Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Life Sciences
Effects Of The June 1995 Freshet On The Main Virginia Tributaries To The Chesapeake Bay, Herbert M. Austin, Christopher F. Bonzek
Effects Of The June 1995 Freshet On The Main Virginia Tributaries To The Chesapeake Bay, Herbert M. Austin, Christopher F. Bonzek
VIMS Articles
Environmental conditions in the Virginian waters of the Chesapeake Bay area during the summerof 1995 have been characterized as a severe drought. This drought was punctuated on 27 June with a headwater (James and Rappahannock River) rain storm that produced a "freshet". Although it did not rain in the Tidewater area of Virginia, surface salinities were depressed by the run-off, and main-stem bottom ox}'gen levels dropped to z.ero in the James and Rappahannock rivers. The effects of the reduced oxygen were apparent on the James River oyster stock, particularly the reduction in spatfall, and to a lesser degree on the …
A Retrospective Time Series Analysis Of Oyster, Crassostrea Virginica, Recruitment (1946-1993), Herbert Austin, David Evans, Dexter Haven
A Retrospective Time Series Analysis Of Oyster, Crassostrea Virginica, Recruitment (1946-1993), Herbert Austin, David Evans, Dexter Haven
VIMS Articles
Temporal patterns of eastern oyster, Crassostrea virginica (Gmelin 1791), spatfall in the Virginia tributary rivers to the Chesapeake Bay showed a decline in all rivers from 1946 through the early 1970s, with a subsequent leveling off. The decline was most severe in the James and less so moving north to the York and Rappahannock Rivers; it was least severe in the Potomac River. Yearling patterns generally mirrored the spat. Cluster analyses grouped the bars naturally by up- and downriver spatfall patterns. They also clustered this way when between-river comparisons were made. Spatfall showed a significant cross-correlation with yearlings a year …
Demographic Analysis Of The Sandbar Shark, Carcharhinus Plumbeus In The Western North Atlantic, Tr Sminkey, Ja Musick
Demographic Analysis Of The Sandbar Shark, Carcharhinus Plumbeus In The Western North Atlantic, Tr Sminkey, Ja Musick
VIMS Articles
The sandbar shark, Carcharhinus plumbeus, is the most common large coastal shark in Virginia waters and is an important component of recreational and commercial fisheries along the east coast of the United States. Sandbar shark demographic analyses, using known and estimated life history parameters, including fishing mortality (F) at ages and levels estimated in a recent stock assessment, were used to estimate potential population growth and exploitation. Life history tables were constructed by using best estimates of natural mortality (M) of O.11 or 0.07 for maximum ages of 30 or 60 yr, respectively. Natality was fixed at 2.1 female pups/yr. …
Mitochondrial Dna Diversity And Divergence Among Sharpnose Sharks, Rhizoprionodon Terraenovae, From The Gulf Of Mexico And Mid-Atlantic Bight, Edward J. Heist, John Musick, John Graves
Mitochondrial Dna Diversity And Divergence Among Sharpnose Sharks, Rhizoprionodon Terraenovae, From The Gulf Of Mexico And Mid-Atlantic Bight, Edward J. Heist, John Musick, John Graves
VIMS Articles
The Atlantic sharpnose shark, Rhizoprionodon terraenovae, is a small coastal shark that is harvested in both directed and nondirected fisheries throughout its range. Because pups of this species are found both along the southeastern U.S. Atlantic coast and the Gulf of Mexico, it is possible that multiple isolated breeding stocks exist. Restriction fragment length polymorphism analysis of mitochondrial DNA was used to test the hypothesis that Atlantic sharpnose sharks from the U.S. Atlantic coast and the western Gulf of Mexico have identical mitochondrial haplotype frequencies and therefore no apparent genetic stock structure. Seven mitochondrial haplotypes were detected among 52 individuals. …