Significantly higher numbers of aquatic insects were sampled in treated ponds than in untreated, and insect numbers at high-treatment ponds were significantly higher than at low-treatment ponds. Chironomids were dominant and significatnly increased after a certain level of treatment. Chironomids comprised 74 percent of samples from high-treatment ponds, but only 43 and 42 percent respectively fro untreated and low-treatment ponds. Methoxychlor residues were not detectable in pond-bottom mud samples.

Studies on two hemoflagellates of fish were carried out to determine biological parameters: host range, vector relations, in vivo culture, in vitro culture, pathogenicit, and cryogenic preservation.

Feeding trials using fall chinook salmon finglerlings were conducted at the Salmon Cultural Laboratory, Longview, Washington, during 1971 for the purpose of improving the Abernathy diet formula. The results indicated that cottonseed meal could replace a portion of the fish meal in the diet without reducing fish growth, but similar substitutions of wheat and corn gluten meal reduced growth. Fish growth was significantly increased when a diet containing 50 percent protein and 3,350 kcal per kilogram was fed as compared with a diet containing 45 percent protein and 3,350 kcal per kilogram. Soybean lecithin proved to be equal to soybean oil as a caloric source when fed at 2 percent of the diet. Two types of dried whey product with different levels of lactose content produced similar growth response. Reducing the dried whey portion of the diet to 5 percent did not affect growth, nor did methionine supplementation produce any effects. Anchovy meal was unsuitable as a replacement for herring meal.

The total number of adult fish in Lake Frances Case, a main steam Missouri River Reservoir, has declined since impoundment in 1952. Goldeye, channel catfish, and northern redhorse have probably remained the same; emerald shiner, white bass, walleye, and possibly flathead catfish have increased. The sauger population began to decline at about the time walleye numbers increased. Some species formerly present have become rare. Forage species in the reservoir were gizzard shad, emerald shiner, and yellow perch, but these were not present in large enough numbers to provide an abundant forage fish population.