Age Determination Methods For Fishes Studied By The Groundfish Program At The Pacific Biological Station

This manual describes methods and equipment used to estimate the ages of groundfish species studied by the Pacific Biological Station. Procedures for routine identification of annuli on scales, otoliths, otolith section, fin-ray sections, and spines are described and illustrated. Although the techniques are applied to species found off Canada's west coast, they should be applicable to other marine and freshwater fishes from temperate and arctic waters. Because some of the procedures are experimental and many have not been validated, it is expected that this manual will be revised several times.

The Age and Growth Program at the Alaska Fisheries Science Center is tasked with providing age data in order to improve the basic understanding of the ecology and fisheries dynamics of Alaskan fish species. The primary focus of the Age and Growth Program is to estimate ages from otoliths and other calcified structures for age-structured modeling of commercially exploited stocks; however, the program has recently expanded its interests to include numerous studies on topics ranging from age estimate validation to the growth and life-history of non-target species. Because so many applications rely upon age data and particularly upon assurances as to their accuracy and precision, the Age and Growth Program has developed this practical guide to document the age determination of key groundfish species from Alaskan waters. The main objective of this manual is to describe techniques specific to the age determination of commercially and ecologically important species studied by the Age and Growth Program. The manual also provides general background information on otolith morphology, dissection, and preparation, as well as descriptions of methods used to measure precision and accuracy of age estimates. This manual is intended not only as a reference for age readers at the AFSC and other laboratories, but also to give insight into the quality of age estimates to scientists who routinely use such data.

Biology of Antarctic Fish presents the most recent findings on the biology of fish in the unique environment of the Antarctic ocean. At present the year-round temperature of the coastal waters is very near -1,87 ° C, the equilibrium temperature of the ice-seawater mixture. This extremely low temperature affects different levels of organization of fish life: individuals, organ systems, cells, organelles, membranes, and molecules. Exploring ecology, evolution, and life history as well as physiology, biochemistry, and molecular biology of Antarctic fish the book describes the mechanisms of cold adaptation at all these levels. It provides material for discussion also for fundamental questions in the field of adaptation to an extreme environment and therefore is of particular interest not only to specialized scientists, but also to those involved in basic and evolutionary biology.

This landmark publication collates information and studies on the use of estuaries, and specific habitats within them, as nursery, feeding and refuge areas, and migration routes of marine and other fish, many of which are of commercial and conservation importance. The editors and authors of the book have carefully compiled a huge wealth of information from the work of 18 organizations across 11 countries, providing a unique collection of data never before brought together within the covers of one book. Chapters within this exceptional publication cover habitat use by fishes, recruitment and production in estuaries, links between fish and other trophic levels, endangered and rare species, estuarine development and restoration, environmental quality of estuaries and the management of estuarine fishes. The book notably contains extensive chapters on field methods and data analysis. Fishes in Estuaries is an essential tool and reference source for fisheries and environmental managers, fish biologists, environmental scientists, aquatic ecologists and conservation biologists. Libraries in all universities and research establishments where biological sciences are studied and taught should have copies of this book on their shelves, as should personnel employed in regulatory and consultant capacities, such as within rivers authorities, environment agencies and fish and wildlife departments. Comprehensive coverage of commercially exploited species. Internationally known and respected contributors. Multi-contributor approach providing very detailed coverage. Estuaries are a vitally important ecosystem.