Search results
(1 - 25 of 1,045)
Pages
- 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
- Mouth size and predator strategy of midwater fishes,
- Description
- It has been suggested that bathypelagic fishes should be equipped to eat any large or small food item that they should chance to meet in their relatively impoverished environment. The derived hypothesis that bathypelagic species are trophically generalized was indirectly substantiated in two taxonomic groups of midwater fishes. Bathypelagic members tend to be larger and have larger mouths than their mesopelagic relatives, but still have a well-developed pharyngeal basket for retaining small items. Bathypelagic offshoots of the primarily mesopelagic group of lanternfishes seem to have acquired larger mouths at the presumed metabolic expense of having proportionately larger bodies. The deeper-living members of the primarily lower mesopelagic or bathypelagic family Melamphaidae are further specialized in that they have disproportionately larger mouths with minimum additional body size. This discussed relative to theoretical considerations of foraging strategy and metabolic economy. © 1974., Cited By (since 1996):8, ,
- Author
- Ebeling, Cailliet
- Date
- 1974-01-01T00:00:00Z
- Title
- A new species of chimaera, Hydrolagus melanophasma sp. nov. (Chondrichthyes: Chimaeriformes: Chimaeridae), from the eastern North Pacific.,
- Description
- A new species of chimaera, Hydrolagus melanophasma sp. nov. (Chimaeridae), is described from the eastern North Pacific. It is distinct from other eastern Pacific chimaeroids by the following characteristics: a large slightly curved dorsal fin spine extending beyond dorsal fin apex, a long second dorsal fin of uniform height throughout, large pectoral fins extending beyond the pelvic fin insertion when laid flat, trifid claspers forked for approximately one-quarter the total clasper length and a uniform black coloration throughout. The new species is compared to other eastern Pacific members of the genus Hydrolagus including H. alphus, H. colliei, H. macrophthalmus, and H. mccoskeri. Remote Operated Vehicle (ROV) video footage has identified and documented Hydrolagus melanophasma from the Gulf of California. ROV observations suggest that individuals typically occur over soft-bottom habitats or cobble patches with minimal vertical relief. This is in contrast to other eastern Pacific Hydrolagus species that tend to occur in areas of high rocky relief. The known distribution of this new species at present extends from southern California, U.S.A., along the Pacific coast of Baja California, Mexico, and into the Gulf of California. © 2009 Magnolia Press., Cited By (since 1996):6, , , Fish and Fisheries
- Author
- James, Ebert, Long, Didier
- Date
- 2009-01-01T00:00:00Z
- Title
- The level of agreement among experts applying best professional judgment to assess the condition of benthic infaunal communities,
- Description
- Benthic infaunal communities are frequently used to assess aquatic environmental condition, but interpretation of benthic data is often subjective and based on best professional judgment. Here, we examine the repeatability of such assessments by providing species-abundance data from 35 sites to 9 independent benthic experts who ranked the sites from best to worst condition. Their site rankings were highly correlated, with an average correlation coefficient of 0.91. The experts also evaluated the sites in terms of four condition categories: (1) unaffected, (2) marginal deviation from reference, (3) affected, or (4) severely affected. At least two-thirds of the experts agreed on site categorization for 94% of the samples and they disagreed by more than one category for less than 1% of the assessment pairs. The experts identified seven parameters used in making their assessments, with four of those parameters (dominance by tolerant taxa, presence of sensitive taxa, species richness, and total abundance) used by all of the experts. Most of the disagreements in site categorization were due to philosophical rather than technical differences, such as whether the presence of invasive species indicates a degraded community. Indices are increasingly being used as an alternative to best professional judgment for assessing benthic condition, but there have been inconsistencies in how sites are selected for validating such indices; the level of agreement found among experts in this study suggests that consensus expert opinion can be a viable benchmark for such evaluations. © 2007 Elsevier Ltd. All rights reserved., Cited By (since 1996):29, Invertebrates, ,
- Author
- Weisberg, Thompson, Ranasinghe, Montagne, Cadien, Dauer, Diener, Oliver, Reish, Velarde, Word
- Date
- 2008-01-01T00:00:00Z
- Title
- Introduction to the systematics and biodiversity of sharks, rays, and chimaeras (Chondrichthyes) of Taiwan
- Description
- All 13 orders of chondrichthyan fishes occur in Taiwanese waters, representing 52 chondrichthyan families (31 shark, 19 batoid, 2 chimaeroid) and 98 genera (64 shark, 31 batoid, 3 chimaeroid). A total of 119 shark, 58 batoid, and 4 chimaera species may occur in the waters surrounding Taiwan, pending taxonomic resolution of some groups. Of the 34 nominally described species from Taiwan, 17 are currently considered valid. The majority of named species occurred during two peak periods in Taiwanese chondrichthyan research; the first between 1959-63, when 13 nominal species were described, of which 7 remain valid today, and a second peak period between 2003-13 when 9 nominal species were described, of which 6 remain valid. The overall species diversity of Taiwan's chondrichthyan fauna is comparable to that of other adjacent marine zoogeographic hotspots, e.g. Japan (126 shark, 75 batoid, 11 chimaeroid species) and the Philippines (81 shark, 46 batoid, 2 chimaeroid species). The Carcharhiniformes, Squaliformes, Myliobatiformes, and Rajiformes are the most dominant orders in terms of abundance and species-richness within this region. Each of these groups may increase in relative diversity with improved taxonomic resolution resulting from the incorporation of molecular tools and renewed morphological studies. Improved identification of Taiwan's chondrichthyan fauna will aid in developing better conservation and management practices. © 2013 Magnolia Press., Export Date: 11 February 2014, Source: Scopus
- Author
- Ebert, Ho, White, De Carvalho
- Date
- 2013-01-01T00:00:00Z
- Title
- A new species of Malthopsis (Lophiiformes: Ogcocephalidae) from the western Atlantic Ocean,
- Description
- A new species of Malthopsis is described from the western Atlantic Ocean, the first Malthopsis known from anywhere outside the Indo-western Pacific region except for Hawaii. Of 25 depth records, all were 275-475 m except one, which was 91 m., Cited By (since 1996):4, CODEN: BMRSA, , , Fish and Fisheries
- Author
- Bradbury
- Date
- 1998-01-01T00:00:00Z
- Title
- The effects of Cu on the adenylate energy charge of open ocean phytoplankton,
- Description
- The effects of short-term, acute Cu exposure (6 h) on the adenylate energy charge (EC A) of open-ocean phytoplankton populations (northeastern equatorial Pacific) were investigated. Energy charge remained at ̃0.77 over the range of Cu additions (0.025 - 5.μg l -1), even though 14C uptake and total adenylate levels (ATP + ADP + AMP) were reduced by as much as 60%. These findings suggest that EC A alone is not a sensitive indicator of acute sublethal metal effects on phytoplankton. © 1983 IRL Press Ltd., Cited By (since 1996):1, Oceanography, CODEN: JPLRD, ,
- Author
- Fitzwater, Knauer, Martin
- Date
- 1983-01-01T00:00:00Z
- Title
- Assessment of MERIS reflectance data as processed with SeaDAS over the European seas,
- Description
- The uncertainties associated with MERIS remote sensing reflectance (R RS) data derived from the SeaWiFS Data Analysis System (SeaDAS) are assessed with field observations. In agreement with the strategy applied for other sensors, a vicarious calibration is conducted using in situ data from the Marine Optical BuoY offshore Hawaii, and leads to vicarious adjustment factors departing from 1 by 0.2% to 1.6%. The three field data sets used for validation have been collected at fixed stations in the northern Adriatic Sea and the Baltic Sea, and in a variety of European waters in the Baltic, Black, Mediterranean and North Seas. Excluding Baltic waters, the mean absolute relative difference |Psi;| between satellite and field data is 10-14% for the spectral interval 490-560 nm, 16-18% at 443 nm, and 24-26%at413 nm. In the Baltic Sea, the |Psi;| values are much higher for the blue bands characterized by low RRS amplitudes, but similar or lower at 560 and 665 nm. For the three validation sets, the root-mean-square differences decrease from approximately 0.0013 sr -1 at 413 nm to 0.0002 sr -1 at 665 nm, and are found similar or lower than those obtained for SeaWiFS or MODIS-Aqua. As derived from SeaDAS, the RRS records associated with these three missions thus provide a multi-mission data stream of consistent accuracy. © 2011 Optical Society of America., Cited By (since 1996):4, Oceanography, ,
- Author
- Mélin, Zibordi, Berthon, Bailey, Franz, Voss, Flora, Grant
- Date
- 2011-01-01T00:00:00Z
- Title
- Characterizing source sink dynamics with genetic parentage assignments,
- Description
- Source-sink dynamics have been suggested to characterize the population structure of many species, but the prevalence of source-sink systems in nature is uncertain because of inherent challenges in estimating migration rates among populations. Migration rates are often difficult to estimate directly with demographic methods, and indirect genetic methods are subject to a variety of assumptions that are difficult to meet or to apply to evolutionary timescales. Furthermore, such methods cannot be rigorously applied to high-gene-flow species. Here, we employ genetic parentage assignments in conjunction with demographic simulations to infer the level of immigration into a putative sink population. We use individual-based demographic models to estimate expected distributions of parent-offspring dyads under competing sink and closed-population models. By comparing the actual number of parent-offspring dyads (identified from multilocus genetic profiles) in a random sample of individuals taken from a population to expectations under these two contrasting demographic models, it is possible to estimate the rate of immigration and test hypotheses related to the role of immigration on population processes on an ecological timescale. The difference in the expected number of parent-offspring dyads between the two population models was greatest when immigration into the sink population was high, indicating that unlike traditional population genetic inference models, the highest degree of statistical power is achieved for the approach presented here when migration rates are high. We used the proposed genetic parentage approach to demonstrate that a threatened population of Marbled Murrelets (Brachyramphus marmotus) appears to be supplemented by a low level of immigration (∼2-6% annually) from other populations. © 2008 by the Ecological Society of America., Cited By (since 1996):20, Marine Mammals, Birds & Turtles, CODEN: ECOLA, ,
- Author
- Peery, Beissinger, House, Bérubé, Hall, Sellas, Palsbøll
- Date
- 2008-01-01T00:00:00Z
- Title
- Diet, feeding behaviour and habitat utilisation of the blue stingray Dasyatis chrysonota (Smith, 1828) in South African waters,
- Description
- Analysis of stomach contents for Dasyatis chrysonota revealed that diet varied with size and habitat. The diet of all size classes in the surf zone was comprised primarily of Callianassa spp., Donax spp. and unidentified polychaete species. The medium and large size classes fed primarily on Donax spp., whereas the very large size class fed mainly on Callianassa spp. Polychaetes were of secondary importance as prey for the medium size class. The diet of D. chiysonota in the nearshore zone consisted mainly of Balanoglossus capensis and Callianassa spp. Balanoglossus capensis decreased from an index of relative importance (IRI) of 75.3% for the medium size class to 59.9% for the very large size class, whereas Callianassa spp. increased from 22.8% to 39.4% between the medium and the very large size classes. The offshore zone was the only area in which small size class D. chrysonota were caught. The diet of these small D. chrysonota was primarily polychaetes and amphipods. Polychaetes increased in importance in the medium size class, but declined in each successively larger size class. Conversely, Pterygosquilla armata capensis became the single most important prey item for the very large size class, comprising an IRI of 50.9%. The behaviour pattern used by D. chrysonota to locate and extract prey is described., Cited By (since 1996):27, Fish and Fisheries, CODEN: AJMFA, ,
- Author
- Ebert, Cowley
- Date
- 2003-01-01T00:00:00Z
- Title
- Comparison of seastar (Asteroidea) fauna across island groups of the Scotia Arc,
- Description
- The Antarctic shelf fauna is isolated from other continental shelf faunas both physically by distance, and oceanographically by the Antarctic circumpolar current (ACC). To elucidate the relative importance of these two isolating mechanisms, we used the seastar fauna of the south-Atlantic sub-Antarctic islands to address the hypothesis that the ACC is dominant in controlling the distribution pattern of Antarctic fauna. We expected that seastar faunas from islands on the high latitude side of the ACC would show more similarities to each other than to faunas from islands on the low latitude side. The alternative isolation by distance model predicted that the island furthest from others would have the most unique fauna. For shelf-depth (<500 m) Asteroidea of the Scotia Arc region, assemblages were more similar between islands on each side of the ACC barrier than islands that were closer together, and this pattern was caused by differences in abundance of a few ubiquitous species. © 2006 Springer-Verlag., Cited By (since 1996):3 Invertebrates, ,
- Author
- Kim, Thurber
- Date
- 2007-01-01T00:00:00Z
- Title
- Genetic patterns across multiple introductions of the globally invasive crab genus Carcinus,
- Description
- The European green crab Carcinus maenas is one of the world's most successful aquatic invaders, having established populations on every continent with temperate shores. Here we describe patterns of genetic diversity across both the native and introduced ranges of C. maenas and its sister species, C. aestuarii, including all known non-native populations. The global data set includes sequences from the mitochondrial cytochrome c oxidase subunit I gene, as well as multilocus genotype data from nine polymorphic nuclear microsatellite loci. Combined phylogeographic and population genetic analyses clarify the global colonization history of C. maenas, providing evidence of multiple invasions to Atlantic North America and South Africa, secondary invasions to the northeastern Pacific, Tasmania, and Argentina, and a strong likelihood of C. maenas x C. aestuarii hybrids in South Africa and Japan. Successful C. maenas invasions vary broadly in the degree to which they retain genetic diversity, although populations with the least variation typically derive from secondary invasions or from introductions that occurred more than 100 years ago., Cited By (since 1996):54, CODEN: MOECE, ,
- Author
- Darling, Bagley, Roman, Tepolt, Geller
- Date
- 2008-01-01T00:00:00Z
- Title
- Sedimentation and composition of wall communities in Alaskan fjords,
- Description
- The effects of suspended sediments on the composition of wall communities in Alaskan fjords were investigated by quantitative assessment of underwater photo-quadrats. In fjords with actively retreating tidewater glaciers, suspended sediment levels were extremely high at the heads and were exponentially lower at the mouths. Fjords without glaciers had low suspended sediment levels throughout. The per cent cover and number of species were lowest where sedimentation was highest, at the heads of glacial fjords. Here the wall communities were dominated by a sparse cover of small serpulid worms. Richer communities comprising mostly algae, sponges, hydroids, bryozoans, tunicates and brachiopods were found in fjords without glaciers, and at the mouths of glacial fjords. There was a positive correlation between water clarity and community composition along a gradient from heads to the mouths of fjords with high suspended sediment levels., Cited By (since 1996):3, Invertebrates, Ecology, CODEN: POBID, ,
- Author
- Carney, Oliver, Armstrong
- Date
- 1999-01-01T00:00:00Z
- Title
- Dissolved oxygen dynamics in a eutrophic estuary, Upper Newport Bay, California,
- Description
- Eutrophication often causes hypoxia in estuarine and coastal systems, but the mechanisms that control hypoxic events vary among estuaries and are often difficult to discern. We monitored surface and bottom dissolved oxygen (DO) in the Upper Newport Bay (UNB), a tidally mixed estuary in southern California subject to anthropogenic nutrient loading, eutrophication and hypoxia. Our goal was to identify the environmental factors regulating DO dynamics. Six hypoxic events occurred between June and November and were associated with a combination of low solar radiation, increased freshwater discharge following precipitation, and enhanced haline stratification during reduced tidal range periods. At the head of the estuary, high macroalgal biomass and pronounced haline stratification resulted in high DO in the surface layer and low DO in the bottom layer. Oxygen-rich and oxygen-poor waters were transported down-estuary by ebb tides, resulting in DO heterogeneity throughout the UNB. Cross-wavelet analysis illustrated the down-estuary propagation of high/low DO signal correlated with the phases of diurnal photosynthetic and semi-diurnal tidal cycles. © 2009 Elsevier Ltd. All rights reserved., Cited By (since 1996):10, Oceanography, CODEN: ECSSD, ,
- Author
- Nezlin, Kamer, Hyde, Stein
- Date
- 2009-01-01T00:00:00Z
- Title
- A revision of the western North Pacific swellsharks, genus Cephaloscyllium Gill 1862 (Chondrichthyes: Carcharhiniformes: Scyliorhinidae), including descriptions of two new species.,
- Description
- The genus Cephaloscyllium Gill 1862 (Chondrichthyes, Carcharhiniformes, Scyliorhinidae) until recently had only two species recognized, C. isabellum [= C. umbratile (Jordan & Fowler 1903)] and C. fasciatum Chan 1966, from the western North Pacific (WNP), with one dubious species, C. formosanum, having been described by Teng in 1962. Recently, three additional species were described, C. circulopullum Yano et al. 2005, C. sarawakensis Yano et al. 2005, and C. parvum Inoue & Nakaya 2006 from this region. Here we present a revision of this genus for the WNP, including redescriptions of C. fasciatum and C. umbratile based on the holotypes, a re-examination of the recently described species, and descriptions of two new species from Taiwan. Cephaloscyllium umbratile can be distinguished from its congeners based on maximum size, length of first dorsal-fin base, anal-caudal space, and dorsal-caudal space. We conclude, based on a comparison of C. parvum and C. sarawakensis, that the former is a junior synonym of the latter species. The two new Taiwanese species can be separated from other WNP species by color pattern, shape of the anterior nasal flap, anal and dorsal-fin size, internarial width, and mouth size. Finally, we present a revised dichotomous key to the WNP Cephaloscyllium recognizing six contemporary taxa: C. circulopullum, C. fasciatum, C. sarawakensis, C. umbratile, C. pardelotum sp. nov. and C. maculatum sp. nov. Copyright © 2008 Magnolia Press., Cited By (since 1996):2, , , Fish and Fisheries
- Author
- Schaaf-Da Silva, Ebert
- Date
- 2008-01-01T00:00:00Z
- Title
- Improvement of the pre-deployment net closure procedure used with opening/closing plankton nets,
- Description
- The construction of a closing device to be used during the deployment of phyto-zooplankton nets utilizing General Oceanics-type opening/closing mechanisms is described. This device (the cowl) decreases system set-up time, decreases contamination from ambient particles while waiting for deployment, protects the net from mechanical tears during descent, and increases system reliability., Cited By (since 1996):2, CODEN: JPLRD, ,
- Author
- Tuel, Knauer
- Date
- 1982-01-01T00:00:00Z
- Title
- The tail of the Storegga Slide: Insights from the geochemistry and sedimentology of the Norwegian Basin deposits
- Description
- Deposits within the floor of the Norwegian Basin were sampled to characterize the deposition from the Storegga Slide, the largest known Holocene-aged continental margin slope failure complex. A 29 to 67 cm thick veneer of variable-coloured, finely layered Holocene sediment caps a homogeneous, extremely well-sorted, poorly consolidated, very fine-grained, grey-coloured sediment section that is >20 m thick on the basin floor. This homogeneous unit is interpreted to represent the uppermost deposits generated by a gravity flow associated with the last major Storegga Slide event. Sediments analogous to the inferred source material of the slide deposits were collected from upslope on the Norwegian Margin. Sediments sampled within the basin are distinguishable from the purported source sediments, suggesting that size sorting has significantly altered this material along its flow path. Moreover, the very fine grain size (3·1 ± 0·3 μm) suggests that the >20 m thick homogeneous unit which was sampled settled from suspension after the turbulent flow was over. Although the turbulent phase of the gravity flow that moved material out into the basin may have been brief (days), significantly more time (years) is required for turbid sediments to settle and dewater and for the new sea floor to be colonized with a normal benthonic fauna. Pore water sulphate concentrations within the uppermost 20 m of the event deposit are higher than those normally found in sea water. Apparently the impact of microbial sulphate reduction over the last ca 8·1 cal ka bp since the re-deposition of these sediments has not been adequate to regenerate a typical sulphate gradient of decreasing concentration with sub-bottom depth. This observation suggests low rates of microbial reactions, which may be attributed to the refractory carbon composition in these re-deposited sediments. © 2010 The Authors. Journal compilation © 2010 International Association of Sedimentologists., Cited By (since 1996):1, Rocks & Cores
- Author
- Paull, Ussler III, Holbrook, Hill, Haflidason, Winters, Lorenson, Aiello, Johnson, Lundsten
- Date
- 2010-01-01T00:00:00Z
- Title
- Energetic composition, biomass, and chemical defense in the common Antarctic nemertean Parborlasia corrugatus McIntosh,
- Description
- Parborlasia corrugatus McIntosh is a large, abundant, epibenthic antarctic nemertean which represents a considerable source of nutrition for predators. The energetic composition of adult body tissues (kJ·g -1 dry wt) is comprised primarily of energy derived from protein (11.4 kJ NaOH-insoluble, 6 kJ NaOH-soluble). Energy units associated with lipid (4.3 kJ) and carbohydrate (0.2 kJ) are much lower. Based on calculations of the energetic composition of whole body tissues, and a density of 0.3 ind·m -2, mean population energetic density is estimated to be 65 kJ·m -2. These values are often significantly higher as P. corrugatus aggregates when feeding. Despite their high abundance, nemerteans are not preyed upon and appear to be chemically defended. Sperm of the antarctic sea urchin Sterechinus neumeyeri (Meissner) were killed when exposed to a 3% aqueous extract of whole nemertean body tissues. In laboratory feeding experiments, two common species of antarctic fish showed significant rejection of nemerteans. Its toxic and feeding-deterrent characteristics are probably the result of the epithelial production of copious acidic mucus (pH = 3.5), although other toxic or noxious metabolites may be present. These results indicate that P. corrugatus, an important scavenger in antarctic benthic systems, is abundant, high in nutrients and energy content, and could be judged on this basis as a high-quality prey item. Nonetheless, due to its chemical defense, potential predators may avoid ingestion of this species., Cited By (since 1996):28, Invertebrates, Antarctica, CODEN: JEMBA, ,
- Author
- Heine
- Date
- 1991-01-01T00:00:00Z
- Title
- Rammed by the Exxon Valdez,
- Description
- , , ,
- Author
- Foster
- Date
- 1991-01-01T00:00:00Z
- Title
- Phylogenetic relationships of yessotoxin-producing dinoflagellates, based on the large subunit and internal transcribed spacer ribosomal DNA domains
- Description
- Yessotoxin (YTX) is a globally distributed marine toxin produced by some isolates of the dinoflagellate species Protoceratium reticulatum, Lingulodinium polyedrum, and Gonyaulax spinifera within the order Gonyaulacales. The process of isolating cells and testing each isolate individually for YTX production during toxic blooms are labor intensive, and this impedes our ability to respond quickly to toxic blooms. In this study, we used molecular sequences from the large subunit and internal transcribed spacer genomic regions in the ribosomal operon of known YTX-producing dinoflagellates to determine if genetic differences exist among geographically distinct populations or between toxic and nontoxic isolates within species. In all analyses, all three YTX-producing species fell within the Gonyaulacales order in agreement with morphological taxonomy. Phylogenetic analyses of available rRNA gene sequences indicate that the capacity for YTX production appears to be confined to the order Gonyaulacales. These findings indicate that Gonyaulacoloid dinoflagellate species are the most likely to produce YTX and thus should be prioritized for YTX screening during events. Dinoflagellate species that fall outside of the Gonyaulacales order are unlikely to produce YTX. Although the rRNA operon offers multiple sequence domains to resolve species level diversification within this dinoflagellate order, these domains are not sufficiently variable to provide robust markers for YTX toxicity. © 2009, American Society for Microbiology. All Rights Reserved., Cited By (since 1996):8, CODEN: AEMID, Downloaded from: http://aem.highwire.org/content/75/1/54.full.pdf+html (13 June 2014).
- Author
- Howard, Smith, Kudela
- Date
- 2009-01-01T00:00:00Z
- Title
- Exploring the davidson seamount: Combining science, public outreach, and resource management,
- Description
- Scientific information is often interpreted to the public long after it has been discovered. NOAA programs and private organizations are interested in more immediate sharing of information with the public so that it can be more effectively used in resource management. The Davidson Seamount is an underwater volcano off the coast of Central California, and recent advances in technology provide the opportunity to explore and characterize the biology of this deep-sea habitat. With an interdisciplinary team of scientists, outreach specialists, and resource managers, this exploration was presented to the public as it was happening with daily updates on a web site. The public also interacted by e-mail with the explorers during the expedition. Huge corals and sponges, deep-water fishes, and the technology needed to study this deep, dark habitat particularly engaged the public, resource managers, and scientists alike. Following the cruise there was national media interest in discoveries from the expedition, not only because the findings were spectacular, but because significant efforts were made to provide the media with access to the explorers and images of the findings. Resource managers are already using summary information from the cruise in processes that may potentially protect Davidson Seamount habitats. Even before the scientific data has been completely analyzed, the public and resource managers have been engaged in a healthy process of information sharing. In characterizing the biology of Davidson Seamount, we found that this model of an interdisciplinary expedition effectively integrated new scientific information into public understanding and management options for a unique area., , ,
- Author
- DeVogelaere, Kochevar, Tamburri, Cailliet, Burton, Benson, Douros
- Date
- 2005-01-01T00:00:00Z
- Title
- Damage and recovery in intertidal Fucus gardneri assemblages following the Exxon Valdez oil spill,
- Description
- Cited By (since 1996):19 Seaweeds, CODEN: MESED, In March 1989, the 'Exxon Valdez' spilled over 10 million gallons (ca 38 million I) of crude oil into Prince William Sound, Alaska , USA. The spill was followed by massive clean-up using hot seawater at high pressure as well as other mechanical and chemical techniques. We studied initial damage and subsequent recovery in the upper margin of the Fucus gardneri assemblage on protected shores by comparing sites that were unoiled, oiled and cleaned with hot water at high pressure, and oiled but less intensely cleaned. F. gardneri cover averaged 80% on unoiled sites but< 1 % on all oiled and cleaned sites 18 mo after the spill. The abundances of barnacles, littorine snails and limpets varied among sites and species, and this variation was associated in part with differences in their life histories. F. gardneri cover was still extremely low on oiled and cleaned sites 2.5 yr after the spill. Holdfasts that persisted after cleaning did not resprout. F. gardneri recruitment was lowest at intensely cleaned sites, and most recruits occurred in cracks near adults. Recruits were less abundant under adult canopies but placing canopies over recruits did not decrease their survivorship over 5 mo. Natural weathering of tar was rapid, with most marked patches gone in less than 1 yr. We conclude that intense mechanical cleaning following this oil spill increased damage and slowed recovery. Such methods should be avoided if reduction of environmental damage is the primary objective of post-spill management decisions. The recovery of F. gardneri at its upper margin might be enhanced by devices that retain moisture and increase substratum rugosity., ,
- Author
- Devogelaere, Foster
- Date
- 1994-01-01T00:00:00Z
- Title
- Techniques for enhancing vertebral bands in age estimation of California elasmobranchs
- Description
- Vertebrae from 1,152 elasmobranchs representing 22 species were collected between 1979 and 1981 to assess methods of enhancing incremental growth bands for age estimation. Thus far, we have tested methods previouslyreported in the literature, and have developed new procedures to enhance growth increments on 684 individuals of 14 species of elasmobranchs. Silver nitrate impregnation, X-radiograpby, and cedarwood oil clearing were the most successful techniques. Less effeetive were alizarin red staining, paraffin impregnation, alcohol immersiorn, and formic acid etching. Methods for preparing vertebrae and enhancing and counting growth increments are presented, and the problems associated with interpreting tile annual nature of such counts are discussed.
- Author
- Cailliet, Martin, Kusher, Wolf, Welden, Prince, Pulos
- Date
- 1983-01-01T00:00:00Z
- Title
- Chlamydoselachus africana, a new species of frilled shark from southern Africa (Chondrichthyes, Hexanchiformes, Chlamydoselachidae),
- Description
- Frilled sharks (Chondrichthyes, Hexanchiformes, Chlamydoselachidae), long believed to be a monotypic family and genus, consisting of a single wide ranging species, Chlamydoselachus anguineus (Garman, 1884), is now known to contain at least two species. A new species of frilled shark, Chlamydoselachus africana, sp. nov., is described from five specimens collected from southern Africa. The new species, although difficult to distinguish externally from the well known C. anguineus, differ internally by the structural differences in the chondrocranium, lower total vertebral and spiral valve counts, and pectoral-fin radial counts. The new species, Chlamydoselachus africana, is known from off southern Angola, Namibia, and South Africa. © 2009 · Magnolia Press., Cited By (since 1996):3, Fish and Fisheries, ,
- Author
- Ebert, Compagno
- Date
- 2009-01-01T00:00:00Z
- Title
- Proliferative responses of harbor seal (Phoca vitulina) T lymphocytes to model marine pollutants,
- Description
- In recent years, population declines related to viral outbreaks in marine mammals have been associated with polluted coastal waters and high tissue concentrations of certain persistent, lipophilic contaminants. Such observations suggest a contributing role of contaminant-induced suppression of cell-mediated immunity leading to decreased host resistance. Here, we assessed the effects of the prototypic polycyclic aromatic hydrocarbon (PAH), benzo[a]pyrene (B[a]P), and two polychlorinated biphenyls (PCBs), CB-156 and CB-80, on the T-cell proliferative response to mitogen in harbor seal peripheral lymphocytes. Despite the variability associated with our samples from free-ranging harbor seals, we observed a clear suppressive effect of B[a]P (10 uM) exposure on T cell mitogenesis. Exposures to 10 uM CB-156 and CB-80, and 1.0 and 0.1 uM B[a]P, did not produce significant depression in lymphoproliferation. Exposure to the model PAH at 10 uM resulted in a 61% (range 34-97%) average reduction in lymphoproliferation. We were able to rule out a direct cytotoxic effect of B[a]P, indicating that observed effects were due to altered T cell function. Based on our in vitro results, we hypothesize that extensive accumulation of PAH by top-trophic-level marine mammals could alter T cell activation in vivo and impaired cell-mediated immunity against viral pathogens., Cited By (since 1996):12, CODEN: DEIME, ,
- Author
- Neale, Van De Water, Harvey, Tjeerdema, Gershwin
- Date
- 2002-01-01T00:00:00Z