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Computation Of Oyster Yields In Virginia, J. L. Mchugh, J. D. Andrews

VIMS Articles

Drs. Andrews and Hewatt have been holding oysters in trays suspended from the Virginia Fisheries Laboratory pier at Gloucester Point, Virginia, for the past four years. The preliminary objective has been to study mortality rates, but other information has been gathered from time to time, particularly on the growth rate. During the course of these investigations we have been impressed by the yields that have been obtained, for it has not been uncommon to realize three bushels of market-sized oysters for each original bushel of seed placed in the trays.

Reduced to the simplest terms, the yield of market oysters …

Trapping Oyster Drills In Virginia Ii. The Time Factor In Relation To The Catch Per Trap, J. L. Mchugh

VIMS Articles

In using traps to remove drills from oyster ground, assuming that trapping is an effective method of reducing the activities of these pests, it is important to keep costs at a minimum. One way of reducing the cost of trapping is to increase the time interval between lifts, but if the efficiency of traps varies with time, the nature of this relationship should be considered in choosing the optimum fishing interval.

The influence of time on the catch must also be known to determine the significance of the catch per trap in drill trapping experiments. Dr. Andrews, in the first …

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 …

Temperature Control Experiments On The Fungus Disease, Dermocystidium Marinum, Of Oysters, Willlis G. Hewatt, Jay D. Andrews

VIMS Articles

In 1950 Mackin, Owen, and Collier described a fungus parasite, Dermocystidium marinim, found in oysters of Louisiana coastal waters. Since that, time numerous studies have been conducted on the nature of the fungus and its effects upon the host. It has been definitely established that the pathogen is the main contributor to the causes of mortality of oysters in some areas. Ray and Chandler (1955) have adequately reviewed the literature on the subject.

Among the various observations that have been made on the fungus disease there is very positive evidence that the incidence and intensity of the infection are primarily …

The Pound-Net Fishery In Virginia. Part 1. History, Gear Description And Catch, George K. Reid Jr.

VIMS Articles

The pound net is one of the most important fishing gears in Virginia. Recent declines in the catch of certain economically- important species have pointed to the need for study of the fishes and the fishery and its methods. The General Assembly of Virginia has requested that the Virginia Fisheries Laboratory conduct experiments to determine the proper size mesh for nets in fixed fishing devices.

A preliminary study of the pound net, embodying historical development, construction and methods of operating, and the catch trends from 1930 through 1951, was undertaken during the summer of 1953.

Although the introduction of the …