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Genetic Analysis Of White Marlin (Tetrapturus Albidus) Stock Structure, John Graves, Jan Mcdowell
Genetic Analysis Of White Marlin (Tetrapturus Albidus) Stock Structure, John Graves, Jan Mcdowell
VIMS Articles
The genetic basis of stock structure of white marlin (Tetrapturus albidus Poey, 1860) was inferred from analyses of five tetranucleotide repeat microsatellite loci (n = 214) and the mitochondrial (mt)DNA control region (n = 99) of white marlin from four geographic regions in the Atlantic Ocean. Considerable genetic variation was present in all collections for all molecular markers. Analysis of replicate collections taken in different years from three regions revealed no significant differences in the distribution of allele frequencies among years within regions. The value of global F-statistics for both multilocus microsatellite data and mtDNA control region sequences approached significance …
Phylogeny Of Recent Billfishes (Xiphioidei), Bb Collette, Jan Mcdowell, John Graves
Phylogeny Of Recent Billfishes (Xiphioidei), Bb Collette, Jan Mcdowell, John Graves
VIMS Articles
Billfishes are genetically and morphologically distinct enough from scombroids to merit placement in a separate suborder, Xiphioidei. Two extant families are usually recognized: Xiphiidae (swordfish, Xiphias) and Istiophoridae, currently containing three genera, Istiophorus (sailfishes), Makaira (marlins), and Tetrapturus (spearfishes, white, and striped marlins). Phylogenetic analyses of molecular data from mitochondrial and nuclear gene sequences (mitochondrial control region, ND2, 12S, and nuclear MN 32 regions) show a different picture of relationships. Makaira is not monophyletic: blue marlin cluster with sailfish and placement of black marlin is unstable. Accepting the molecular phylogeny gives two possible classifications: (1) two genera: blue marlin + …
Genetic Heterogeneity Of Atlantic Bluefin Tuna Caught In The Eastern North Atlantic Ocean South Of Iceland, J Carlsson, Jr Mcdowell, Et Al
Genetic Heterogeneity Of Atlantic Bluefin Tuna Caught In The Eastern North Atlantic Ocean South Of Iceland, J Carlsson, Jr Mcdowell, Et Al
VIMS Articles
Atlantic bluefin tuna (Thunnus thynnus) are currently managed by the member nations of the International Commission for the Conservation of Atlantic Tunas (ICCAT) as distinct western and eastern stocks, separated by the 45 degrees W meridian. Previous studies of Atlantic bluefin tuna caught in the northeast Atlantic south of Nor-way suggested mixing of putative stocks in the region, based on abrupt shifts in the size and condition of fish during the fishing season. By contrast, more recent studies south of Iceland reported only small differences in size of tuna caught at different times of the season in that area. To …
Incentive-Based Approaches To Sustainable Fisheries, Rq Grafton, R Arnason, Et Al, Je Kirkley, Et Al
Incentive-Based Approaches To Sustainable Fisheries, Rq Grafton, R Arnason, Et Al, Je Kirkley, Et Al
VIMS Articles
The failures of traditional target-species management have led many to propose an ecosystem approach to fisheries to promote sustainability. The ecosystem approach is necessary, especially to account for fishery-ecosystem interactions, but by itself is not sufficient to address two important factors contributing to unsustainable fisheries: inappropriate incentives bearing on fishers and the ineffective governance that frequently exists in commercial, developed fisheries managed primarily by total-harvest limits and input controls. We contend that much greater emphasis must be placed on fisher motivation when managing fisheries. Using evidence from more than a dozen natural experiments in commercial fisheries, we argue that incentive-based …
Growth And Development Of Veined Rapa Whelk Rapana Venosa Veligers, Jm Harding
Growth And Development Of Veined Rapa Whelk Rapana Venosa Veligers, Jm Harding
VIMS Articles
Planktonic larvae of benthic fauna that can grow quickly in the plankton and reduce their larval period duration lessen their exposure to pelagic predators and reduce the potential for advection away from suitable habitats. Veined rapa whelks (Rapana venosa, Muricidae) lay egg masses that release planktonic veliger larvae from May through August in Chesapeake Bay, USA. Two groups of veliger larvae hatched from egg masses during June and August 2000 were cultured in the laboratory. Egg mass incubation time (time from deposition to hatch) ranged from 18-26 d at water temperatures between 22 degrees C and 27 degrees C. Four …
Diving Behavior And Delayed Mortality Of Olive Ridley Seat Turtles Lepidochelys Olivacea After Their Release From Longline Fishing Gear, Yonat Swimmer, Randall Arauz, Marti Mccracken, Lianne Mcnaughton, Jorge Ballestero, Mike Musyl, Keith Bigelow, Richard Brill
Diving Behavior And Delayed Mortality Of Olive Ridley Seat Turtles Lepidochelys Olivacea After Their Release From Longline Fishing Gear, Yonat Swimmer, Randall Arauz, Marti Mccracken, Lianne Mcnaughton, Jorge Ballestero, Mike Musyl, Keith Bigelow, Richard Brill
VIMS Articles
We deployed pop-off satellite archival tags (PSATs) on 14 olive ridley turtles Lepidochelys olivacea and 1 green turtle Chelonia mydas in the eastern tropical Pacific Ocean between November 2001 and June 2003 to determine dive behavior and post-release mortality following interactions with longline fishing gear. Nine olive ridleys and 1 green turtle were captured by longline fishing gear, and 5 free swimming olive ridleys were hand-captured at the surface to serve as controls. Hooks were removed from all longline-caught turtles, with the exception of 1 olive ridley turtle. PSATs remained on control- and longline-caught olive ridleys for an average of …
Age And Growth Of Wild Suminoe (Crassostrea Ariakensis, Fugita 1913) And Pacific (C-Gigas, Thunberg 1793) Oysters From Laizhou Bay, China, Jm Harding, Roger L. Mann
Age And Growth Of Wild Suminoe (Crassostrea Ariakensis, Fugita 1913) And Pacific (C-Gigas, Thunberg 1793) Oysters From Laizhou Bay, China, Jm Harding, Roger L. Mann
VIMS Articles
Shell height at age estimates from Suminoe (Crassostrea ariakensis) and Pacific (C. gigas) oysters from a natural oyster reef in Laizhou Bay, China were compared with shell height at age estimates from triploid C. ariakensis of known age from the Rappahannock River, Virginia. C. ariakensis and C. gigas reach shell heights in excess of 76 mm (3 inches) within 2 years after settlement regardless of the source location. This fast growth appears to continue through at least we 4 or age 5 in wild individuals, because the growth trajectories for both specie, had not reached asymptotic height in (he oldest …
Fish Assemblages Found In Tidal-Creek And Seagrass Habitats In The Suwannee River Estuary, Troy D. Tuckey, Mark Dehaven
Fish Assemblages Found In Tidal-Creek And Seagrass Habitats In The Suwannee River Estuary, Troy D. Tuckey, Mark Dehaven
VIMS Articles
Fish assemblages were investigated in tidal-creek and seagrass habitats in the Suwannee River estuary, Florida. A total of 91,571 fish representing 43 families were collected in monthly seine samples from January 1997 to December 1999. Tidal creeks supported greater densities of fish (3.89 fish/m(2); 83% of total) than did seagrass habitats (0.93 fish/m(2)). We identified three distinct fish assemblages in each habitat: winter-spring, summer, and fall. Pinfish (Lagodon rhomboides), pigfish (Orthopristis chrysoptera), and syngnathids characterized seagrass assemblages, whereas spot (Leiostomus xanthurus), bay anchovy (Anchoa mitchilli), silversides (Menidia spp.), mojarras (Eucinostomus spp.), and fundulids characterized tidal-creek habitats. Important recreational and commercial …
Standard And Routine Metabolic Rates Of Juvenile Sandbar Sharks (Carcharhinus Plumbeus), Including The Effects Of Body Mass And Acute Temperature Change, W Wesley Dowd, Richard Brill, Peter Bushnell, John A. Musick
Standard And Routine Metabolic Rates Of Juvenile Sandbar Sharks (Carcharhinus Plumbeus), Including The Effects Of Body Mass And Acute Temperature Change, W Wesley Dowd, Richard Brill, Peter Bushnell, John A. Musick
VIMS Articles
Standard and routine metabolic rates (SMRs and RMRs, respectively) of juvenile sandbar sharks (Carcharhinus plumbeus) were measured over a range of body sizes (n=34) and temperatures normally associated with western Atlantic coastal nursery areas. The mean SMR Q(10) (increase in metabolic rate with temperature) was 2.9 +/- 0.2. Heart rate decreased with increasing body mass but increased with temperature at a Q(10) of 1.8-2.2. Self-paired measures of SMR and RMR were obtained for 15 individuals. Routine metabolic rate averaged 1.8 +/- 0.1 times the SMR and was not correlated with body mass. Assuming the maximum metabolic rate of sandbar sharks …
Survival Of White Marlin (Tetrapturus Albidus) Released From Commercial Pelagic Longline Gear In The Western North Atlantic, David Kerstetter, John E. Graves
Survival Of White Marlin (Tetrapturus Albidus) Released From Commercial Pelagic Longline Gear In The Western North Atlantic, David Kerstetter, John E. Graves
VIMS Articles
To estimate postrelease survival of white marlin (Tetrapturus albidus) caught incidentally in regular commercial pelagic longline fishing operations targeting swordfish and tunas, short-duration popup satellite archival tags (PSATs) were deployed on captured animals for periods of 5-43 days. Twenty (71.4%) of 28 tags transmitted data at the preprogrammed time, including one tag that separated from the fish shortly after release and was omitted from subsequent analyses. Transmitted data from 17 of 19 tags were consistent with survival of those animals for the duration of the tag deployment. Postrelease survival estimates ranged from 63.0% (assuming all nontransmitting tags were evidence of …
Growth And Maturity Of Salmon Sharks (Lamna Ditropis) In The Eastern And Western North Pacific, And Comments On Back-Calculation Methods, Kenneth J. Goldman, John A. Musick
Growth And Maturity Of Salmon Sharks (Lamna Ditropis) In The Eastern And Western North Pacific, And Comments On Back-Calculation Methods, Kenneth J. Goldman, John A. Musick
VIMS Articles
Age and growth estimates for salmon sharks (Lamna ditropis) in the eastern North Pacific were derived from 182 vertebral centra collected from sharks ranging in length from 62.2 to 213.4 cm precaudal length (PCL) and compared to previously published age and growth data for salmon sharks in the western North Pacific. Eastern North Pacific female and male salmon sharks were aged up to 20 and 17 years, respectively. Relative marginal increment (RMI) analysis showed that postnatal rings form annually between January and March. Von Bertalanffy growth parameters derived from vertebral length-at-age data are L-proportional to=207.4 cm PCL, k=0.17/yr, and t(0)=-2.3 …
Influence Of Shallow-Water Habitats And Shoreline Development On Abundance, Biomass, And Diversity Of Benthic Prey And Predators In Chesapeake Bay, Rochelle D. Seitz, Rom Lipcius, N. H. Olmstead, M. S. Seebo
Influence Of Shallow-Water Habitats And Shoreline Development On Abundance, Biomass, And Diversity Of Benthic Prey And Predators In Chesapeake Bay, Rochelle D. Seitz, Rom Lipcius, N. H. Olmstead, M. S. Seebo
VIMS Articles
Within the coastal zone, waterfront development has caused severe loss of shallow-water habitats, such as salt marshes and seagrass beds. Although the effects of habitat degradation on community structure within intertidal marshes have been well studied, little is known about the impact of habitat degradation on, and the ecological value of, subtidal shallow-water habitats, despite the prevalence of these habitats in coastal ecosystems. In coastal habitats, bivalves are dominant benthic organisms that can comprise over 50% of benthic prey biomass and are indicative of benthic production. We quantified bivalve diversity, density, and biomass in deep and shallow (< 1.5 m MLW) unstructured subtidal habitats in 2 tributaries of lower Chesapeake Bay (Elizabeth-Lafayette River system and York River). We also examined the effects of shoreline alteration in shallow habitats by contrasting the benthos of the subtidal areas adjacent to natural marsh, bulkhead, and rip-rap shorelines. Bivalve diversity, density, and biomass were significantly higher in shallow than in deep benthic habitats in both systems. Benthic abundance and diversity were higher in subtidal habitats adjacent to natural marsh than those adjacent to bulkhead shorelines; abundance and diversity were intermediate in rip-rap shorelines, and appeared to depend on landscape features. Predator density and diversity tended to be highest adjacent to natural marsh shorelines, and density of crabs was significantly higher in natural marsh than in bulkhead habitats. There is thus a crucial link between natural marshes, infaunal prey in subtidal habitats, and predator abundance. Consequently, the indirect effects of coastal habitat degradation upon secondary production in the shallow, subtidal habitats adjacent to salt marshes may be as great as or greater than direct habitat effects.
Assessing Effectiveness Of The Blue Crab Spawning Stock Sanctuary In Chesapeake Bay Using Tag-Return Methodology, Debra M. Lambert, Rom Lipcius, John M. Hoenig
Assessing Effectiveness Of The Blue Crab Spawning Stock Sanctuary In Chesapeake Bay Using Tag-Return Methodology, Debra M. Lambert, Rom Lipcius, John M. Hoenig
VIMS Articles
The blue crab spawning stock in Chesapeake Bay sustained a severe and persistent decline beginning in 1992. As part of the effort to enhance the spawning stock, the spawning sanctuary in lower Chesapeake Bay was enlarged to over 240 000 ha. This marine reserve and corridor prohibits exploitation of mature females en route to or in the spawning grounds during the summer spawning season (1 June to 15 September). To assess the effectiveness of the sanctuary, we tagged terminally melted, mature females inside and outside the sanctuary during 3 sanctuary seasons (2002 to 2004). Crabs were captured throughout the bay …
Occurrence Of Imposex And Seasonal Patterns Of Gametogenesis In The Invading Veined Rapa Whelk Rapana Venosa From Chesapeake Bay, Usa, Roger L. Mann, Juliana M. Harding, Erica Westcott
Occurrence Of Imposex And Seasonal Patterns Of Gametogenesis In The Invading Veined Rapa Whelk Rapana Venosa From Chesapeake Bay, Usa, Roger L. Mann, Juliana M. Harding, Erica Westcott
VIMS Articles
The prevalence and intensity of imposex and observations on the seasonal gametogenic cycle are reported for the Asian veined rapa whelk Rapana venosa (Valenciennes, 1846), an invader of the Chesapeake Bay on the North American Atlantic coast. Adult whelks from opportunistic collections by commercial fishermen demonstrated inactivity from mid-November through early March, copulation from February through mid-November, and egg-laying activity from late May through August. All imposex females examined did not have a functional vas deferens (below Stage 3 on the vas deferens scale of Gibbs et al. 1987; J Mar Biol Assoc UK 67:507-523) and were expected to function …
Estimating Consumption Rates Of Juvenile Sandbar Sharks (Carcharhinus Plumbeus) In Chesapeake Bay, Virginia, Using A Bioenergetics Model, W Wesley Dowd, Richard Brill, Peter Bushnell, John A. Musick
Estimating Consumption Rates Of Juvenile Sandbar Sharks (Carcharhinus Plumbeus) In Chesapeake Bay, Virginia, Using A Bioenergetics Model, W Wesley Dowd, Richard Brill, Peter Bushnell, John A. Musick
VIMS Articles
Using a bioenergetics model, we estimated daily ration and seasonal prey consumption rates for six age classes of juvenile sandbar sharks (Carcharhinus plumbeus) in the lower Chesapeake Bay summer nursery area. The model, incorporating habitat and species-specific data on growth rates, metabolic rate, diet composition, water temperature (range 16.8-27.9 degrees C), and population structure, predicted mean daily rations between 2.17 +/- 0.03 (age-0) and 1.30 +/- 0.02 (age-5) % body mass/day. These daily rations are higher than earlier predictions for sandbar sharks but are comparable to those for ecologically similar shark species. The total nursery population of sandbar sharks was …