Digital Commons Network^™

Spatiotemporal Modeling Of Nursery Habitat Using Bayesian Inference: Environmental Drivers Of Juvenile Blue Crab Abundance, A. Challen Hyman, Grace S. Chiu, Mary C. Fabrizio, Rom Lipcius

VIMS Articles

Nursery grounds provide conditions favorable for growth and survival of juvenile fish and crustaceans through abundant food resources and refugia, and enhance secondary production of populations. While small-scale studies remain important tools to assess nursery value of structured habitats and environmental factors, targeted applications that unify survey data over large spatial and temporal scales are vital to generalize inference of nursery function, identify highly productive regions, and inform management strategies. Using 21 years of spatio-temporally indexed survey data (i.e., water chemistry, turbidity, blue crab, and predator abundance) and GIS information on potential nursery habitats (i.e., seagrass, salt marsh, and unvegetated …

Bridging Disciplines To Advance Elasmobranch Conservation: Applications Of Physiological Ecology, K Lyons, Js Bigman, Et Al, Kevin C. Weng, Et Al, Richard Brill, Cn Bedore

VIMS Articles

A strength of physiological ecology is its incorporation of aspects of both species' ecology and physiology; this holistic approach is needed to address current and future anthropogenic stressors affecting elasmobranch fishes that range from overexploitation to the effects of climate change. For example, physiology is one of several key determinants of an organism's ecological niche (along with evolutionary constraints and ecological interactions). The fundamental role of physiology in niche determination led to the development of the field of physiological ecology. This approach considers physiological mechanisms in the context of the environment to understand mechanistic variations that beget ecological trends. Physiological …

Reef Height Drives Threshold Dynamics Of Restored Oyster Reefs, Allison M. Colden, Robert J. Latour, Rom Lipcius

VIMS Articles

Nonlinear threshold responses to biotic or abiotic forcing may produce multiple population trajectories dependent upon initial conditions, which can reinforce population recovery or drive local ex - tinction, yet experimental tests of this phenomenon are lacking in marine ecosystems. In field experiments at 4 sites in 2 tributaries of lower Chesapeake Bay, we examined demographic responses (density and survival) of eastern oyster Crassostrea virginica populations to reef height and associated gradients in sediment deposition and habitat complexity. After 2 yr, oyster reefs exhibited diverging trajectories to ward either degradation or persistence, dependent upon initial reef height. Reefs higher than 0.3 …

Evidence Of Eelgrass (Zostera Marina) Seed Dispersal By Northern Diamondback Terrapin (Malaclemys Terrapin Terrapin) In Lower Chesapeake Bay, Diane C. Tulipani, Romuald N. Lipcius

VIMS Articles

The initial discovery in May 2009 of eelgrass (Zostera marina) seeds in fecal samples of wild-caught northern diamondback terrapins (Malaclemys terrapin terrapin) was the first field evidence of eelgrass seed ingestion in this species. This finding suggested the potential of terrapins as seed dispersers in eelgrass beds, which we sampled for two additional years (2010 and 2011). Seeds were only found in feces of terrapins captured prior to June 8 in all three years, coinciding with eelgrass seed maturation and release. Numbers of seeds in terrapin feces varied annually and decreased greatly in 2011 after an eelgrass die off in …

Migratory And Within-Estuary Behaviors Of Adult Summer Flounder (Paralichthys Dentatus) In A Lagoon System Of The Southern Mid-Atlantic Bight, Karen M. Capossela, Mary C. Fabrizio, Richard Brill

VIMS Articles

We monitored the movements of 45 adult Summer Flounder (Paralichthys dentatus) between June 2007 and July 2008 through the use of passive acoustic telemetry to elucidate migratory and within-estuary behaviors in a lagoon system of the southern mid-Atlantic Bight. Between 8 June and 10 October 2007, fish resided primarily in the deeper (>3 m) regions of the system and exhibited low levels of large-scale (100s of meters) activity. Mean residence time within this estuarine lagoon system was conservatively estimated to be 130 days (range: 18-223 days), which is 1.5 times longer than the residence time previously reported for Summer …

Patterns And Drivers Of The Demersal Fish Community Of Chesapeake Bay, Andre Buchheister, Christopher F. Bonzek, James Gartland, Robert J. Latour

VIMS Articles

Large-scale research on the environmental, biological, and anthropogenic drivers of fish distributions, abundances, and community structure can identify patterns and trends within systems, provide mechanistic insight into ecosystem functioning, and contribute to ecosystembased fisheries management. This study synthesized 10 yr of extensive fisheries-independent bottom trawl data (2002 to 2011) to evaluate drivers of demersal fish community structure in Chesapeake Bay, the largest estuary in the United States. Changes in community composition were assessed using constrained correspondence analysis. Also, aggregate community metrics (species richness, Simpson diversity, and catch-per-unit-effort [CPUE] of species groups) were modeled using generalized additive models. Five species (Atlantic …

First Records Of Hypleurochilus Geminatus And Centropristis Philadelphica From Chesapeake Bay, Aimee D. Halvorson

VIMS Articles

During the fall of 2007, Centropristis philadelphica (rock seabass) and Hypleurochilus geminatus (crested blenny) were collected from Chesapeake Bay. These captures are significant as they represent the first substantiated record of C. philadelphica from Chesapeake Bay and only the second and third validated records of H. geminatus. Additionally, the first record of H. geminatus from Chesapeake Bay was only recently recognized since the specimen had been previously misidentified as Parablennius marmoreus (seaweed blenny). The collection of seven individuals of H. geminatus in 2007, from two locations, indicates that the species may be resident within the Chesapeake Bay estuary.

Activity In The Pallial Nerve Of Knobbed (Busycon Carica) And Channeled (Busycotypus Canaliculatum) Whelks Recorded During Exposure Of The Osphradiurn To Odorant Solutions, Christopher Magel, Kristin Wakefield, Nancy Targett, Richard Brill

VIMS Articles

Adult horseshoe crabs (Limulus polyphemus) are the preferred bait in the U.S. east coast whelk pot fishery, but their harvest is being restricted because of severe population declines in the Chesapeake and Delaware bays. To identify other baits, the activity in the pallial nerve of whelks was determined during exposure of the osphradium to odorant solutions prepared from horseshoe crab eggs, horseshoe crab hemolymph, and hard clam (Mercenaria mercenaria) tissue. All three elicited significant responses; bait based on them may provide an alternative to the use of adult horseshoe crabs, although extensive behavioral testing remains to be done. Channeled whelk …

Diet Composition Of Large Striped Bass (Morone Saxatilis) In Chesapeake Bay, John F. Walter, Hebert M. Austin

VIMS Articles

Large (>458 mm) striped bass (Morone saxatilis) are dominant predators in Chesapeake Bay. In recent years, the Chesapeake Bay stock of striped bass has increased dramatically, raising concerns about their predatory impact and their forage requirements. In response to these concerns and the need for more recent ecological studies, this investigation Was conducted to characterize feeding habits of large striped bass in Chesapeake Bay. Stomach contents from 1225 striped bass from 458 to 1151 mm TL were examined in the spring and fall of 1997 and 1998. Striped bass consumed 52 different species of vertebrates and invertebrates; however, only …

Feeding Habits Of Young-Of-Year Striped Bass Morone Saxatilis, And White Perch, Morone American In Lower James River, Va, Paul J. Rudershausen, Joseph G. Loesch

VIMS Articles

A total of 188 young-of-year (YOY) striped bass, Marone saxatilis, and 199 YOY white perch, Marone americana, were collected by pushnet, seine and trawl during 24-hour periods from June through August, 1992 in lower James River, Virginia. The purpose was to identify prey and temporal and spatial feeding habits. Copepods were the most numerous prey of both species. Fishes and mysids comprised the largest volumetnc percentage of diets of striped bass and white perch, respectively. Using an index of relative importance, leptodorids and copepods were the most important prey of striped bass and white perch, respectively. Botl1 species shifted from …

Estimates Of Naked Goby (Gobiosoma Bosc), Striped Blenny (Chasmodes Bosquianus) And Eastern Oyster (Crassostrea Virginica) Larval Production Around A Restored Chesapeake Bay Oyster Reef, Jm Harding, Roger L. Mann

VIMS Articles

Naked gobies (Gobiosoma bose) and striped blennies (Chasmodes bosquianus) rely on oyster reefs for nesting sites, feeding grounds, and refugia from predation by upper level piscivores. Seasonal densities of Eastern oysters (Crassostrea virginica), naked gobies, and striped blennies on Palace Bar Reef, Piankatank River, Virginia were quantified and used to develop species-specific larval production estimates. Densities of oyster adults, juveniles, and articulated shell valves (the result of recent mortality) did not significantly change from November 1995 to November 1996. Naked goby and striped blenny densities varied with substrate type and season; peak fish densities for both species were observed in …

Settlement Of Blue Crab Postlarvae In Western North Atlantic Estuaries, J Van Montfrans, Ce Epifano, Dm Knott, R M. Lipcius, Et Al

VIMS Articles

We quantified variability in daily settlement of blue crab postlarvae (megalopae) on identical artificial settlement substrates at up to 6 sites concurrently over a broad geographic expanse (similar to 1300 km) of the western North Atlantic (Delaware-South Carolina, USA). The 4-year study encompassed the blue crab recruitment season (generally July-November) from 1989-1992. Regional settlement was characterized by: (1) constant low levels of daily settlement punctuated by significantly non-random, episodic peaks of variable duration and intensity with peaks collectively accounting for at least half the total annual settlement at a site; (2) spatial and temporal variability leading to a general lack …

Settlement Indices For Blue Crab Megalopae In The York River, Virginia: Temporal Relationships And Statistical Efficiency, Ks Metcalfe, J Van Montfrans, Rom Lipcius

VIMS Articles

The efficacy of artificial settlement substrates in quantifying relative rates of settlement of blue crab, Callinectes sapidus, postlarvae (megalopae) was examined. The technique has been widely used to assess settlement at local (Chesapeake Bay) and broad geographic scales (Atlantic and Gulf Coasts). This analysis examined differences in settlement between two configurations of substrates and two depths of deployment, in relation to lunar day, month, year and hours of flood tide occurring at night. Substrates were deployed daily for four years (1989-1992) during the settlement season (July-November) in the York River, Virginia. Settlement did not differ between substrate configurations (flat and …

Variation In Planktonic Availability And Settlement Of Blue-Crab Megalopae In The York River, Virginia, Ej Olmi, J Van Montfrans, Rn Lipcius, R J. Orth, Pw Sadler

VIMS Articles

Blue crab, Callinectes sapidus, megalopae and juveniles were sampled in the plankton and on natural (grassbeds) and artificial settlement substrates (collectors) at two sites in each of two areas of a lower Chesapeake Bay tributary (York River, Virginia) to examine spatial variability in blue crab recruitment. Spatial patterns of abundance were not consistent across habitats (plankton, artificial collectors and grassbeds) or time. Densities of planktonic megalopae were homogeneous at 1-2 m (within site) but varied at spatial scales of hundreds of meters (between sites) and kilometers (between areas). Settled megalopae were distributed unevenly within and between sites, but their abundance …

Community And Trophic Organization Of Nekton Utilizing Shallow Marsh Habitats, York River, Virginia, Stephen M. Smith, James G. Hoff, Steven P. O'Neil, Michael P. Weinstein

VIMS Articles

No abstract provided.

Morphology And Development Of Hatchery-Cultured American Shad, Alosa-Sapidissima (Wilson), James R. Johnson, Joseph G. Loesch

VIMS Articles

No abstract provided.

Aspects Of Reproductive-Biology Of Weakfish, Cynoscion-Regalis (Sciaenidae), In North-Carolina, John Merriner

VIMS Articles

No abstract provided.

Oyster Mortality Studies In Virginia. Ii. The Fungus Disease Caused By Dermocystidium Marinum In Oysters Of Chesapeake Bay, Jay D. Andrews, Willis G. Hewatt

VIMS Articles

A high death rate of oysters in Virginia waters during the warm months of summer and fall was reported by Hewatt & Andrews (1954b). One of the most important causes of this warm-season mortality is the fungus Dermocystidium marinum, a pathogen discovered in the Gulf of Mexico by Mackin, Owen & Collier (1950). The fungus is found along the coast of the Western Atlantic from Delaware Bay to Florida and on the coast of the Gulf of Mexico from Florida to Texas.

In Chesapeake Bay the disease was studied for pathogenicity to oysters, seasonal occurrence, distribution, and its effect on …

Trapping Oyster Drills In Virginia Iii. The Catch Per Trap In Relation To Condition Of Bait, J. L. Mchugh

VIMS Articles

In the course of trapping experiments previously described (Andrews 1955, McHugh 1955), a question arose concerning deterioration of bait with time. It is fairly obvious to those who fish the traps that the condition of the bait changes. The smallest oysters die first, through predation by drills, crabs, and other enemies, and through smothering in the muddy bottom. Barnacles and other organisms on the shells also die from various causes. The valves of the dead oysters soon separate, and some are lost through meshes of the trap, so that the volume of bait also decreases. Stauber (1943) found that efficiency …

Trapping Oyster Drills In Virginia I. The Effect Of Migration And Other Factors On The Catch, Jay D. Andrews

VIMS Articles

Virginia oystermen have tried trapping of drills as a control measure and discarded it as ineffective and too costly. It is true that their efforts were sporadic and lacking in persistence, and the effects of their trapping were not adequately appraised. They expected returns in the form of increased yields too quickly. Nevertheless, these brief trials have convinced even the most progressive oystermen that trapping· drills is not the answer to their predation problem. In Chesapeake Bay, consequently, no conscious effort is made to control drills. Oyster grounds are often allowed to lie fallow for several year's, a practice which …