Journal of the Southeastern Association of Fish and Wildlife Agencies

A continuous-flow respirometer was constructed to measure the effect of pesticides and related pollutants on oxygen consumption of estuarine fishes. The parts of the respirometer in contact with pollutants were constructed of glass and teflon for efficiency in cleaning. Filtered, irradiated sea water of constant temperature and salinity was gravity-fed through ten experimental and ten control respiration chambers in which individual fish were held. Flow rates through the chambers were controlled by stopcocks and measured by flowmeters; dissolved oxygen was determined by the Winkler method before and after water passed through each chamber. Pollutants were metered into the experimental chambers by syringe pump.

Ultrasonic transmitters were commercially purchased. They were cylindrical in shape, 90 mm long by 19 mm in diameter, and they weighed 29.5 g, with battery, in water. They transmitted at a frequency of 74 kilocycles/second. The number of days of active transmission was related to battery type and impulse rate. Transmitters emitting a greater number of impulses per second, with a range of 2.4 to 5.8, tended to stop transmitting sooner than those emitting fewer impulses per second. The difference in longevity between a 3 and 6 impulse per second transmitter was estimated to be 14 days. The average transmitting life of 11 transmitters was 30.5 days, with a range from 24 to 52 days. Battery capacity was a significant factor affecting longevity; transmitters with a 160 milliamperehour battery had an average longevity of only 18.5 days. None of the tags had a transmitting life equal to the 60 days advertised by the manufacturer.

Benthic samples were sorted by three methods: electrical stimulus applied to living organisms, preserved in rose bengal formalin solution, and preserved natural-colored. The rose bengal stained samples were picked most accurately and rapidly except in very low invertebrate concentrations where the electrical stimulus was more efficient. Naturalcolored samples had the least accurate retrieval and were picked at a rate intermediate to the other two methods.

Bold's Basal and Gorham's media were used to culture algae removed from the digestive tracts of Blue Tilapia, Tilapia aurea (Steindachner). Nine fish representing three-size categories collected from Lake Parker, Florida, were used in the study. Samples extracted from three areas of the gut were introduced to the culture media within twenty-four hours after collection. Microscopic examination of the cultured materials was conducted over a four-week period to enable the completion of reproductive cycles and excystment of algal cells. Twenty-one taxa of algae were identified by sampling the culture vessels. Planktonic green algae were the dominant foods of tilapia at the time of sampling. Species of Scenedesmus, Pediastrum, A.nkistrodesmus and chlorococcoid algae appeared in all specimens. Colonial chlorophytes, pennate diatoms, flagellated unicells, and remains of filamentous algae occurred less frequently. Spirulina sp.

We simulated thermal increases encountered by postlarval and juvenile estuarine fishes entrained in power plant cooling systems. Three methods were used to measure the effects of thermal shock on these fishes: (1) critical thermal maximum (CTM); (2) changes in routine oxygen consumption; and (3) survival after exposure to sudden increases in temperature for various periods of time. For menhaden, spot, and pinfish acclimated at 15° C, CTM values were 29.4, 31.0, and 31.0 respectively. Oxygen consumption of menhaden, spot, and pinfish, increased as we raised the temperature in 5° increments from the environmental temperature, indicating that additional energy expenditures are necessary to maintain the fish at the elevated temperatures. At temperatures of 15° C above the normal environmental temperature, all of the menhaden, spot, and pinfish died within 5 to 10 minutes.

The acute effects of four crude oils and two oil spill removers on four species of marine shrimp (Penaeus setiferus, P. aztecus, Palaemonetes vulgaris, and P. pugio) were determined. Results of 48-hour bioassays showed that distinctive differences in toxicity existed between crude oils from different areas with all shrimp tested. The oil spill removers were much more toxic than the crude oils. Addition of the oil spill removers to all crude oils at recommended application ratios increased the toxicity of both the crude oils and the oil spill removers, indicating a synergistic effect. The Palaemonetes species appeared more tolerant to all toxicants. Evidence indicates that the most serious effects of oil pollution would be noted in the shallower areas where high concentrations of toxic compounds may build up.

The movements of brown shrimp (Penaeus aztecus) and white shrimp (P. setiferus) over weirs in a South Louisiana esturary were influenced by tides. Brown shrimp concentrations inside the weir were greatest on incoming tides, water flowing into the weired area. The incoming water stimulated brown shrimp to the weir. White shrimp concentrations inside the weir depended on water head differences between weired and outside waters. The head difference usually occurred with approaching cold fronts and drops in temperature. The shrimp catch was greatest at night.

Three years ago, in June 1968, our Chief of Law Enforcement and I went to the State of Pennsylvania, to see what we could learn about their Special Investigation work. We visited with the Pennsylvania Wildlife heads for three days and were sold on the type of work or ways of apprehending large scale, illegal, killing and selling of game. They pointed out to us the most important points to consider; administration of program by experienced personnel, the selection of competent personnel for undercover agents, never use one of your agents for any type of personnel investigation. Your agents are solely to collect evidence and information of game law crimes (in most cases, impossible through routine law enforcement). We realized that we were faced with an ever increasing law enforcement problem involving large scale, illegal killing and selling of game.

In 1970 the Arkansas Game and Fish Commission initiated a Wildlife Officer Cadet School for the purpose of giving new Wildlife Officers some formal training in the operation of the Commission before assigning them to positions in the field. The School, which is a prerequisite to being hired as a Wildlife Officer, consists of five weeks of schooling at Arkansas Polytechnic College and one week of field training on the skills a Wildlife Officer must employ and the situations he will face in his daily activities. The Commission is also making an effort to have all field personnel complete the schooling at Arkansas Tech, and is sending twenty employees to each session held there. The Commission accepts ten cadets for each session of the school and the field training. In 1970 only one session was held, but in 1971 the course was expanded to two sessions. So far, ninety men, employees and cadets, have completed the course.

The Arkansas Planning Commission, in cooperation with the Bureau of Outdoor Recreation, has completed a study of the loss of wetlands and woodlands in Eastern Arkansas. Although the detailed study was limited to the Arkansas portion of the Mississippi River Delta Region, essentially the same conditions prevail in the Delta portions of five other states and the recommendations to alleviate the problem are applicable Regionwide. Shortly after the study got underway, it was recognized that the destruction of wetlands, woodlands and other environmental qualities in the Delta was precipitating losses which extend far beyond what is generally believed to be the limits of conservation interests. In the fall of 1969, Governor Winthrop Rockefeller directed attention to the far-reaching effects of the losses of these resource values by calling a multistate seminar to discuss possible solutions to the problem.