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J. W. Meade

Publications and source records attributed to J. W. Meade.

At least 19 recordsLinked to original sources
USGS2009

Effects of cumulative loading level, as fish weight per unit flow, on water quality and growth of lake trout

Lake trout, Salvelinus namaycush , were cultured in a series of five rearing units (in triplicate). The fish removed available oxygen in each unit, from about 10.5 to 7.0 mg/L. Oxygen was replaced, through aeration, between rearing units. Effects of cumulative loading, as fish weight/flow rate, are described in terms of water quality and fish growth. In fish reared at the highest loading level, mean growth during the 2-month cumulative loading period was depressed by more than half. However, the growth rate progressively increased in those fish reared under high loading levels, indicating acclimation of the fish to high metabolite concentrations. After two months of series-reuse rearing, cumulative loading was removed through introduction of fresh water (noreuse) to each unit, and fish recovery was monitored. During recovery, mean growth of fish that had been reared under the highest cumulative loading level was equal to or greater than that of fish that had been reared under the low loading levels.

Journal of the World Mariculture Society↗
USGS1994

Evaluation of the effects of an oxygen injection system on the growth, hematology, and immunity of lake trout

Fingerling lake trout ( Salvelinus namaycush ) were reared for 64 d at three pressures of dissolved gases, expressed in relation to saturation values (▵P)–untreated (control) water, ▵P = 10 mm Hg; water treated by column degassing with air, ▵P = 9 mm Hg; and water treated with an oxygen injection system, ▵P = −20 mm Hg. Dissolved oxygen concentration for experimental groups was increased with column degassing by 7.8% and with oxygen injection by 8.7%. Nitrogen level was reduced 2.2% with columns receiving air and 7.4% with the oxygen injection system. There were no differences in production, mean lengths, or mean weights among fish reared in the three treatments. Hematocrit, plasma protein levels, and mean antibody microtiters to injected Salmonella H antigen were not different among fish from the three water treatments.

Progressive Fish-Culturist↗
USGS1993

Growth, survival and food conversion of Atlantic salmon reared at four different densities with common water quality

Our objective was to determine the maximum effective rearing density for Atlantic salmon ( Salmo salar ) at 17.5°C, a temperature typically used in hatcheries to accelerate growth. We reared 5.8‐g (mean weight) parr for 80 d to final rearing densities of 14–55 kg/m 2 (rearing unit bottom area) or 80–310 kg/m 3 (rearing unit volume). Weight gain was slightly depressed in fish at a final rearing density of 26 kg/m 2 (146 kg/m 3 ), but mortality, food conversion, and gain in length were not affected. At densities greater than 26 kg/m 2 , fish growth was slower and food conversion was higher, but mortality was unaffected. Atlantic salmon may be reared at 17.5°C to densities of at least 14 kg/m 2 (80 kg/m 3 ) without adverse effects on growth and health, but final rearing densities should not exceed 26 kg/m 2 .

Progressive Fish-Culturist↗
USGS1993

Fin condition of Atlantic salmon reared at high densities in heated water

We assessed the condition of dorsal and pectoral fins of parr of Atlantic salmon Salmo salar that were reared for 70 d at 17.5°C to final densities of 14–55 kg/M 2 (rearing-unit bottom area) or 80–310 kg/m 3 (rearing-unit volume). Pectoral fins were not significantly affected by rearing density, but dorsal fins were more eroded in fish reared at the highest density than in fish checked before the rearing experiments or in those reared at lower densities. Densities as great as 41 kg/m 2 (229 kg/m 3 ) did not affect fin quality of Atlantic salmon reared at 17.5°C.

Journal of Aquatic Animal Health↗
USGS1992

Effects of sodium and calcium on acute toxicity of un-ionized ammonia to Atlantic salmon and lake trout

Acute, static 6-hour toxicity tests were conducted on two sizes each of lake trout and Atlantic salmon in the presence of three levels each of NaCl and CaCl 2 . Calcium did not protect smolts from NH 3 toxicity but had no effect on the tolerance of Atlantic salmon fry to NH 3 . Both cations increased the tolerance of 8-g lake trout fingerlings to NH 3 , but neither significantly affected the toxicity of NH 3 to 0.9-g lake trout fry. These results suggest that the mitigating effects of solution cations of NH 3 toxicity may be related to species, size, and life stage.

Journal of Applied Aquaculture↗
USGS1991

The effects of ionic strength on un-ionized ammonia concentration

Ionic strength affects the ionization of ammonia and the resulting un‐ionized ammonia (NH 3 ) concentration. The error introduced by failure to account for this effect can be substantial in marine or brackish water. We present a simple method for correcting the calculation of the NH 3 fraction in an ammonia solution for ionic strength.

Progressive Fish-Culturist↗
USGS1990

Modeling the effects of serial off-gas reuse on the performance of a hooded surface oxygen obsorption system

A numerical model was used to evaluate the performance of a surface agitation system designed to contact commercial oxygen with water. The modeled system was unique in that oxygen-rich off-gas, normally discharged to the atmosphere, was directed in serial reuse through additional contact stages receiving untreated water. A correlation between the agitator mass-transfer coefficient and power demand, needed to calibrate the model, was established using a single-stage (37 W) contactor of 1·18 m 3 capacity. Additional tests, conducted with both single and three-stage equipment, verified model assumptions and performance predictions. Simulation runs indicated oxygen flow or power input required to meet a given effluent dissolved gas criterion can be substantially reduced by the off-gas reuse step; for example, to achieve an effluent dissolved oxygen of 24·1 mg/litre with a single stage agitator the oxygen feed rate needed was 61·5% greater than that required by a six-stage system receiving the same total power input (standard aeration efficiency, 0·5 kg/kW h; water flow rate, 100 litre/min; influent dissolved oxygen, 9·08 mg/litre at 15°C). The savings achieved increased with (1) greater target effluent dissolved oxygen concentrations, (2) lower oxygen feed rates, (3) higher input power levels, and (4) number of contact stages.

Aquacultural Engineering↗
USGS1990

Effect of feeding rate and gas supersaturation on survival and growth of lake trout

Fingerling lake trout ( Salvelinus namaycush ) were reared for 35 d in water with total dissolved gas pressures of 46, 78, 108, or 159 mm Hg above ambient conditions (▵P). Within each gas pressure treatment, daily feeding rations were (1) 1.7% of the total weight offish in the heaviest of three replicates, (2) 1.7% of the weight of fish in each individual tank, or (3) 0.9% of the weight in each tank (underfeeding). Signs of gas bubble trauma were first observed as hemorrhagic spots on the eyes of some fish reared at ▵P = 46, and external evidence of trauma increased as ▵P increased. All fish sampled at ▵P = 159 showed signs of gas bubble disease; the most common were eye hemorrhage and bubble formation inside the mouth. Mortality was 11% or less among fish reared at gas levels up to ▵P = 108. Mortality was as high as 55% at ▵P = 159, but did not differ among feeding treatments. Net weight gain by fish was low at ▵P = 159 because of both high mortality and slow growth. Growth was slowest for underfed fish at all gas levels, and underfed fish consistently showed increasing injury as gas pressures increased. Calculation of feeding rate on the basis of fish weight in individual tanks allowed the most cost‐efficient food distribution. Culture of lake trout at ▵P < 46 is recommended.

Progressive Fish-Culturist↗
USGS1988

A bioassay for production capacity assessment

Given sufficient oxygen, fish production can be limited by a multiplicity of factors. Accurate determination of production capacity requires something other than an estimate of the biomass at which ambient un-ionized ammonia will reach a recommended, non-site-specific, maximum safe concentration. A chronic (1- to 2-month) bioassay can be used to determine the point at which metabolite buildup reduces growth by some predetermined proportion, or causes unacceptable tissue damage. The bioassay is conducted as a series reuse, single-pass system, in which incoming water to each rearing unit is aerated to 90% dissolved oxygen saturation. The assessment of production capacity is based on the relation between cumulative oxygen consumption and growth reduction.

Aquacultural Engineering↗
USGS1987

Acceptability of fairy shrimp (Streptocephalus seali) as a diet for larval fish

Fairy shrimp (Streptocephalus seali), brine shrimp (Artemia salina), and a pelleted food were fed to tiger muskellunge (the hybrid of muskellunge, Esox masquinongy, and northern pike, E. lucius) to compare acceptability and nutritional value of the diets. Fairy shrimp, although less nutritious than the pelleted diet, provided a suitable freshwater alternative to brine shrimp.

Progressive Fish-Culturist↗
USGS1987

Effects of rearing density on growth, survival, and fin condition of Atlantic salmon

Parr of Atlantic salmon (Salmo salar) were reared to final densities of 0.53‐4.29 lb/ft 2 of rearing container bottom area under conditions of constant temperature, water quality, and diet. Growth and survival were not affected by density. After 171 d, the condition of pectoral and dorsal fins had not changed from that initially recorded and did not differ among treatments. We conclude that rearing density alone does not affect growth, survival, or fin condition of Atlantic salmon reared at densities likely to occur at production hatcheries.

Progressive Fish-Culturist↗