Distribution, Abundance, and Growth of Juvenile Sockeye Salmon, Oncorhynchus Nerka, and Associated Species in the Naknek River System, 1961-64 (Classic Reprint) PDF Download
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Author: Robert J. Ellis
Publisher: Forgotten Books
ISBN: 9780666204707
Category : Business & Economics
Languages : en
Pages : 68
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Book Description
Excerpt from Distribution, Abundance, and Growth of Juvenile Sockeye Salmon, Oncorhynchus Nerka, and Associated Species in the Naknek River System, 1961-64 Mean number of age 0 and age I sockeye salmon taken in Naknek River system, August 1961-64. Relative abundance of spawning grounds and average catch per unit of effort of age 0 sockeye salmon in July 1961-63 in lakes of the Naknek River system. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.
Author: Robert J. Ellis
Publisher: Forgotten Books
ISBN: 9780666204707
Category : Business & Economics
Languages : en
Pages : 68
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Book Description
Excerpt from Distribution, Abundance, and Growth of Juvenile Sockeye Salmon, Oncorhynchus Nerka, and Associated Species in the Naknek River System, 1961-64 Mean number of age 0 and age I sockeye salmon taken in Naknek River system, August 1961-64. Relative abundance of spawning grounds and average catch per unit of effort of age 0 sockeye salmon in July 1961-63 in lakes of the Naknek River system. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.
Author: Robert J. Ellis
Publisher:
ISBN:
Category : Fishes
Languages : en
Pages : 0
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Author: Robert J. Ellis
Publisher:
ISBN:
Category :
Languages : en
Pages : 53
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Author: Bruce L. Wing
Publisher:
ISBN:
Category : American lobster
Languages : en
Pages : 18
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Author: Richard L. Wallace
Publisher:
ISBN:
Category : Estuarine ecology
Languages : en
Pages : 290
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A study of the distribution, relative abundance and diet of fishes sympatric with juvenile sockeye salmon, Oncorhynchus nerka (Walbaum), within the freshwater nursery areas of the Naknek River system was undertaken from 1961 to 1963. The study was part of an extensive investigation to determine what factors in the freshwater environment were limiting the size of the populations of sockeye salmon returning to the rivers of Bristol Bay, Alaska. The speties found associated with juvenile salmon in the limnetic zones of the Naknek system were the pond smelt, Hypomesus olidus (Pallas); the least cisco, Coregonus sardinella Valenciennes; the threespine stickleback, Gasterosteus aculeatus Linnaeus; and the ninespine stickleback, Pungitius pungitius (Linnaeus). Life history information was collected for these sympatric species. Tow nets were used to capture samples of fish from the limnetic portions of the nursery areas. Some samples were collected by beach seines, lake traps and otter trawls. Plankton samples were collected and compared to the diets of the limnetic fishes. Although some confusion has existed in the literature, I concluded that pond smelt of the Naknek system belong to Hypomesus olidus (Pallas). The populations of smelt were comprised of six age-groups in the late summer, but most specimens belonged to three age-groups. Most members of the species spawn in the spring of the fourth year of life. The estimated fecundity ranged from 900 to 4,300 eggs per female. Seven age-groups of least ciscoes were present in the populations of the Naknek system. The species in the Naknek system probably spawned for the first time in the fall of their fourth year. The estimated fecundity of two specimens was 4,006 and 14,380 eggs. Populations of three spine stickleback were comprised of three age-groups of fish. I was unable to assign ages to ninespine stickleback. Estimates of the fecundity of the species ranged from 116 to 456 eggs per female. All species studied were distributed throughout the Naknek system. The relative abundance of the fishes studied was variable between and within nursery areas and from year to year. The population densities of pond smelt and threespine stickleback were larger in the surface waters compared to the deep waters. The relative abundance of sockeye fry, yearlings and ninespine stickleback was greater in the surface stratum rather than the deep stratum in most nursery areas. The five main food items utilized by these limnetic species were cladocerans (Bosmina sp. and Daphnia sp.); copepods (cyclopoid copepods and Diaptomus sp.); and Dipteran insects. Analysis of the similarity of diets indicated that the diets of sockeye fry and pond smelt were more similar than were the diets of sockeye fry or yearlings and any other sympatric species. The diet of sockeye fry was more similar to that of either species of stickleback than was the diet of sockeye yearlings. An analysis of the food of various sizes of each species of fish indicated the diets of three age-groups of smelt were more similar than the diets of various age-groups of any other fish. The food composition of three age-groups of ciscoes and two size groups of both species of stickleback showed a strong positive correlation. The diets of sockeye fry and yearlings showed the weakest positive correlation of the species studied. All species of fish studied selectively fed on one or more components of the zooplankton. Daphnia sp. and cyclopoid copepods were strongly selected in Lake Coville. Cyclopoids were selected in South Bay. Bosmina sp. was selected from the waters of West End. In Lake Coville, the greatest potential competition for food probably existed between the large populations of pond smelt and sockeye fry. In the West End nursery area, potential competition between juvenile salmon and both species of stickleback may not be severe, depending on the age composition of the salmon population present in the nursery area. The possibility exists that the relatively low numbers of adult sockeye salmon returning to the comparatively rich lakes of the Naknek River system is due to the presence of large populations of sympatric species of fish. Each of these sympatric species feed on the same general types of food organisms as do the juvenile salmon and may affect the numbers of young salmon that leave the lake, and subsequently return from the ocean.
Author: Robert J. Ellis
Publisher:
ISBN:
Category : Sockeye salmon
Languages : en
Pages : 160
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Author: Jeremy M. B. Hume
Publisher: Cultus Lake, B.C. : Fisheries and Oceans Canada, Science
ISBN:
Category :
Languages : en
Pages : 126
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Juvenile sockeye salmon rearing in Babine Lake were re-examined 22 years after the initiation of the Babine Lake Development Project (BLDP). Abundance, distribution, size, and species composition of the limnetic fish populations, including juvenile sockeye salmon, were determined by hydroacoustic and midwater trawl surveys in the autumn of 1993 and the summer and fall of 1994 and 1995 and compared to results collected before and shortly after the start of the BDLP. Our objectives were to look for: 1) changes in the abundance of juvenile sockeye relative to spawning numbers; 2) changes in the utilization of the available nursery area; and 3) the effects of increased popualtion size and density on the size and growth of juvenile sockeye.
Author: Ronald Albert Iverson
Publisher:
ISBN:
Category : Sockeye salmon
Languages : en
Pages : 144
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The life history of juvenile sockeye salmon (Oncorhynchus nerka) resident in Chignik River, Alaska, represents a departure from the lacustrine, pelagic existence typical of juveniles of this species. For this reason, the distribution, relative abundance in different parts of the river, growth, and upstream and downstream movements of juvenile sockeye in the river were studied during the summers of 1963 and 1964. The objectives of the study were to gain information on the possible origins of juvenile sockeye resident in Chignik River, and on the role of Chignik River in production of sockeye salmon. Distribution and abundance were estimated by seining and underwater observation. Juvenile sockeye appeared to be restricted to quiet waters along the shore. Catches of sockeye fry tended to increase through the summer, whereas catches of yearlings decreased. Smolts were taken in significant numbers only in June and July. early summer, large numbers of yearling sockeye were concentrated in Chignik River just below the outlet of Chignik Lake. In sockeye fry and yearlings captured in the lower river were generally larger than those captured in the upper river. Juvenile sockeye in the upper river grew slower than those in most other parts of the watershed. Scale analysis of sockeye salmon spawning in Chignik River showed that these fish entered the ocean at a larger size than did fish reared in Chignik Lake or Chignik River. This suggests that at least part of the progeny of river spawners do not remain in the river, but descend as fry to the brackish estuary, where growth conditions are superior. Upstream movement of schools of yearling sockeye was observed in the upper portions of the river. Such a movement has been observed many times in Chignik River in past years and has at times involved large numbers of fish. Schools of yearling sockeye have been observed to enter Chignik Lake. Fish of the same size group were captured while moving downstream at the lake outlet at night, suggesting a circular movement involving displacement of fish into the river at night and a positive rheotactic response causing them to re-enter the lake during the day. Juvenile sockeye salmon resident in Chignik River may include both progeny of river spawners, and fish which have moved down from Chignik Lake; Chignik Lake is probably the more important source. Chignik River is judged to have a minor role in the production of sockeye salmon, relative to the other rearing areas in the watershed.
Author: Donald E. Rogers
Publisher:
ISBN:
Category : Fishes
Languages : en
Pages : 92
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Book Description
Author: Michael L. Dahlberg
Publisher:
ISBN:
Category : Salmon
Languages : en
Pages : 344
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