Physiological response of scup, stenotomus chrysops, to a simulated trawl capture and escape event

Scup (Stenotomus chrysops) were severely exercised by manual chasing for 6 min, and the clearance of lactate over a 12 hr period was evaluated. Lactate peaked from 0.5 to 1.0 hr following exercise with concentrations ranging from 61.0 to 126.0 mg/dL and returned to rested concentrations within 4 hr post-exercise. Concentrations of lactate in rested fish ranged from 5.2 to approximately 23.0 mg/dL. Fish were observed for 10 days following exercise for delayed mortality. A 100% survival of scup was observed with no significant difference between control and experimental populations. Swimming performance was evaluated for 14.0 to 15.0 cm fork length scup, with a towed stimulus through a still-water circular swimming channel, at prolonged and burst speeds. A maximum sustainable swimming speed of 2.2 BL/sec was observed. Between the speeds of 3.0 and 3.3 BL/sec and 4.4 BL/sec, endurance time significantly decreased with the increase in swimming speed. Blood lactate concentrations were measured at 0.5 and 4.0 hr post exercise, and were used as an indicator of white muscle recruitment. A significant difference was not found between rested and experimental mean lactate concentrations at the maximum sustainable swimming speed of 2.2 BL/sec. White muscle recruitment indicated by increases in lactic acid, was recorded at speeds above the maximum sustained swimming speed, and mean blood lactate concentrations were significantly different within blood sampling times and between swimming speeds. Based on the results of our investigations of lactate recovery in scup following a simulated trawl capture and escape event, we believe that scup interacting with a bottom trawl and subsequently escaping, are physiologically stressed by the event, but recover in less than 6 hr. All experimentally treated fish survived both exhaustive exercise and prolonged swimming, suggesting encounter mortality is minimal. The results of this study do not address the effects of possible physical damage on escape or the effect of multiple encounters

Bacterial Community Profiling of the Eastern Oyster (\u3cem\u3eCrassostrea virginica\u3c/em\u3e): Comparison of Culture-Dependent and Culture-Independent Outcomes

Tissue-associated bacterial community profiles generated using a nested polymerase chain reaction–denaturing gradient gel electrophoresis (DGGE) approach and culture-dependent and culture-independent isolation techniques were compared. Oyster samples were collected from 2 harvest areas along the coast of Maine, in the United States. Profiles from both isolation strategies were evaluated using Sorensen’s index of similarity and cluster analysis of gel banding patterns. Culture independent profiles were further evaluated using the Shannon diversity index. In general, the culture-dependent strategy resulted in a greater number of bands within a profile. Bacterial DGGE profiles were found to be highly similar within an isolation strategy, with a higher degree of unrelatedness between culture-dependent and -independent techniques. Cluster analysis identified bands present in the culture-dependent strategy and not the total DNA technique, and vice versa. Significant differences in community profiles between oyster-associated and seawater were observed, indicating a diverse group of specialist bacterial species inhabit and are able to proliferate within the oyster

Training in Reversal: A Fishing Gear Workshop by Fishermen for Non-Fishermen

Increasingly, people without fishing gear backgrounds are involved in fisheries management. While they have strengths in their respective professions, an operational knowledge of fishing gears is lacking. Such gaps can be filled with collaborative learning workshops utilizing industry members as instructors. This reversal training strategy also builds mutual understanding between groups that are usually at odds. Commercial trawlers and gillnetters owned and operated by the industry were used as at-sea workshop platforms for two 3-day workshops. Participants included National Marine Fisheries Service employees, Congressional and Senatorial staffers, State fisheries scientists, Marine Docents, extension professionals, and cooperative research funding organizations