Search results

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: Pristiophorus lanae sp. nov., a new sawshark species from the western north Pacific, with comments on the genus Pristiophorus Müller & Henle, 1837 (Chondrichthyes: Pristiophoridae)
Description: A new species of sawshark, Pristiophorus lanae sp. nov., is described from off the Philippine Islands. The new species is the second member of the genus Pristiophorus described from the western North Pacific and can be separated from its closest geographic congener, P. japonicus, by having fewer rostral teeth in front of rostral barbels (17-26 versus 25-32), mouth at corners extending forward to below the rear margin of the eye versus extending below the rear one-third of eye margin, a greater mouth width at 6.9-7.8 times into pre-oral length (versus 5.8-6.9), eye length into head length (15.6-15.9 versus 9.8-13.2), mouth width into head length 9.0-10.0 versus 7.4-8.5 times, head width at nostrils 5.2-6.1 times into pre-orbital length versus 3.9-4.9 times, shorter prebarbel length (from snout tip to barbel) of 50.7-54.5% of preoral length versus 53.6-59.2%, a snout angle of 10.6-13.0° versus 12.4°-14.6°, and lateral trunk denticles with flat crowns that are imbricated versus erect crowns that are not imbricated. The number of monospondylous vertebrae is slightly lower in P. lanae (43-48) versus P. japonicus (51-52). The genus is reviewed, with a revised key to its species presented. © 2013 Magnolia Press., Cited By (since 1996):1, Export Date: 11 February 2014, Source: Scopus
Author: Ebert, Wilms
Date: 2013-01-01T00:00:00Z

Title: Effect of the bat star Asterina miniata (Brandt) on recruitment of the giant kelp Macrocystis pyrifera C. Agardh,
Description: Cited By (since 1996):10, Ecology, Seaweeds, CODEN: JEMBA, The effect of the common bat star, Asterina miniata (Brandt) on recruitment of the giant kelp, Macrocystis pyrifera C. Agardh, was addressed through laboratory grazing experiments, a field experiment, and modeling of feeding behavior. In the laboratory, Asterina miniata significantly decreased the density of sporophytes that developed from 1-wk-old gametophytes as well as the percent cover of 2-, 6-, and 7-wk-old sporophytes. All grazed blades remaining at the end of these experiments subsequently died. Small scale variability in spore settlement and sporophyte development were also evident in the laboratory. Bat star density significantly affected short-term kelp recruitment during a large-scale field experiment. Simple modeling suggested that high densities of Asterina miniata could graze nearly 100% of the bottom over the 90-day experiment. However, visible recruitment was seen in less than 30 days, and over this time, 36% of the substratum was predicted to have remained ungrazed. Macrocystis pyrifera of 1 to 3 cm in length may thus obtain a refuge in size from bat star grazing through rapid growth. These results indicate this generalist grazer can affect giant kelp recruitment but that even under high grazing pressure numerous plants survive. Bat star grazing probably does not contribute to large-scale differences in adult plant density but may contribute to small-scale patterns of dispersion., ,
Author: Leonard
Date: 1994-01-01T00:00:00Z

Title: Primary production, new production and vertical flux in the eastern Pacific Ocean,
Description: The sinking of participate organic matter in the ocean links food webs beneath the euphotic zone to surface primary production and is an important pathway for the downward transport of many elements 1-3. The flux of particulate organic carbon (POC) is also an important parameter in the global carbon cycle and may be related to long-term changes in atmospheric CO 24,5. In 1980, Suess 6synthesized existing measurements from sediment trap studies into a model to predict the vertical flux of POC from depth (z) and primary production (PP)6. The Suess model has become the standard for evaluating vertical flux data 7, for estimating the annual flux of POC in the ocean 8and for parameterizing ocean carbon cycle models 4,5. We present here a new model of the vertical flux of POC and particulate organic nitrogen (PON) from a set of contemporaneous measurements of PP and fluxes made during the VERTEX (Vertical Transport and Exchange) programme in the north-east Pacific. The VERTEX model indicates that PP and vertical fluxes of POC and PON, in the oligotrophic ocean are greater than previously suggested. In addition, the vertical flux of PON from the photic zone represents a measure of the PP that is supported by new nitrogen (new production) 9,10. In the north-east Pacific, new production ranged from 13 to 25% of primary production and was positively related to total PP. © 2002 Nature Publishing Group., Cited By (since 1996):144, ,
Author: Pace, Knauer, Karl, Martin
Date: 1987-01-01T00:00:00Z

Title: Marine mammal response to interannual variability in Monterey Bay, California
Description: The coastal upwelling ecosystem near Monterey Bay, California, is a productive yet variable ecosystem and an important foraging area for many mobile apex predators, such as marine mammals. Long-term studies are necessary to better understand how wide-ranging predators respond to temporal environmental variability; however, few of these studies exist. We conducted monthly shipboard line-transect surveys in Monterey Bay from 1997 to 2007. We identified 22 species of marine mammals, and calculated monthly and annual densities for the 12 most commonly sighted (focal) species. Species richness remained relatively constant (mean richness ± SE: 13.7 ± 0.396 species yr -1) from 1997 to 2006. Focal species were most evenly distributed (Shannon's equitability, E H = 0.820) but least dense (mean density ± SE: 0.0598 ± 0.0141) during the anomalous upwelling conditions of 2005, and least even (1997 E H = 0.413; 1998 E H = 0.407) but dense (mean density ± SE: 1997: 0.433 ± 0.177; 1998: 0.438 ± 0.169 ind. km -2) during the 1997/1998 El Niño event. There were no statistically significant differences in the densities of marine mammal species between warmer and cooler years. The community and species-specific responses of marine mammals to warm-water years differed depending on the mechanism of oceanographic variability. During the 1997/1998 El Niño (a basin-wide event), marine mammals aggregated in nearshore areas, such as Monterey Bay, with relatively greater productivity than offshore regions, whereas during anomalous upwelling conditions of 2005 (a more localized oceanographic event), marine mammals redistributed away from Monterey Bay to areas less affected by the anomaly. © Inter-Research 2012, Export Date: 24 September 2013
Author: Burrows, Harvey, Newton, Croll, Benson
Date: 2012-01-01T00:00:00Z

Title: Cobalt and copper distributions in the waters of Santa Monica Basin, California,
Description: The trace metals cobalt and copper are removed from the oceans interior by scavenging on to particle surfaces, but the mechanisms for removal of these two metals are probably quite different. Cobalt appears to be scavenged by manganese oxide particles, whereas organic compounds are the main carrier phase for copper. Remobilization of these metals in marine sediments therefore proceeds by different pathways. The differences in the pathways of remobilization are accentuated in oxygen-deficient environments: manganese oxide reduction is accelerated at low oxygen levels and organic carbon is preserved. Cobalt fluxes from sediments underlying oxygen-deficient waters should be enhanced and copper fluxes reduced. We report here measurements of the cobalt and copper distributions in the waters of an oxygen-deficient marine basin in the Southern California Bight. Cobalt concentrations near the bottom are raised four times above the background level, whereas copper concentrations show no increase. These measurements confirm features of existing models for the oceanic cycles of these metals., Cited By (since 1996):18, Oceanography, CODEN: NATUA, ,
Author: Johnson, Stout, Berelson, Sakamoto-Arnold
Date: 1988-01-01T00:00:00Z

Title: Temporal stability and origin of chemoclines in the deep hypersaline anoxic Urania basin
Description: Submarine brine lakes feature sharp and persistent concentration gradients between seawater and brine, though these should be smoothed out by free diffusion in open ocean settings. The anoxic Urania basin of the eastern Mediterranean contains an ultrasulfidic, hypersaline brine of Messinian origin above a thick layer of suspended sediments. With a dual modeling approach we reconstruct its contemporary stratification by geochemical solute transport fundamentals and show that thermal convection is required to maintain mixing in the brine and mud layer. The origin of the Urania basin stratification was dated to 1650 years B.P., which may be linked to a major earthquake in the region. The persistence of the chemoclines may be key to the development of diverse and specialized microbial communities. Ongoing thermal convection in the fluid mud layer may have important yet unresolved consequences for sedimentological and geochemical processes, also in similar environments. © 2015. American Geophysical Union. All Rights Reserved., Export Date: 19 February 2016, Article
Author: Goldhammer, Schwärzle, Aiello, Zabel
Date: 2015-01-01T00:00:00Z

Title: Chemical and biological interactions in the Rose Garden hydrothermal vent field, Galapagos spreading center,
Description: The concentrations of a suite of redox reactive chemicals were measured in the Rose Garden hydrothermal vent field of the Galapagos spreading center. Sulfide, silicate, oxygen and temperature distributions were measured in situ with a submersible chemical analyser. In addition, 15 chemical species were measured in discrete samples. Variability in the slope of the temperature-silicate plots indicates that heat is lost from these relatively low temperatures (<15°C) solutions by conduction to the solid phase. Consumption of oxygen, sulfide and nitrate from the hydrothermal solution as it flows past the vent animals is apparent from the distributions measured in situ and in the discrete samples. The fraction of sulfide and nitrate removed from the solution by consumption appears to have increased between 1979-1985. Sulfide and oxygen appear to be consumed under different conditions: sulfide is removed primarily from the warmest solutions, and oxygen is consumed only from the cold seawater. This separation may be driven primarily by the increased gradients of each chemical under these conditions. There is no evidence for the consumption of significant amounts of manganese(II) by the vent organisms. The analysis of other data sets from this vent field indicate no significant consumption of methane by the vent organisms, as well. © 1988., Cited By (since 1996):103, Oceanography, ,
Author: Johnson, Childress, Hessler, Sakamoto-Arnold, Beehler
Date: 1988-01-01T00:00:00Z

Title: Modeling the upper ocean dynamics in the Subantarctic and Polar Frontal Zones in the Australian sector of the Southern Ocean,
Description: A one-dimensional (1-D) mixed layer model (the Chen scheme) was applied in the Subantarctic Zone (SAZ) and the Polar Frontal Zone (PFZ) to simulate the upper ocean dynamics. The model was forced with 4 years data of the heat fluxes, freshwater fluxes, and wind stresses from the National Centers for Environmental Prediction. In both the SAZ and PFZ, the 1-D model was capable of reproducing the amplitude of the seasonal sea surface temperature (SST) and the seasonality of the mixed layer depth (MLD). The shallowest MLD was found in January-February (20 m in the SAZ, 35 m in the PFZ), and the deepest MLD was found between August and October (600 m in the SAZ, 160 m in the PFZ). The summer MLD was shallower in the SAZ than in the PFZ due to the lower wind stress. However, the shallower winter MLD in the PFZ than in the SAZ was due to the strong stratification in the water below the mixed layer. In the SAZ, variability in the wind stress was the dominant term driving the fluctuation in MLD in the summer, but variability in the heat flux was the major factor controlling the timing of the deepening and shoaling of the mixed layer in the winter. In the PFZ both the variability in the wind stress and the heat flux dominated the variability of the MLD in both the summer and the winter. Copyright 2001 by the American Geophysical Union., Cited By (since 1996):8, , , Downloaded from: http://onlinelibrary.wiley.com/doi/10.1029/2000JC000357/pdf (9 June 2014).
Author: Wang, Matear
Date: 2001-01-01T00:00:00Z

Title: Possible food caching and defence in the Weddell seal: Observations from McMurdo Sound, Antarctica,
Description: Cited By (since 1996):7, CODEN: ANTSE, , ,
Author: Kim, Conlan, Malone, Lewis
Date: 2005-01-01T00:00:00Z

Title: The vertical distribution and feeding habits of two common midwater fishes (Leuroglossus stilbius and Stenobrachius leucopsarus) off Santa Barbara,
Description: , Downloaded from: calcofi.org/publications/calcofireports/.../Vol_31_Cailliet___Ebeling.pdf (9 July 2014)., ,
Author: Cailliet, Ebeling
Date: 1990-01-01T00:00:00Z

Title: A shark antibody heavy chain encoded by a nonsomatically rearranged VDJ is preferentially expressed in early development and is convergent with mammalian IgG
Description: In most vertebrate embryos and neonates studied to date unique antigen receptors (antibodies and T cell receptors) are expressed that possess a limited immune repertoire. We have isolated a subclass of IgM, IgM1gj, from the nurse shark Ginglymostoma cirratum that is preferentially expressed in neonates. The variable (V) region gene encoding the heavy (H) chain underwent V-D-J rearrangement in germ cells "germline-joined"). Such H chain V genes were discovered over 10 years ago in sharks but until now were not shown to be expressed at appreciable levels; we find expression of H1gj in primary and secondary lymphoid tissues early in life, but in adults only in primary lymphoid tissue, which is identified in this work as the epigonal organ. H1gj chain associates covalently with light (L) chains and is most similar in sequence to IgM H chains, but like mammalian IgG has three rather than the four IgM constant domains; deletion of the ancestral IgM C2 domain thus defines both IgG and IgM1gj. Because sharks are the members of the oldest vertebrate class known to possess antibodies, unique or specialized antibodies expressed early in ontogeny in sharks and other vertebrates were likely present at the inception of the adaptive immune system., Cited By (since 1996):41, CODEN: PNASA, Fish and Fisheries
Author: Rumfelt, Avila, Diaz, Bartl, McKinney, Flajnik
Date: 2001-01-01T00:00:00Z

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: Dietary niche expansion of a kelp forest predator recovering from intense commercial exploitation
Description: Marine ecosystems are increasingly at risk from overexploitation and fisheries collapse. As managers implement recovery plans, shifts in species interactions may occur broadly with potential consequences for ecosystem structure and function. In kelp forests off San Nicolas Island, California, USA, we describe striking changes in size structure and life history traits (e.g., size at maturation and sex change) of a heavily fished, ecologically important predator, the California sheephead (Semicossyphus pulcher). These changes occurred in two phases: (1) after intense commercial fishery exploitation in the late 1990s and (2) following recovery in the late 2000s, nearly a decade after management intervention. Using gut contents and stable-isotope values of sheephead and their prey, we found evidence for a dietary niche expansion upon recovery of population size structure to include increased consumption of sea urchins and other mobile invertebrate grazers by larger sized fish. By examining historical diet data and a time series of benthic community composition, we conclude that changes in dietary niche breadth are more likely due to the recovery of size structure from fishing than major shifts in prey availability. Size-dependent predator-prey interactions may have ecosystem consequences and management measures that preserve or restore size structure, and therefore historical trophic roles of key predators, could be vital for maintaining kelp forest ecosystem health. © 2014 by the Ecological Society of America., Fish and Fisheries
Author: Hamilton, Newsome, Caselle

Title: Contamination of the deep-sea,
Description: Cited By (since 1996):17 Oceanography, CODEN: MPNBA, , ,
Author: Ballschmiter, Froescheis, Jarman, Caillet
Date: 1997-01-01T00:00:00Z

Title: Sedimentation in McMurdo Sound, Antarctica: A disturbance mechanism for benthic invertebrates,
Description: A slumping event that occurred on permanent transect lines from 12- to 30- m depth located at Arrival Heights, McMurdo Sound, Antarctica in 1993, provided an opportunity to examine the effects of sediment-mediated disturbance on the benthic invertebrate fauna. The disturbance had a particularly significant impact on the soft coral Alcyonium paessleri, which resulted in 84% colony mortality downslope from the slump site compared to an average annual mortality rate of 14% on control transects. In contrast, anchor ice at the same site accounted for removal of 5% of the population in 1992. Laboratory experiments with A. paessleri colonies under conditions of periodic sediment resuspension indicate that the soft corals are susceptible to this form of disturbance. Our observations suggest they are capable of shedding fine silt in the laboratory, which might ex-plain the presence of A. paessleri in soft-sediment sites around McMurdo Sound. However, scarring by larger gravel in laboratory assays was slow to heal and may account for much of the colony mortality we observed. Several invertebrate-barren rocky benthic regions in McMurdo Sound were suggestive of historical slumping events. Given the removal of the smaller grain size sediments from these areas - a typically slow process it appears these communities are slow to recover. The long-term effects of sedimentation on the benthic communities are unknown, but the impact on A. paessleri, one of the most common and fastest growing species, suggests this disturbance mechanism could lead to significant restructuring of these communities., Cited By (since 1996):13, Invertebrates, CODEN: POBID, ,
Author: Slattery, Bockus
Date: 1997-01-01T00:00:00Z

Title: Population biology of the intertidal kelp, Alaria marginata Postels and Ruprecht: A non-fugitive annual,
Description: Persistence of annual plant populations requires sufficient seeds and suitable habitat for development and growth each year. Competition with perennials may prevent within site persistence and result in "fugitive" annual populations. Comparisons have been made between the population biology of annual macroalgae and terrestrial plants, but demographic information necessary to make strong comparisons is lacking for most of these algae, and life history differences may make such comparisons questionable. We studied population dynamics of the kelp Alaria marginata to determine if it was an annual and, if so, how populations persisted. This kelp is the dominant macroalga on exposed mid to low rocky intertidal shores along the Big Sur coast of California. Experimental clearings at two sites were used to assess recruitment timing and survivorship. Sporophytes were collected monthly to determine growth and fecundity. Recruitment occurred in late winter to early spring, primarily on geniculate corallines and residual A. marginata holdfasts. Thinning was inversely related to density, and occurred during the February through July growing season as larger thalli rapidly increased in length (up to 1.4 m month-1) and formed a thick canopy. Sorus development was positively related to size, began as early as March, peaked in late August-October, and decreased as adults were removed by winter surf. Spore release was generally highest (108-109 spores individual-11 h-1) between October and January and associated with high water motion. Survivorship of sporophytes beyond one year was < 1%, showing the populations were annual. Field observations and experiments on effects of canopy clearing, season of clearing, and influence of substrate type on recruitment were done to assess how these annual populations persist. Massive spore production at the onset of fall storms, survival of microscopic stages for 3-4 months facilitated by microhabitat refuges, rapid growth, large size and rapid maturation of sporophytes contributed to persistence. Furthermore, the dense stands with thick canopies may suppress potential competitors via shading and abrasion. Rather than being a fugitive, this combination of growth and life history features enables A. marginata and perhaps other large, annual kelps to maintain perennial populations. © 2005 Elsevier B.V. All rights reserved., Cited By (since 1996):9, CODEN: JEMBA, ,
Author: McConnico, Foster
Date: 2005-01-01T00:00:00Z

Title: Particulate thallium fluxes in the northeast pacific,
Description: Particulate fluxes of thallium in the northeast Pacific exhibit pronounced spatial gradients, which range over four orders of magnitude (3 X 10-1 to 5.4 X 103 nmol m-2a-1) and show scavenging by both organic and inorganic processes. They are highly correlated (R=0.96) with POC fluxes, have have elevated rates in coastal upwelling waters, and decrease exponentially with depth. They also appear to be correlated with lateral fluxes of manganese (hydro)oxides off the continental shelf. These findings substantiate recent seawater measurements which indicate that metastable species of monovalent thallium are cycled through the marine biosphere as a potassium analogue, whereas thermodynamically stable trivalent thallium (TI (OH)3) is scavenged by ferromanganese (hydro)oxides. © 1989., Cited By (since 1996):11, CODEN: MRCHB, ,
Author: Flegal, Sanudo-Wilhelmy, Fitzwater
Date: 1989-01-01T00:00:00Z

Title: An overview on the role of Hexanchiformes in marine ecosystems,
Description: The large size, high trophic level and wide distribution of Hexanchiformes (cow and frilled sharks) should position this order as important apex predators in coastal and deep-water ecosystems. This review synthesizes available information on Hexanchiformes, including information not yet published, with the purpose of evaluating their conservation status and assessing their ecological roles in the dynamics of marine ecosystems. Comprising six species, this group has a wide global distribution, with members occurring from shallow coastal areas to depths of c. 2500 m. The limited information available on their reproductive biology suggests that they could be vulnerable to overexploitation (e.g. small litter sizes for most species and suspected long gestation periods). Most of the fishing pressure exerted on Hexanchiformes is in the form of commercial by-catch or recreational fishing. Comprehensive stock and impact assessments are unavailable for most species in most regions due to limited information on life history and catch and abundance time series. When hexanchiform species have been commercially harvested, however, they have been unable to sustain targeted fisheries for long periods. The potentially high vulnerability to intense fishing pressure warrants a conservative exploitation of this order until thorough quantitative assessments are conducted. At least some species have been shown to be significant apex predators in the systems they inhabit. Should Hexanchiformes be removed from coastal and deep-water systems, the lack of sympatric shark species that share the same resources suggests no other species would be capable of fulfilling their apex predator role in the short term. This has potential ecosystem consequences such as meso-predator release or trophic cascades. This review proposes some hypotheses on the ecology of Hexanchiformes and their role in ecosystem dynamics, highlighting the areas where critical information is required to stimulate research directions. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles., CODEN: JFIBA, , , Fish and Fisheries
Author: Barnett, Braccini, Awruch, Ebert
Date: 2012-01-01T00:00:00Z

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: Food habits of the two-line eelpout (Bothrocara brunneum: Zoarcidae) at two deep-sea sites in the eastern North Pacific,
Description: Two-line eelpouts were collected from two deep-sea sites in the eastern North Pacific in order to study food habits. The diet of this species is low in diversity, consisting primarily of shrimp-like crustaceans and secondarily of small zoarcid fishes. Although significant differences in diet exist between the two study sites, it appears that two-line eelpouts have a narrow dietary breadth. Previous and concurrent surveys of the region indicate that there is a wide range of potential prey available to two-line eelpouts; however, the species appears to be using a narrow range of benthopelagic fauna, suggesting that it is capable of some degree of prey specialization., Cited By (since 1996):7, CODEN: DRORE, ,
Author: Ferry
Date: 1997-01-01T00:00:00Z

Title: PCB and DDE contamination in harbor seals (Phoca vitulina) from North-Central California and Bristol Bay, Alaska,
Description: In recent years, concerns have increased regarding accumulation of persistent, lipophilic contaminants by marine mammals. We quantified blood levels of the two most prevalent organochlorine (OC) contaminants of the marine ecosystem in a model species, the harbor seal (Phoca vitulina) from three north-central California populations and a population in Bristol Bay, Alaska. Intensive sampling (n = 190) produced robust quantification of blood concentrations of selected PCBs and DDE, and allowed us to investigate factors affecting levels of these contaminants in seal populations with distinct environments and exposure histories. In the Alaskan samples, PCB and DDE levels were most strongly related to sex and age; OCs increased with age in males and decreased with age in females, likely due to cumulative exposure in males and load-dumping during lactation in females. Among females, an inverse relationship was observed between condition and PCB blood levels. In contrast, in the California seals, in which loads were generally much greater, pups had greater levels of PCBs and DDE than subadults and adults, suggesting stable to decreasing environmental contaminant levels. Spatial heterogeneity and seasonal differences also contributed substantially to variation among harbor seals in contaminant loads. These findings underscore the importance of accounting for demographic, geographic, seasonal, and physiological effects in toxicological studies of marine mammals., Cited By (since 1996):1, ,
Author: Neale, Schmelzer, Harvey, Berg, Small, Grigg, Allen, Tjeerderma
Date: 2009-01-01T00:00:00Z

Title: Development of a computer-aided age determination system,
Description: We have developed a computer-aided system (Bony Parts) to analyze periodic bands in fish otoliths (or other structures) for age estimation. The image analysis program first scans the image of a thin otolith section, perpendicular to the bands specified by the user. Adjacent scans are averaged and filtered with Fourier transformation or spatial domain convolution. Bands of higher density are detected and are marked and summed on the screen. We evaluated this new technique using subsamples of thin-sectioned otoliths from the bank rockfish Sebastes rufus. The time and effort for cleaning, preparation, sectioning, and mounting are the same for both traditional and computer-aided techniques. The computer-aided technique reduced the time and tedium of counting bands, yet still allowed the user to interactively make subjective decisions about aging criteria. Both approaches produced similar readings, but computer-aided estimates were more precise than traditional readings and required less analysis time. Thus, this new technique allows sample size and precision to be increased for a given amount of effort. Use of this new technique to age 1,897 sections produced von Bertalanffy growth equations that indicate female bank rockfish grow to a larger theoretical maximum size than males (L1 = 500.7 mm versus 438.1 mm total length) but grow at a slightly slower rate (K = 0.054 for females versus 0.073 for males., Cited By (since 1996):11, Fish and Fisheries, CODEN: TAFSA, ,
Author: Cailliet, Botsford, Brittnacher, Ford, Matsubayashi, King, Waiters, Kope
Date: 1996-01-01T00:00:00Z

Title: The relationship between water motion and living rhodolith beds in the southwestern Gulf of California, Mexico,
Description: Free living, nodular aggregates of non-geniculate coralline algae (rhodoliths) have occurred since the Cenozoic in diverse marine environments around the world. Fossil rhodolith morphology and distribution have been widely used as paleoecological indicators, particularly of water motion. However, few studies have verified these relationships in living beds. The relationship between water motion and rhodolith movement was examined in three subtidal rhodolith beds off the southwestern coast of the Gulf of California, one dominated by wave action and two dominated by tidal currents. Field experiments and simultaneous video and current measurements taken during winter 1996 showed that rhodoliths in the shallow margins (4.5 m depths) of wave-dominated beds moved frequently due to threshold-level velocities from wind-propagated waves. Rhodoliths did not move in the middle and at deep margins of the bed due to attenuation of wave energy. Historical wind records and waveforcasting analysis indicate that shallow rhodolith movement is frequent only in the winter. In deep tidally dominated beds, maximum yearly tidal currents were not sufficient to move rhodoliths. Video and SCUBA surveys showed that bioturbation is an important mechanism for rhodolith movement in all beds. Rhodoliths in 12-m-deep tidally dominated beds and in the deep margins of wave-dominated beds appear to move only occasionally due to bioturbation and severe storms. Results imply that rhodolith morphology and distribution are dependent on a combination of factors. These factors, especially bioturbation, should be considered when using rhodoliths as paleoecological indicators., Cited By (since 1996):66, ,
Author: Marrack
Date: 1999-01-01T00:00:00Z

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