult female harbor seals were found to be shedding the virus in vaginal and nasal secretions, and premature newborn pups had evidence of early infection. Results also indicated that PhHV-1 infections were common in both free-ranging (40%, 49/121) and rehabilitating (54%, 46/85) young harbor seals, during the spring and early summer. This timing, which correlated with pupping and weaning, suggested that the majority of animals were infected and infective with PhHV-1 between pupping and breeding. © 2004 Elsevier B.V. All rights reserved., Cited By (since 1996):9, Marine Mammals, Birds & Turtles, CODEN: VMICD, ,
Author: Goldstein, Mazet, Gulland, Rowles, Harvey, Allen, King, Aldridge, Stott
Date: 2004-01-01T00:00:00Z

Title: Entanglements of marine mammals and seabirds in central California and the north-west coast of the United States 2001-2005,
Description: Entanglement records for seabirds and marine mammals were investigated for the period 2001-2005. The entanglement records were extracted from databases maintained by seven organizations operating along the west coast of the United States of America. Their programmes included beach monitoring surveys, rescue and rehabilitation and regional pinniped censuses. Records of 454 entanglements were documented in live animals and in carcasses for 31 bird species and nine marine mammal species. The most frequently entangled species were Common Murres, Western Gulls and California sea lions. The entanglement materials identified were primarily fishing related. Entanglements were recorded every year suggesting that although the incidence level differs annually, entanglement is a persistent problem. It is recommended that each programme records details in standardized categories to determine entanglement material sources. Numbers of entanglements observed during these surveys are likely to be a conservative view of the actual entanglement rate taking place at sea. © 2009 Elsevier Ltd., Cited By (since 1996):9, Marine Mammals, Birds & Turtles, CODEN: MPNBA, ,
Author: Moore, Lyday, Roletto, Litle, Parrish, Nevins, Harvey, Mortenson, Greig, Piazza, Hermance, Lee, Adams, Allen, Kell
Date: 2009-01-01T00:00:00Z

Title: Antibodies to phocine herpesvirus-1 are common in North American harbor seals (Phoca Vitulina),
Description: Phocine herpesvirus-1 (PhHV-1) has been associated with morbidity and high mortality in neonatal harbor seals (Phoca vitulina) along the Pacific coast of California (USA) and in northern Europe. Seals dying with PhHV-1 associated disease in California primarily have histopathologic evidence of adrenal necrosis or adrenalitis with herpesviral inclusion bodies. Little is known about prevalence of exposure to PhHV-1, modes of disease transmission, and viral pathogenesis in free-ranging harbor seal populations. To evaluate the prevalence in North America, 866 serum samples collected between 1994 and 2002 from harbor seals captured or stranded on the Pacific and Atlantic coasts of North America were assayed by enzyme linked immunosorbent assay (ELISA) for evidence of PhHV-1 exposure. Samples from three harbor seal age classes (pre-weaned, weaned, and subadults/adults) were obtained from each of four regions to compare exposure among sex, age class, and region. We found increasing prevalence with age as 37.5% of pre-weaned pups, 87.6% of weaned pups, and 99.0% of subadults and adults were seropositive. When accounting for age, no associations between seropositivity and sex or location of harbor seals were detected. These data indicate that PhHV-1 is endemic in the harbor seal populations of North America. © Wildlife Disease Association 2003., Cited By (since 1996):7, Marine Mammals, Birds & Turtles, ,
Author: Goldstein, Gulland, Aldridge, Harvey, Rowles, Lambourn, Jeffries, Measures, Yochem, Stewart, Small, King, Stott, Mazet
Date: 2003-01-01T00:00:00Z

Title: Corrigendum to "Total mercury body burden in Pacific harbor seal, Phoca vitulina richardii, pups from central California"
Description: Marine Mammals, Birds & Turtles Harbor Seals, CODEN: MPNBA
Author: Brookens, O'Hara, Taylor, Bratton, Harvey
Date: 2009-01-01T00:00:00Z

Title: Abundance, seasonal distribution and population composition of balaenopterid whales in the Canal de Ballenas, Gulf of California, Mexico,
Description: Blue whales Balaenoptera musculus were most abundant in April and May while minke B. acutorostrata whales were equally abundant throughout the year. Fin B. physalus and Bryde's whales B. edeni were found but fin whales were more abundant in winter and spring; numbers were negatively correlated with water temperature. Bryde's whales were more abundant in summer and fall; numbers were positively correlated with water temperature. The percentage of identified individual adults that were females with calves was 10.6 for Bryde's and 2.7 for fin whales., Cited By (since 1996):13, , , Marine Mammals, Birds & Turtles
Author: Tershy, Breese, Strong
Date: 1990-01-01T00:00:00Z

Title: Stable carbon and nitrogen isotopes in multiple tissues of wild and captive harbor seals (Phoca vitulina) off the California coast
Description: Stable carbon and nitrogen isotope ratios (δ13C and δ15N) of serum, red blood cells (RBC), muscle, and blubber were measured in captive and wild northeast Pacific harbor seals (Phoca vitulina richardii) at three coastal California sites (San Francisco Bay, Tomales Bay, and Channel Islands). Trophic discrimination factors (ΔTissue-Diet) were calculated for captive seals and then applied in wild counterparts in each habitat to estimate trophic position and feeding behavior. Trophic discrimination factors for δ15N of serum (+3.8‰), lipid-extracted muscle (+1.6‰), and lipid-blubber (+6.5‰) are proposed to determine trophic position. An offset between RBC and serum of +0.3‰ for δ13C and -0.6‰ for δ15N was observed, which is consistent with previous research. Specifically, weaner seals (<1 yr) had large offsets, suggesting strong trophic position shifts during this life stage. Isotopic values indicated an average trophic position of 3.6 at both San Francisco Bay and Tomales Bay and 4.2 at Channel Islands. Isotopic means were strongly dependent on age class and also suggested that mean diet composition varies considerably between all locations. Together, these data indicate that isotopic composition of blood fractions can be an effective approach to estimate trophic position and dietary behavior in wild pinnipeds. © 2011 by the Society for Marine Mammalogy., Cited By (since 1996):1, Marine Mammals, Birds & Turtles, CODEN: MMSCE
Author: Germain, McCarthy, Koch, Harvey

Title: Age and sex of Common Murres Uria aalge recovered during the 1997-98 Point Reyes Tarball Incidents in central California,
Description: We examined 1,138 Common Murre Uria aalge carcasses recovered along the central California coast from November 1997 through March 1998 during the Point Reyes Tarball Incidents, a prolonged oiling event traced to the sunken vessel S. S. Jacob Luckenbach. We used head plumage, supraorbital ridge, and bursa of Fabricius, to classify age among carcasses as hatch-year (HY), or after-hatch year (AHY). We then separated AHY birds into two maturity categories based on gonad development: subadult and adult. The observed age class composition (14.6% HY, 37.6% subadult, and 47.8% adult) was not different from expected values generated with a stage-based matrix model that assumed a year-round resident population. The sex ratio for HY birds was equal (1.2:1 ), indicating little difference in at-sea distribution among male and female HY birds during winter. We found male-biased sex ratios in subadult (1.6:1) and adult (1.5:1) age classes. Sex-based differences in winter dispersal or colony attendance may have caused different risks to oiling among AHY birds. Mortality of mostly AHY murres during the Point Reyes Tarball Incidents and other oil spills has contributed to slow recovery of the central California population following historic and recent declines., Cited By (since 1996):11, Marine Mammals, Birds & Turtles, ,
Author: Nevins, Carter
Date: 2003-01-01T00:00:00Z

Title: Active acoustic examination of the diving behavior of murres foraging on patchy prey,
Description: During the 2008 and 2009 breeding seasons of murres Uria spp., we combined visual observations of these predators with active acoustics (sonar), fish trawls, zooplankton net tows, and hydrographic measurements in the area surrounding breeding colonies in the southeastern Bering Sea. We acoustically detected thousands of bubble trails that were strongly correlated with the number of visually detected murres, providing a new tool for quantitatively studying the foraging ecology of diving birds. At the regional scale, the number of acoustically detected bubble trails, which served as a proxy for diving murre abundance, was related to the combined availability and vertical accessibility of squid, krill, and pollock. There were, however, no clear relationships at this scale between diving murres and any individual prey taxon, highlighting the importance of prey diversity to these animals. Individual krill patches targeted by murres had higher krill density and were located shallower than the mean depth of krill patches, but were similar in total krill abundance and overall size. The diving depth of murres within krill patches was highly correlated to the depth of the upper edge of these patches, whereas murres found outside of krill patches showed a depth distribution similar to that of juvenile pollock. Throughout the study area, murres showed strong diel patterns in their diving behavior in response to the diel migrations of their prey. These results suggest that murres select prey with specific patch characteristics implying effective information gathering about prey by murres. The high proportion of diving murres in aggregations and their consistent inter-individual spacing support the hypothesis that intraspecific local enhancement may facilitate foraging in these predators. © 2011 Inter-Research., Cited By (since 1996):15, CODEN: MESED, , , Marine Mammals, Birds & Turtles
Author: Benoit-Bird, Kuletz, Heppell, Jones, Hoover
Date: 2011-01-01T00:00:00Z

Title: Effect of water clarity on the distribution of marine birds in nearshore waters of Monterey Bay, California,
Description: The distribution of marine birds relative to water clarity was examined in the nearshore waters of Monterey Bay, California. I conducted nine at-sea surveys in 1999 and 2000 and simultaneously recorded water clarity and the density of five taxa of marine birds. Among plunge-divers, Forster's Terns (Sterna forsteri) occurred more frequently than expected over turbid water (<2.5 m Secchi depth) and, among pursuit-diving species, Brandt's Cormorants (Phalacrocorax penicillatus) occurred most often in the clearest water available (>5 m Secchi depth). Turbidity in Monterey Bay may be caused by suspended organic matter, including phytoplankton, during summer and fall. Forster's Tern may prefer such areas because small fish are likely to occur near this potential food source. Brandt's Cormorants probably rely on vision to catch fish near the bottom and turbid water may reduce available light and limit visual acuity. The distribution of Brown Pelicans (Pelecanus occidentalis), Western/Clark's Grebes (Aechmophorus occidentalis/clarkii), and Marbled Murrelets (Brachyramphus marmoratus) did not appear to be influenced by turbidity levels, indicating that some seabirds use marine habitats with a wide range of water clarities. ©2006 Association of Field Ornithologists., Cited By (since 1996):8, Marine Mammals, Birds & Turtles, ,
Author: Henkel
Date: 2006-01-01T00:00:00Z

Title: Evaluating the function of the male harbour seal, Phoca vitulina, roar through playback experiments,
Description: The aim of this study was to evaluate the role of vocalizations produced during the breeding season by the male harbour seal, an aquatically breeding pinniped. During the spring of 1999, playback experiments were conducted at eight locations in Elkhorn Slough, California, U.S.A. Through an underwater speaker, we presented male harbour seals with three acoustic stimuli: a long-duration, low-frequency roar (LL), a short-duration, high-frequency roar (SH) and amplified water noise (control). Male responses to the playback boat were characterized by increased approach rates and aggressive flipper slapping during 62.5% of SH sessions (N=8), 25% of LL sessions (N=8) and 0% of control sessions (N=8). No more than one identifiable seal responded during each playback location. We observed no responses by female harbour seals to playbacks. We conclude from these experiments that territorial male harbour seals use roars given by intruders to locate and challenge intruders. © 2004 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved., Cited By (since 1996):11, Marine Mammals, Birds & Turtles, CODEN: ANBEA, ,
Author: Hayes, Kumar, Costa, Mellinger, Harvey, Southall, Le Boeuf
Date: 2004-01-01T00:00:00Z

Title: Effects of radiotransmitters on the reproductive performance of Cassin's auklets,
Description: We examined whether radiotransmitters adversely affected the reproductive performance of Cassin's auklets (Ptychoramphus aleuticus) breeding on the California Channel Islands during 1999-2001. We attached external radiotransmitters to 1 partner in 108 Cassin's auklet pairs after nest initiation and used 131 unmarked, but handled, pairs as controls. Compared to alpha chicks raised by radiomarked pairs, alpha chicks raised by unmarked pairs had faster mass growth rates (1.95 ± 0.30 g d -1 vs. 3.37 ± 0.53 g d -1, respectively), faster wing growth rates (2.46 ± 0.10 mm d -1 vs. 2.85 ± 0.05 mm d -1), greater peak fledging masses (118.9 ± 3.5 g vs. 148.3 ± 2.4 g), and higher fledging success (61% vs. 90%). Fledging success was reduced more when we radiomarked the male (50% fledged) rather than the female partner (77% fledged). After fledging an alpha chick, unmarked pairs were more likely to initiate a second clutch (radiomarked: 7%; unmarked: 39%) but did not hatch a second egg (radiomarked: 4%; unmarked: 25%) or fledge a second (beta) chick (radiomarked: 4%; unmarked: 18%) significantly more often than radiomarked pairs. We resighted 12 radiomarked individuals nesting during a subsequent breeding season; each bird had shed its transmitter and healed the site of attachment. We suggest caution in using telemetry to evaluate the reproductive performance of alcids, but marking only females may minimize adverse effects., Cited By (since 1996):25, Marine Mammals, Birds & Turtles, CODEN: WLSBA, ,
Author: Ackerman, Adams, Takekawa, Carter, Whitworth, Newman, Golightly, Orthmeyer
Date: 2004-01-01T00:00:00Z

Title: Estimates of humpback whale abundance off Kauai, 1989 to 1993: Evaluating biases associated with sampling the Hawaiian Islands breeding assemblage,
Description: Identification photographs of humpback whales Megaptera novaeangliae, collected off Kauai during the years 1989 to 1993, were used to estimate population abundance off the Hawaiian Islands, USA. A total of 790 different individuals (988 different observations) were identified during the study. Several mark-recapture procedures were applied to the data using closed population models (Chapman's modified Petersen, weighted mean of the Petersen, Darroch's maximum likelihood estimator [MLE], and Chao's M(t), M(h), and M(th) estimators) and an open population model (Fisher-Ford estimator). The majority of population estimates were between 2000 and 5000 animals, with broad and overlapping 95% confidence intervals. Inconsistencies in pair-wise Petersen estimates and poor fit to the Fisher-Ford model indicated that the population of individuals was not identical for each sampling occasion. As a primary example of this, it is suggested that individuals captured in 1992 had a lower probability of capture in other years examined. Possibly the greatest problems in estimating abundance of this population dealt with temporary emigration and non-random mixing of the population between sampling occasions. After considering the range of estimates, and potential biases in the data set, I suggest that the abundance of humpback whales off the Hawaiian Islands is likely close to 4000 individuals, and most probably between 3000 and 5000. These estimates are considerably greater than those generated in the late 1970s and early 1980s and, if accurate, would indicate growth of the population over the past decade; however, it is strongly recommended that more representative and precise estimates be obtained for management purposes., Cited By (since 1996):21, Marine Mammals, Birds & Turtles, CODEN: MESED, ,
Author: Cerchio
Date: 1998-01-01T00:00:00Z

Title: Beach use, internesting movement, and migration of leatherback turtles, Dermochelys coriacea, nesting on the North Coast of Papua New Guinea,
Description: Internesting and migratory movements of female leatherback turtles (Dermochelys coriacea) from Kamiali Wildlife Management Area were tracked by satellite telemetry during the 2001-2002 and 2002-2003 nesting seasons, and an aerial survey of nearly 2800 km of the north Papua New Guinea coastline and New Britain Island was conducted during January 2004. Nesting occurred during November-March at the Kamiali Wildlife Management Area monitoring beach with peak activity during December-January. Telemetry results indicated that nesting females used Huon Gulf waters adjacent to the nesting beach and renested inside and outside the protected area within the Kamiali Wildlife Management Area. After nesting, the turtles migrated over deep waters in a southeastern direction to high latitude waters of the South Pacific Ocean. © 2007 Chelonian Research Foundation., Cited By (since 1996):18, Marine Mammals, Birds & Turtles, ,
Author: Benson, Kisokau, Ambio, Rei, Dutton, Parker
Date: 2007-01-01T00:00:00Z

Title: Contaminant loads and hematological correlates in the harbor seal (Phoca vitulina) of San Francisco Bay, California,
Description: An expanding body of research indicates that exposure to contaminants may impact marine mammal health, thus possibly contributing to population declines. The harbor seal population of the San Francisco Bay (SFB), California, has suffered habitat loss and degradation, including decades of environmental contamination. To explore the possibility of contaminant-induced health alterations in this population, blood levels of polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (DDE), and polybrominated diphenyl ethers (PBDEs) were quantified in free-ranging seals; relationships between contaminant exposure and several key hematological parameters were examined; and PCB levels in the present study were compared with levels determined in SFB seals a decade earlier. PCB residues in harbor seal blood decreased during the past decade, but remained at levels great enough that adverse reproductive and immunological effects might be expected. Main results included a positive association between leukocyte counts and PBDEs, PCBs, and DDE in seals, and an inverse relationship between red blood cell count and PBDEs. Although not necessarily pathologic, these responses may serve as sentinel indications of contaminant-induced alterations in harbor seals of SFB, which, in individuals with relatively high contaminant burdens, might include increased rates of infection and anemia. Copyright© Taylor & Francis Inc., Cited By (since 1996):22 Marine Mammals, Birds & Turtles, CODEN: JTEHD, ,
Author: Neale, Gulland, Schmelzer, Harvey, Berg, Allen, Greig, Grigg, Tjeerdema
Date: 2005-01-01T00:00:00Z

Title: Maneuverability by the sea lion Zalophus californianus: Turning performance of an unstable body design,
Description: Maneuverability is critical to the performance of fast-swimming marine mammals that use rapid turns to catch prey. Overhead video recordings were analyzed for two sea lions (Zalophus californianus) turning in the horizontal plane. Unpowered turns were executed by body flexion in conjunction with use of the pectoral and pelvic flippers, which were used as control surfaces. A 90° bank angle was used in the turns to vertically orient the control surfaces. Turning radius was dependent on body mass and swimming velocity. Relative minimum radii were 9-17% of body length and were equivalent for pinnipeds and cetaceans. However, Zalophus had smaller turning radii at higher speeds than cetaceans. Rate of turn was inversely related to turn radius. The highest turn rate observed in Zalophus was 690 degrees s-1. Centripetal acceleration measured up to 5.1 g for Zalophus. Comparison with other marine mammals indicates that Zalophus has a morphology that enhances instability, thus providing enhanced turning performance. Enhanced turning performance is necessary for sea lions to forage after highly elusive prey in structurally complex environments., Cited By (since 1996):29, Marine Mammals, Birds & Turtles, CODEN: JEBIA, ,
Author: Fish, Hurley, Costa
Date: 2003-01-01T00:00:00Z

Title: Stable foraging areas and variable chick diet in Cassin's auklets (Ptychoramphus aleuticus) off southern California,
Description: Planktivorous seabirds readily respond to changes in marine ecosystems and have the ability to integrate information regarding variability in abundance, availability, and community composition of key prey resources. We studied the foraging and breeding ecology of the Cassin's auklet, Ptychoramphus aleuticus (Pallas, 1811), off southern California during three breeding seasons (1999-2001), when large intra- and inter-annual variability occurred in local oceanographic conditions during a prolonged La Nina event. Radio-marked parents used consistent core foraging areas within 30 km of their colony, aggregated in shelf waters (<200 m depth), and occasionally foraged in deeper waters. Parents delivered primarily euphausiids, pelagic larval-juvenile fishes, and minor amounts of cephalopods and other crustaceans. Whereas the euphausiid Thysanoessa spinifera Holmes, 1900 was most important during 1999 and 2001, Euphausia pacifica Hansen, 1911 replaced adult T. spinifera in 2000 after an anomalous eastward inflection of the California Current occurred near the auklets' foraging area. Differences in chick diets, however, did not significantly influence fledging success and growth among first chicks, but the proportion of pairs successfully fledging an alpha chick and initiating a second clutch was exceptional in 1999 (63%) and 2000 (75%), and less in 2001 (7%). We suggest that dietary composition was influenced by modified prey availability driven in part by fluctuations in regional upwelling and circulation. © 2004 NRC Canada., Cited By (since 1996):14, Marine Mammals, Birds & Turtles, CODEN: CJZOA, ,
Author: Adams, Takekawa, Carter
Date: 2004-01-01T00:00:00Z

Title: Dynamics of vibrio with virulence genes detected in Pacific harbor seals (Phoca vitulina richardii) off California: Implications for marine mammal health
Description: Given their coastal site fidelity and opportunistic foraging behavior, harbor seals (Phoca vitulina) may serve as sentinels for coastal ecosystem health. Seals using urbanized coastal habitat can acquire enteric bacteria, including Vibrio that may affect their health. To understand Vibrio dynamics in seals, demographic and environmental factors were tested for predicting potentially virulent Vibrio in free-ranging and stranded Pacific harbor seals (Phoca vitulina richardii) off California. Vibrio prevalence did not vary with season and was greater in free-ranging seals (29 %, n = 319) compared with stranded seals (17 %, n = 189). Of the factors tested, location, turbidity, and/or salinity best predicted Vibrio prevalence in free-ranging seals. The relationship of environmental factors with Vibrio prevalence differed by location and may be related to oceanographic or terrestrial contributions to water quality. Vibrio parahaemolyticus, Vibrio alginolyticus, and Vibrio cholerae were observed in seals, with V. cholerae found almost exclusively in stranded pups and yearlings. Additionally, virulence genes (trh and tdh) were detected in V. parahaemolyticus isolates. Vibrio cholerae isolates lacked targeted virulence genes, but were hemolytic. Three out of four stranded pups with V. parahaemolyticus (trh+ and/or tdh+) died in rehabilitation, but the role of Vibrio in causing mortality is unclear, and Vibrio expression of virulence genes should be investigated. Considering that humans share the environment and food resources with seals, potentially virulent Vibrio observed in seals also may be of concern to human health. © 2013 Springer Science+Business Media New York., Marine Mammals, Birds & Turtles Harbor Seals, CODEN: MCBEB
Author: Hughes, Greig, Miller, Byrne, Gulland, Harvey
Date: 2013-01-01T00:00:00Z

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