The catch of scup over the past 50 years has fluctuated widely. Data on this fishery for recent years (1922-35), obtained from State and Federal agencies, commercial fishery, and fishermen, have been analysed to determine causes of fluctuations. It was found that fluctuations in the summer fishery from New Jersey to Massachusetts were caused mainly by differences in the size of the successive year classes entering the fishery. Fluctuations in the catch of the winter trawl fishery off the Virginia Capes resulted from changes in the amount of cooling of the bottom water where these fish are found in winter. During cold-water conditions, the fish became more concentrated and were more easily caught; whereas, when the water was warmer, the fish scattered more widely and were not as readily available. Although fluctuations in catch of the summer and winter fishery have different causes, results of tagging and observations of size composition have disclosed that both fisheries draw on the same general stock.

Ecological studies on the fresh-water phases of the life history of sockeye salmon and studies on related limnology and climatology were made at Brooks Lake, Alaska, in 1957. Data are presented and interpreted on adult sockeye salmon spawning distributions and behavior, age, sex, length, fecundity, and bear predation; on juvenile sockeye salmon ages, food, growth, migration from the lake, relative abundance, and distribution in the lake; and on climatological and limnological factors that may influence sockeye salmon behavior and abundance.