Salmonid Fishes

This important title encompasses features of genetic processes in complexly organised population systems of salmonids, one of the most commercially valuable families of fish worldwide. Translated from the original work in Russian, the authors have taken the opportunity to update and revise the work, much of it appearing in the English language for the first time. Covering such important concepts as optimal gene diversity and the unfavourable influence of fishery and hatchery reproduction on the genetic structure of salmon populations, the authors have drawn together a huge wealth of information that will form the cornerstone of much new work in the future. The authors of Salmonid Fishes have between them many years of research experience and practical knowledge in the area and the English translation of this important work, which has been edited by Professor John Thorpe and Professor Gary Carvalho, provides vital information for all those involved in salmonid management, exploitation and conservation, including fish biologists, fisheries managers, conservation and population biologists, ecologists and geneticists.

As the human population increases and nations become more industrialized, the habitat and water quality required for the survival of fish continues to decline. In addition to these environmental factors, fish populations are directly or potentially affected by harvesting, enhancement programs and introgression with hatchery-propagated or transgenic fish. To our knowledge no other scientific meeting has been assembled to consider the breadth of the problem, to review the technology that is presently available for the preservation of the germ plasm of salmonid stocks and to identify the scientific advances that are required to overcome the problems. Because many salmonids have spawning grounds within the confines of a specific region or county but will spend a large portion of their life cycle within the territorial waters of other countries or in the open ocean, the preservation of unique genes or gene pools in these animals requires international cooperation. This scientific meeting has provided a forum in which to discuss the problems, evaluate the present methods or technology for addressing the problems and suggest new directions or innovations that need to be implemented. During this meeting we limited our discussion to salmonid fishes. However, the general conclusions about the factors that affect the population dynamics of fish stocks and the technical aspects concerning the preservation of germ plasm will be applicable to other fish species.

Incidence of acid-fast bacillus infections in salmonid fishes at West Coast hatcheries was determined for 1957-59. No evidence was obtained which would indicate a definite trend towards either increased or decreased rates of infection. It is apparent that the incidence of infection is higher in hatchery-marked fish than in unmarked fish. Only one hatchery was found free of infection during the 3 years covered by the investigation. This installation had never used raw salmon products in diet.