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.

Estuarine Processes, Volume I: Uses, Stresses, and Adaptation to the Estuary provides information pertinent to estuarine processes and focuses on dynamic interactions at several levels of organization. This book presents the strategies to rehabilitate and protect estuaries. Organized into seven parts encompassing 37 chapters, this volume begins with an overview of the alternative ways of attaining the pervasive goals of pollution abatement and estuarine management. This text then discusses the significance of maintaining estuarine environment quality if fisheries are to continue. Other chapters consider the great value of the estuarine zone, which lies in the multiplicity of uses it serves, but herein also lies its vulnerability. This book discusses as well the identification of the major factors regulating phytoplankton productivity and regulating the level of phytoplankton biomass. The final chapter deals with assessing the potential deleterious effects of certain toxicants to penaeid shrimp. This book is a valuable resource for ecologists, environmentalists, and scientists.