Spotted bass, Micropterus punctulatus, were studied in Bull Shoals Reservoir during 1966-71 to determine some of the environmental requirements for successful spawning and to estimate the reproductive potential of the species.

Smallmouth bass were studied in Bull Shoals Lake to determine the nesting requirements and reproductive capabilities of the species in a reservoir. Underwater observations were conducted weekly in five study areas during the spawning seasons of 1969-76. Length of spawning season was affected by the rate of water temperature rise during the nesting period. Active nests were found at ambient temperatures of 13.3-22.5 degrees Centigrade. Nest were generally on gently sloping rock and gravel bottoms, beside permanent objects such as rocks or sunken logs, and at densities of less than one per 100 m of shoreline.

Centrarchid fishes, also known as freshwater sunfishes, include such prominent species as the Largemouth Bass, Smallmouth Bass and Bluegill. They are endemic to Eastern North America where they form part of a multi-million dollar sports fishing industry, but they have also been widely introduced around the globe by recreational anglers, in aquaculture programs and by government fisheries agencies. Centrarchid Fishes provides comprehensive coverage of all major aspects of this ecologically and commercially important group of fishes. Coverage includes diversity, ecomorphology, phylogeny and genetics, hybridization, reproduction, early life history and recruitment, feeding and growth, ecology, migrations, bioenergetics, physiology, diseases, aquaculture, fisheries management and conservation. Chapters have been written by well-known and respected scientists and the whole has been drawn together by Professors Cooke and Philipp, themselves extremely well respected in the area of fisheries management and conservation. Centrarchid Fishes is an essential purchase for all fish biologists, ecologists, fisheries managers and fish farm personnel who work with centrarchid species across the globe.

The time and location of spawning, food and larvae, and habitats used as nursery areas by young-of-the-year fishes were studied from 1972 to 1975 in South Dakota waters of Lake Oahe, a main stem Missouri River reservoir. Sampling locations were in the tributary rivres -- the Grand Moreau, and Cheyenne -- and their embayments. Year-class strength of river-spawning species was strongly correlated with river flow rates during the spawning season. Success of reservoir-spawning species was primarily dependent on above-average water levels, which inundated terrestrial vegetation to provide a substrate for egg deposition and cover for larvae. Preserving adequate streamflow and enhancing reservoir shoreline areas by managing water levels, seeding vegetation, and eliminating grazing alongshore would probably ensure adequate reproduction of most areas.

Application of the organophosphate insecticide Abate three times (at about monthly intervals) to duplicate 0.04 ha earthen ponds at 18 g/ha (4 micrograms/liter) -- the recommended application rate -- and 180 g/ha (40 micrograms/liter) caused no mortality on blugills. In ponds treated with 18 g/ha fewer bluegill fry were produced than in control ponds, brain acetylcholinesterase (AChE) activity was not affected, and accelerated growth of both fry and adults appeared to result from heavy feeding on dead or moribund Diptera larvae that resulted from the first two applications of Abate. The routine use of Abate at the recommended rate should have little adverse effect on fishery resources.

Significant changes have occurred in the distribution of trout in streams of Great Smoky Mountains National Park since 1900. By the mid-1970's the original range of the native brook trout had been reduced by about 70% and the species was relegated to suboptimal habitat in head water streams. Most of the stream sections lost by brook trout became the territory of the introduced rainbow trout, which in 1977 occupied about 80% of the Park waters. After 1950, brown trout introduced in State waters outside the Park established reproducing populations in some 50 miles of stream formerly occupied only by rainbow trout. If current trends continue, the recovery of brook trout in Park water may be difficult, if not impossible, and brown trout may occupy much of the territory now held by rainbow trout.

Clinical methods are presented for biological monitoring of hatchery and native fish populations to assess the effects of environmental stress on fish health. The choice of methods is based on the experience of the authors and the judgment of colleagues at fishery laboratories of the U.S. Fish and Wildlife Service. Detailed analysis methods, together with guidelines for sample collection and for the intrepretation of results, are given for tests on blood (cell counts, chloride, cholesterol, clotting time, cortisol, glucose, hematocrit, hemoglobin, lactic acid, methemoglobin, osmolality, and total protein); water (ammonia and nitrate content); and liver and muscle (glycogen content).

Toxicities of four chemical forest fire retardants, Fire-Trol 100 and 931 (ammonium sulfate, or polyphosphate with an attapulgit clay thickner) and Phos-Chek 202A and 259 (diammonium phosphate with guar gum derivative thickner) were determined by static and flow-through toxicity tests for fry and fingerling coho salmon and rainbow trout; fingerling fathead minnows, bluegills, and largemouth bass; and mature scuds. In static tests, Phos-Chek formulations were more toxic than either of the Fire-Trol formulations to scuds and all life stages of fish. In salmon and trout, fry were generally more susceptible than fingerlings to all formulations; yolk-sac fry were more susceptible than swim-up friy. Toxicities of all formulations to salmon and trout were similar at 6 to 11 degress centigrade. Un-ionized ammonia is believed to be the most toxic component of thes fire retardants.