Author: Publisher:
ISBN:
Category : Atmosphere
Languages : en
Pages : 324
Book Description
NOAA Professional Paper
Author: Improving Fish Stock Assessments
Author: National Research CouncilPublisher: National Academies Press
ISBN: 0309174406
Category : Technology & Engineering
Languages : en
Pages : 194
Book Description
Ocean harvests have plateaued worldwide and many important commercial stocks have been depleted. This has caused great concern among scientists, fishery managers, the fishing community, and the public. This book evaluates the major models used for estimating the size and structure of marine fish populations (stock assessments) and changes in populations over time. It demonstrates how problems that may occur in fisheries dataâ€"for example underreporting or changes in the likelihood that fish can be caught with a given type of gearâ€"can seriously degrade the quality of stock assessments. The volume makes recommendations for means to improve stock assessments and their use in fishery management.
Genetic and Morphological Identification of Pelagic Juvenile Rockfish Collected from the Gulf of Alaska
Author: Arthur W. Kendall (Jr.)Publisher:
ISBN:
Category : Electronic books
Languages : en
Pages : 32
Book Description
Age Determination Manual of the Alaska Fisheries Science Center Age and Growth Program
Author: Mary Elizabeth MattaPublisher:
ISBN:
Category : Fishes
Languages : en
Pages : 114
Book Description
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.
Larval Development and Identification of the Genus Triglops (Scorpaeniformes: Cottidae)
Author: Deborah M. BloodPublisher:
ISBN:
Category : Cottidae
Languages : en
Pages : 56
Book Description
Prior to Pietsch's (1993) revision of the genus Triglops, identification of their larvae was difficult; six species cooccur in the eastern North Pacific Ocean and Bering Sea and three co-occur in the western North Atlantic Ocean. We examined larvae from collections of the Alaska Fisheries Science Center and Atlantic Reference Centre and used updated meristic data, pigment patterns, and morphological characters to identify larvae of Triglops forficatus, T. macellus, T. murrayi, T. nybelini, T. pingeli, and T. scepticus; larvae of T. metopias, T. dorothy, T. jordani, and T. xenostethus have yet to be identified and are thus not included in this paper. Larval Triglops are characterized by a high myomere count (42-54), heavy dorsolateral pigmentation on the gut, and a pointed snout. Among species co-occurring in the eastern North Pacific Ocean, T. forficatus, T. macellus, and T. pingeli larvae are distinguished from each other by meristic counts and presence or absence of a series of postanal ventral melanophores. Triglops scepticus is differentiated from other eastern North Pacific Ocean larvae by having 0-3 postanal ventral melanophores, a large eye, and a large body depth. Among species co-occurring in the western North Atlantic Ocean, T. murrayi and T. pingeli larvae are distinguished from each other by meristic counts (vertebrae, dorsal-fin rays, and anal-fin rays once formed), number of postanal ventral melanophores, and first appearance and size of head spines. Triglops nybelini is distinguished from T. murrayi and T. pingeli by a large eye, pigment on the lateral line and dorsal midline in flexion larvae, and a greater number of dorsal-fin rays and pectoral-fin rays once formed.
Atlas of Abundance and Distribution Patterns of Ichthyoplankton from the Northeast Pacific Ocean and Bering Sea Ecosystems Based on Research Conducted by the Alaska Fisheries Science Center (1972-1996)
Author: Potential Overlap Between Cetaceans and Commercial Groundfish Fleets that Operate in the California Current Large Marine Ecosystem
Author: Blake Edward FeistPublisher:
ISBN:
Category : Cetacea
Languages : en
Pages : 40
Book Description
Cetacean populations are confronted by many anthropogenic threats, including commercial whaling, noise, vessel collisions, gear entanglement, exploitative competition, habitat disturbance, and global climate change. Evidence indicates that commercial fishing activities can have both direct (e.g., gear entanglement and bycatch) and indirect (e.g., prey reduction and noise) effects on cetaceans. However, few studies have addressed the potential vulnerability of a given cetacean species to an entire fishing fleet that operates over a large marine ecosystem. In this study, we overlaid spatially explicit multiyear predicted mean densities of 11 cetacean species and 1 species guild within the California Current Large Marine Ecosystem with data for commercial fishing effort of the fixed-gear, at-sea hake mid-water trawl, and bottom trawl fleets of the west coast groundfish fishery. We quantified the exposure of each species to each fleet type by multiplying the predicted mean cetacean density by the measured fishing fleet effort. We found large interspecific and interfleet variability in the overlap between cetaceans and fishing fleets. Although many of the species had relatively low overlap rates, others had substantial exposure to some of the fishing fleets, particularly those species with more nearshore distributions. Direct mortality from these fleets has been documented to be low, but our results indicate that there is opportunity for fisheries interactions with some cetacean species, particularly in the fixed-gear fleet. Our analyses make up an important first step in generating formal risk assessments for quantification of the impacts of various fishing fleets on populations of cetacean species that occur in the California Current.
Guide to the Identification of Larval and Early Juvenile Pricklebacks (Perciformes: Zoarcoidei: Stichaeidae) in the Northeastern Pacific Ocean and Bering Sea
Author: Ann C. MataresePublisher:
ISBN:
Category : Stichaeidae
Languages : en
Pages : 104
Book Description
Emerging Technologies for Reef Fisheries Research and Management
Author: James Christopher TaylorPublisher:
ISBN:
Category : Coral reef ecology
Languages : en
Pages : 132
Book Description
This publication of the NOAA Professional Paper NMFS Series is the product of a special symposium on "Emerging Technologies for Reef Fisheries Research and Management" held during the 56th annual Gulf and Caribbean Fisheries Institute meeting in Tortola, British Virgin Islands, November 2003. The purpose of this collection is to highlight the diversity of questions and issues in reef fisheries management that are benefiting from applications of technology. Topics cover a wide variety of questions and issues from the study of individual behavior, distribution and abundance of groups and populations, and associations between habitats and fish and shellfish species.
An Annotated Checklist of the Marine Macroinvertebrates of Alaska
Author: David Thomas DrummPublisher:
ISBN:
Category : Marine animals
Languages : en
Pages : 308
Book Description
A current and comprehensive species list of marine invertebrates of Alaska is essential for effective management of living marine resources, sustainable fisheries, conservation of vulnerable ecosystems, and advancement of our knowledge of biodiversity and ecosystem function. Furthermore, the most current checklist available to resource managers and scientists is quite dated and limited in that it only includes the marine invertebrates of the southern coast of Alaska to California. Since that checklist was published, many new species have been described, many range extensions have been discovered, and considerable changes in higher-level systematics have been made. The checklist that we have compiled lists 3708 species and presents for each species the currently accepted scientific name and its significant synonyms, common names, type localities, geographic and depth distributions, a general statement of abundance in Alaska when known (e.g., rare, uncommon, common, abundant), and general remarks. It includes species recorded in the marine waters of Alaska from the intertidal zone, continental shelf, and upper continental slope to abyssal depths, from the Beaufort Sea at the Arctic border with Yukon, Canada; the eastern Chukchi Sea, the eastern Bering Sea, the Aleutian Islands to the western border with Russia; and the Gulf of Alaska to Dixon Entrance at the southern border with British Columbia. Sound and reliable taxonomic identifications are necessary to monitor and predict changes in the distribution and abundance of marine species. The current status and future direction of the study of Alaskan marine invertebrate biodiversity are briefly discussed.