Microbial content was characterized and levels of three amines (histamine, cadaverine, and putrescine) were determined in Spanish mackerel (Scomberomorus macuZutus) decomposed at PC, WC, and 30°C for varying lengths of time. Correlations were shown (1) between the levels of the histamine, cadaverine, and putrescine and the time and temperature of decomposition, (2) between the ratios of cadaverine/histamine and putrescine/histamine levels and the temperature of decomposition, and (3) behveen increasing total microbial counts and rising amine levels. A total of 14 bacterial species with histidine decarboxylase activity were isolated from decomposing fish, including three species (Acinetobacter lwofi, Pseudomonas putrefaciens, and Aeromonas hydrophila)not previously reported to have the potential to produce histamine.

The numbers of fecal coliforms and enteroviruses present in oysters and/or their growing waters of two Mississippi reefs were determined over a 12-month period. Bacterial and viral levels reflected the classification of the waters at each location as set by the Mississippi State Board of Health in compliance with the National Shellfish Sanitation Program, but statistically significant correlations between these levels were not observed. Twelve viral isolates were found at an approved oyster harvesting location, eight of which were identified as poliovirus type 1. At the prohibited site, 146 viruses were isolated including poliovirus types 1 and 2, echovirus type 24 and several isolates which remain to be identified. The number of virus isolates from samples from each location represented approximately 35% of the number of plaques observed; however, no consistent ratio of plaque to confirmed virus was demonstrated. The results suggest that the fecal coliform levels in oyster growing waters do not reflect the level of virus contaminaton in either approved or prohibited waters.

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The levels of 19 constituents of penaeid shrimp hemolymph were analytically determined. Ionic components of hemolymph were influenced by water salinity but not by water pH or temperature. Levels of hemolymph metabolites varied from sample to sample; the differences were possibly generated by variations in diet and stress. Enzymatic measurements were reported for possible comparison with future studies on stress, health, or immune status of cultured penaeid popula-

Marine mammals respond to the presence of polycyclic and planar halogenated aromatic hydrocarbons (PAH or PHAH) with the induced expression in endothelium of cytochrome P4501A1, regulated through the aryl hydrocarbon receptor (AHR) transcription factor. Physiological responses in other animals, such as edema and inflammation indicate that the endothelium may be compromised by exposure to AHR agonists, which are ubiquitous in the marine environment. In other mammals and fish the cellular and molecular consequences of exposure to AHR agonists have been elucidated in cultured endothelial cells. We have cultured and characterized cetacean endothelial cells (EC) and used them in induction studies. Endothelial cells were cultured from the lung and kidney of the bottlenose dolphin Tursiops truncatus and exposed to the AHR agonists β-naphthoflavone (βNF) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). βNF (1-3 µM) induced significant increases in CYP1A1(O-deethylation of 7-ethoxyresorufin to resorufin;EROD) activity to 3.6 and 0.92 pmol/mg/min in lung and kidney EC, respectively. TCDD was more potent than βNF, and more efficacious, with maximum induction of CYP1A1activity of 10.1 and 15.2 pmol/mg/min in lung and kidney EC at 3-10 nM TCDD. The differential response indicates that the lung and kidney endothelial cells in culture retain the ability to respond in a selective manner to specific stimuli. Both the molecular mechanisms of induction and the physiological consequences, especially in the vasculature, of toxicant exposure can be studied in this system.