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Seasonal differences in plasma cortisol and gill corticosteroid receptors in upper and lower mode juvenile Atlantic salmon Seasonal differences in plasma cortisol and gill corticosteroid receptors in upper and lower mode juvenile Atlantic salmon

Circulating plasma cortisol and gill corticosteroid receptors (CR) have been observed to change seasonally in conjunction with smolting in Atlantic salmon. To differentiate whether these changes are seasonal or ontogenic, juvenile Atlantic salmon parr were separated by size into upper (UM) and lower mode (LM) in September. At monthly intervals, the fish were sampled for plasma cortisol...
Authors
J. Mark Shrimpton, Stephen D. McCormick

Atlantic salmon smolts are more responsive to an acute handling and confinement stress than parr Atlantic salmon smolts are more responsive to an acute handling and confinement stress than parr

Atlantic salmon parr and smolts reared under a natural temperature and photoperiod regime were subjected to an acute handling and confinement stress in early May. Smolts had a mean plasma cortisol concentration of 10 ng/ml before stress and 242 ng/ml 3 h after initiation of stress which returned to pre-stress levels within 8 h. Parr had a plasma cortisol concentration of 4 ng/ml prior to...
Authors
J. B. Carey, Stephen D. McCormick

Repeated acute stress reduces growth rate of Atlantic salmon parr and alters plasma levels of growth hormone, insulin-like growth factor I and cortisol Repeated acute stress reduces growth rate of Atlantic salmon parr and alters plasma levels of growth hormone, insulin-like growth factor I and cortisol

Atlantic salmon (Salmo salar) parr were subjected to acute handling stresses and growth-monitored for at least 30 days. In fish stressed twice daily, growth rate in weight was 61% lower than controls after 11 days (1.00 vs. 2.57% day−1) and over a 30 day period it was 50% lower than controls (1.53 vs. 3.07% day−1). In fish stressed once daily, growth rate was 18% lower than controls...
Authors
S. D. McCormick, J. M. Shrimpton, J. B. Carey, M. F. O’Dea, K. E. Sloan, S. Moriyama, Bjorn Thrandur Bjornsson

Epizootics of cancer in fish associated with genotoxins sediment and water Epizootics of cancer in fish associated with genotoxins sediment and water

Neoplasm epizootics in fish from a wide variety of freshwater, marine, and estuarine locations have been associated with genotoxins in sediment or water. The majority of cases have involved benthic or bottom feeding fish living in habitats with sediment contaminated by PAHs. The most common lesions involved in such epizootics include liver neoplasms, both biliary and hepatic, and skin...
Authors
P. C. Baumann

Relation of lead exposure to sediment ingestion in mute swans on the Chesapeake Bay, USA Relation of lead exposure to sediment ingestion in mute swans on the Chesapeake Bay, USA

Although wildlife risk assessments are generally based on the accumulation of environmental contaminants through food chains, wildlife may also ingest contaminants incidentally with sediment. Forty-two mute swans (Cygnus olor) were collected from unpolluted portions of central Chesapeake Bay, Maryland, USA, in spring 1995, and their intestinal digesta were analyzed for 13 metals...
Authors
W. N. Beyer, D. Day, Alexandra Morton, Y. Pachepsky

Environmental impacts on the southern Florida coastal waters: A history of change in Florida Bay Environmental impacts on the southern Florida coastal waters: A history of change in Florida Bay

Analyses of four cores located in the northern transitional, eastern, and central portions of Florida Bay reveal historical patterns of change in salinity and seagrass distribution. Salinity and the distribution of seagrass beds are two critical issues for the restoration of Florida Bay. The distribution of benthic fauna in Bob Allen 6A and Russell Bank 19B cores illustrates changes in
Authors
G. Lynn Wingard, S. E. Ishman, C. W. Holmes

Estimation of temporal variability of survival in animal populations Estimation of temporal variability of survival in animal populations

Temporal variation of demographic characteristics for animal populations is of interest to both ecologists and biological modelers. The standard deviation of a series of estimated parameter values (e.g., estimated population size) or some function thereof (e.g., log of the estimated parameters) is commonly used as a measure of temporal variability. These measures of temporal variation...
Authors
William R. Gould, James D. Nichols
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