The Behavioral Response Of Harbor Seals To Seasonal Prey Pulses Of Spawning Pacific Herring, 2010 Western Washington University
The Behavioral Response Of Harbor Seals To Seasonal Prey Pulses Of Spawning Pacific Herring, Austen C. Thomas
WWU Graduate School Collection
The Pacific harbor seal (Phoca vitulina) is a noteworthy omission from the list of predators that aggregate at herring spawning sites, despite strong suggestive evidence that they are likely to respond to herring pulses. Working with the hypothesis that spawning herring aggregations are seasonally important prey for harbor seals, we tested several predictions using an analysis of harbor seal prey remains, GPS telemetry, and satellite-linked time/depth recorder data. Contrary to predictions, herring in harbor seal diet was comprised of 77% juveniles and 23% adults in the spawn season, versus 33% juveniles and 67% adults in the post-spawn season. Seal ...
Age Determination Of The Sixgill Shark From Hard Parts Using A Series Of Traditional And Novel Approaches, 2010 Western Washington University
Age Determination Of The Sixgill Shark From Hard Parts Using A Series Of Traditional And Novel Approaches, S. Jeffrey (Steven Jeffrey) Campbell
WWU Graduate School Collection
Necessary to the management of any species of fish is the ability to determine age in individuals. Age information is used to establish growth rates, longevity, age at maturity, and population age structure, and to predict how population demographics will change over time. For most species of fish, reliable aging techniques have been in use since the early 20th century. Most boney fish are aged by counting bands of calcium phosphate hydroxyapatite that form over time in skeletal hard parts such as otoliths, fin-spines, and scales, which can be used as proxies for age in years. Fishes in the Class ...
Polyunsaturated Aldehyde Production By A Temporally Varying Field Assemblage Of Diatoms In The San Juan Island Archipelago: Can Diatom Metabolites Affect Microzooplankton Grazing?, 2010 Western Washington University
Polyunsaturated Aldehyde Production By A Temporally Varying Field Assemblage Of Diatoms In The San Juan Island Archipelago: Can Diatom Metabolites Affect Microzooplankton Grazing?, Blair M. (Blair Michael) Paul
WWU Graduate School Collection
The success of diatoms in a wide range of global habitats, together with common observations of the post-bloom sinking of diatom biomass, indicates that this taxon has evolved a mechanism to reduce the largest loss process for phytoplankton in the ocean, microzooplankton grazing. Recent research has shown that polyunsaturated aldehydes (PUAs), lipid oxidation products generated by various species of diatoms, can reduce copepod fecundity and egg hatching success. This leads to the question of whether PUAs adversely affect the major global consumers of phytoplankton, microzooplankton. In the late spring to early fall 2007, I used the seawater dilution technique to ...
Impacts Of The Spotted Spiny Lobster (Panulirus Guttatus) On The Long-Spined Sea Urchin (Diadema Antillarum) And Patch Reef Communities In The Florida Keys, Meredith D. Kintzing
Biological Sciences Theses & Dissertations
Caribbean coral reefs have undergone a phase shift from a system dominated by corals to one where algae are pervasive. This shift was precipitated by the loss of herbivores, including the mass mortality of the long spined sea urchin (Diadema antillarum), coupled with disease and the recruitment failure of hermatypic corals. Diadema populations have recovered in some areas of the Caribbean, but are still below historical levels in the Florida Keys, likely due to low larval supply coupled with predation on juveniles. Lobsters are sea urchin predators in other systems and the spotted spiny lobster (Panulirus guttatus ) is abundant on ...
Evidence For Greater Oxygen Decline Rates In The Coastal Ocean Than In The Open Ocean, 2010 Virginia Institute of Marine Science
Evidence For Greater Oxygen Decline Rates In The Coastal Ocean Than In The Open Ocean, D. Gilbert, N. N. Rabalais, R. J. Diaz, J. Zhang
In the global ocean, the number of reported hypoxic sites (oxygen < 30% saturation) is on the rise both near the coast and in the open ocean. But unfortunately, most of the papers on hypoxia only present oxygen data from one or two years, so that we often lack a long-term perspective on whether oxygen levels at these locations are decreasing, steady or increasing. Consequently, we cannot rule out the possibility that many of the newly reported hypoxic areas were hypoxic in the past, and that the increasing number of hypoxic areas partly reflects increased research and monitoring efforts. Here we address this shortcoming by computing oxygen concentration trends in the global ocean from published time series and from time series that we calculated using a global oxygen database. Our calculations reveal that median oxygen decline rates are more severe in a 30 km band near the coast than in the open ocean (> 100 km from the coast). Percentages of oxygen time series with negative oxygen trends are also greater in the coastal ocean than in the open ocean. Finally, a significant difference between median published oxygen trends and median trends calculated from raw oxygen data suggests the existence of a publication bias in favor of negative trends in the open ocean.
Molecular Identification, Phylogeny And Geographic Distribution Of Brazilian Mangrove Oysters (Crassostrea), Aline Grasielle Costa De Melo, Kimberly S. Reece
Oysters (Ostreidae) manifest a high degree of phenotypic plasticity, whereby morphology is of limited value for species identification and taxonomy. By using molecular data, the aim was to genetically characterize the species of Crassostrea occurring along the Brazilian coast, and phylogenetically relate these to other Crassostrea from different parts of the world. Sequencing of the partial cytochrome oxidase c subunit I gene (COI), revealed a total of three species of Crassostrea at 16 locations along the Brazilian coast. C. gasar was found from Curuca (Para state) to Santos (Sao Paulo state), and C. rhizophorae from Fortim (Ceara state) to Florianopolis ...
Phocine Distemper Virus Induced Demyelination In The Spinal Cord Of Infected Harbor Seals (Phoca Vitulina), 2010 University of New England
Phocine Distemper Virus Induced Demyelination In The Spinal Cord Of Infected Harbor Seals (Phoca Vitulina), Thomas Siemens
All Theses And Dissertations
Phocine Distemper Virus (PDV) is a Morbillivirus that has been responsible for the death of approximately 40,000 phocid seals in the last three decades. The most commonly reported pathology is virally induced demyelination of the cerebrum and brainstem which leaves axons bare and limits their conductivity of action potentials. While these conditions have been studied at length, there is little mention of spinal cord involvement. This study aims to determine whether demyelination found in the brainstem continues into the cervical spinal cord. The results indicate that demyelination in the cervical spinal cord does not occur alongside the brainstem. It ...
Bycatch Reduction Device Conserves Diamondback Terrapin Without Affecting Catch Of Blue Crab, 2010 Virginia Institute of Marine Science
Bycatch Reduction Device Conserves Diamondback Terrapin Without Affecting Catch Of Blue Crab, Megan A. Rook, Romuald N. Lipcius, Bret M. Bronner, Randolph M. Chambers
Bycatch mortality of non-target species in fisheries is a major threat to the conservation and restoration of marine and estuarine species. Attempts to reduce bycatch by fitting fishing gear with excluder devices have typically been met with resistance due to reductions in catch of target species. We examined the possibility that conservation and fishery goals could be met simultaneously. In lower Chesapeake Bay, we tested a mechanism for reducing bycatch of diamondback terrapin Malaclemys terrapin in blue-crab traps without affecting crab catch. Over 23 sampling dates during summer 2008, we compared terrapin captures at 2 shallow-water sites typical of recreational ...
Estimation Of Juvenile Striped Bass Relative Abundance In The Virginia Portion Of Chesapeake Bay, January 2009-December 2009 : Annual Progress Report, 2010 Virginia Institute of Marine Science
Estimation Of Juvenile Striped Bass Relative Abundance In The Virginia Portion Of Chesapeake Bay, January 2009-December 2009 : Annual Progress Report, Leonard S. Machut, Mary C. Fabrizio
The 2009 striped bass juvenile abundance index is 8.42 and is not significantly different from the historic average of 7.54. Additional methods of calculating the regional index support this conclusion. Catches in the York River were nearly identical to its historic average. Although the James River catches were higher and the Rappahannock River catches were lower than historic averages, they were not significantly so. Striped bass catches at auxiliary stations provide greater spatial coverage of the nursery grounds and suggest that juvenile striped bass were broadly distributed throughout the sampling area in 2009.
Observations Of Distribution, Size, And Sex Ratio Of Mature Blue Crabs, Callinectes Sapidus, From A Chesapeake Bay Tributary In Relation To Oyster Habitat And Environmental Factors, 2010 Virginia Institute of Marine Science
Observations Of Distribution, Size, And Sex Ratio Of Mature Blue Crabs, Callinectes Sapidus, From A Chesapeake Bay Tributary In Relation To Oyster Habitat And Environmental Factors, Jm Harding, R Mann
Blue crabs Callinectes sapidus (Rathbun, 1896) > 100 mm carapace width were sampled from a constructed oyster reef (1996 and 1997), a sand bar (1997) and a natural oyster bar (1997) in the Piankatank River, Chesapeake Bay, USA to describe habitat use, sex ratios, and demographics across a gradient of habitat types. Patterns of blue crab catch-per-unit-effort (CPUE), and demographics were similar on the oyster reef in 1996 and 1997. Average annual CPUE on the reef was 6-8 crabs pot(-1) with maximum CPUE of 15 crabs pot(-1). Daylength and water temperature significantly affected reef CPUE with more crabs observed ...
Virginia Game Fish Tagging Program Annual Report 2009, 2010 Virginia Institute of Marine Science
Virginia Game Fish Tagging Program Annual Report 2009, John A. Lucy, Lewis Gillingham
Through 2009, the Virginia Game Fish Tagging Program has maintained a 15-year database for tagged and recaptured fish. The program is a cooperative project of the Virginia Saltwater Fishing Tournament (under the Virginia Marine Resources Commission/VMRC) and the Virginia Institute of Marine Science (VIMS) of the College of William and Mary (under VIMS Sea Grant Marine Extension Program).
The Status Of Virginia's Public Oyster Resource 2009, 2010 Virginia Institute of Marine Science
The Status Of Virginia's Public Oyster Resource 2009, Melissa Southworth, Juliana Harding, Roger Mann
This report summarizes data collected during 2009 in the Virginia portion of the Chesapeake Bay. The report is composed of two parts, part one, oyster recruitment (shell string) in Virginia and part two, dredge survey of selected oyster bars in Virginia.
Assessing The Apparent Imbalance Between Geochemical And Biochemical Indicators Of Meso- And Bathypelagic Biological Activity: What The @$#! Is Wrong With Present Calculations Of Carbon Budgets?, 2010 Virginia Institute of Marine Science
Assessing The Apparent Imbalance Between Geochemical And Biochemical Indicators Of Meso- And Bathypelagic Biological Activity: What The @$#! Is Wrong With Present Calculations Of Carbon Budgets?, Ab Burd, Da Hansell, Dk Steinberg, Tr Anderson, J Aristegui
Metabolic activity in the water column below the euphotic zone is ultimately fuelled by the vertical flux of organic material from the surface. Over time, the deep ocean is presumably at steady state, with sources and sinks balanced. But recently compiled global budgets and intensive local field studies suggest that estimates of metabolic activity in the dark ocean exceed the influx of organic substrates. This imbalance indicates either the existence of unaccounted sources of organic carbon or that metabolic activity in the dark ocean is being over-estimated. Budgets of organic carbon flux and metabolic activity in the dark ocean have ...
Shearwater Foraging In The Southern Ocean: The Roles Of Prey Availability And Winds, 2009 San Jose State University
Shearwater Foraging In The Southern Ocean: The Roles Of Prey Availability And Winds, B Raymond, Scott A. Shaffer, S Sokolov, E Woehler, D P. Costa, L Einoder, M Hindell, G Hosie, M Pinkerton, P M. Sagar, D Scott, A Smith, D R. Thompson, C Vertigan, H Weimerskirch
Scott A. Shaffer
Background Sooty (Puffinus griseus) and short-tailed (P. tenuirostris) shearwaters are abundant seabirds that range widely across global oceans. Understanding the foraging ecology of these species in the Southern Ocean is important for monitoring and ecosystem conservation and management. Methodology/Principal Findings Tracking data from sooty and short-tailed shearwaters from three regions of New Zealand and Australia were combined with at-sea observations of shearwaters in the Southern Ocean, physical oceanography, near-surface copepod distributions, pelagic trawl data, and synoptic near-surface winds. Shearwaters from all three regions foraged in the Polar Front zone, and showed particular overlap in the region around 140°E ...
Niche Partitioning Among And Within Sympatric Tropical Seabirds Revealed By Stable Isotope Analysis, 2009 Stanford University
Niche Partitioning Among And Within Sympatric Tropical Seabirds Revealed By Stable Isotope Analysis, H S. Young, D J. Mccauley, R Dirzo, R D. Dunbar, Scott A. Shaffer
Scott A. Shaffer
The low productivity and unpredictable nature of resources in tropical waters would appear to make resource partitioning among predators difficult. Yet, stable isotope data from the present study suggest that substantial resource partitioning occurs among tropical seabird communities, both between and within species. In the present study, we compared δ13C and δ15N levels among 8 sympatric tropical seabird species. For a subset of these species, we also examined isotopic levels across years, breeding periods, and sexes. When breeding and non-breeding periods were both considered, we found that all species occupied distinct isotopic niches across at least one time period. Resource ...