Download or read book Ecological Distribution of Spawning Sockeye Salmon in Three Lateral Streams Brooks Lake Alaska written by David Townsend Hoopes and published by . This book was released on 1962 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A History of Sockeye Salmon Research Karluk River System Alaska 1880 2010 written by Richard Gard and published by . This book was released on 2014 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sport Fishery Abstracts written by and published by . This book was released on 1976 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fishery Bulletin written by and published by . This book was released on 1972 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ecological Studies of Sockeye Salmon and Related Limnological and Climatological Investigations Brooks Lane Alaska 1957 written by Theodore R. Merrell and published by . This book was released on 1964 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Commercial Fisheries Review written by and published by . This book was released on 1964 with total page 1562 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Bibliography of the Eggs Larval and Juvenile Stages of Fishes written by Richard F. Shaw and published by . This book was released on 1980 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Movements of Spawning Sockeye Salmon in Hidden Creek Brooks Lake Alaska written by Setsuwo Tsunoda and published by . This book was released on 1967 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: The movements of a population of adult sockeye salmon (Oncorhynchus nerka) were followed in a small tributary of Brooks Lake, Alaska until spawning was nearly complete in 1963. The objectives of the study were to describe the movements of sockeye salmon on the spawning ground of an entire small stream, to determine factors related to such movements, and to consider the significance of the movements to the species. The spawning run was inventoried at a weir located near the mouth of the tributary. Portions of the run were sampled as they immigrated, and the sampled fish were tagged to enable subsequent identification of individual fish on the spawning ground. Following the initial immigration, daily observations were made to ascertain the location of all fish and the activities of the tagged fish. Tagging had no material effect on either dispersal in the stream or pairing of spawners. The spawning run totalled 2,495; the ratio of males to females was 2.27:1.00, The run consisted preponderantly of males that had spent two winters in the ocean (two ocean-years) and females that had spent three winters in the ocean (three ocean-years). They entered the tributary over a period of 14 days in two waves separated by an interval of three days. The overall median life span in the stream was 12 days in the first wave and eight days in the second wave. The difference was primarily due to predation on the salmon by the brown bear (Ursus arctos). The average female established a redd in 1.4 days; thereafter the females rarely moved far from their redds. The average male required 2.3 days to establish himself in a spawning locale; thereafter most males remained within a relatively small area. The males showed a decided tendency to remain in areas with a high density of females on redds. Fewer females than males overshot their spawning sites. No relation was found between the movements of spawners and either variations of water level or surface water temperature of the stream. Bear predation disrupted spawning activities only locally and temporarily. Males of three ocean-years paired with more females per male than did males of one or two ocean-years. But because of their greater numbers two-ocean-year males participated in more spawnings than did three-ocean-year males. The mean duration of pairing of a particular male with a particular female on a redd was 1.25 days. I concluded that homing within the tributary did not occur; therefore its spawning stock must be a homogeneous unit. The role of the male is primarily one of fertilization of the eggs, not one of defense of territory. Because of the abnormally high ratio of males to females, competition between males for spawning partners resulted in most males of one or two ocean-years being relegated to attend females paired with larger males. Conflict among the males was apparently largely confined within two separate classes of males: males 50 cm or shorter jockeyed among themselves for seemingly preferred positions of attendance next to a pair on a redd, while males 51 cm or longer competed for spawning partners. The polygamous habit in sockeye salmon usually results in a seeming excess of males on the spawning ground beyond the number required to fertilize the eggs. I propose that this "surplus" of males provides a safety factor in times of low numbers in a stock and the competition needed to disperse the males among the available females; both provisions insure fertilization of the available eggs, However, crucial experiments need to be done on an entire population of sockeye salmon with artificially reduced ratios of males to females to determine whether the movements of the spawners would result in an efficiency of egg fertilization sufficient to make harvesting of the "surplus" males feasible.

Download or read book The Freshwater Fishes of Alaska written by James Edwin Morrow and published by . This book was released on 1980 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists all known species.

Download or read book Ecology of Stream dwelling Fishes in Response to Inter annual Variation in the Abundance of Spawning Sockeye Salmon written by Kale T. Bentley and published by . This book was released on 2014 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: Each year, millions of salmon enter the final stage of their life-cycle and migrate back towards their natal watersheds to reproduce. After accumulating >95% of their adult body mass in marine environments, salmon spawning migrations generate massive fluxes of nutrients and energy to inland food webs that can exceed background levels of in situ productivity, and these resources are utilized by a wide range of taxa (Naiman et al. 2002, Gende et al. 2002, Schindler et al. 2003). However, one-half to three-fourths of all returning salmon are harvested by commercial fisheries in coastal oceans prior to reproducing, as salmon fisheries in Alaska are currently managed to maximize the long-term sustainable yield of salmon (Baker et al. 2009). Although this practice is widely touted as a fisheries management success story (Hilborn 2006), people are beginning to ask, what effect does removing the biomass of salmon prior to spawning have on freshwater and terrestrial ecosystems. Thus, there has been a call to shift the paradigm of fisheries management from one that focuses solely on maximizing the yield of single target species to a more holistic approach that accounts for other ecosystem processes (Pikitch et al. 2004, Crowder et al. 2008, Piccolo et al. 2009). In order to develop an ecosystem-based management approach, salmon managers need to be able to assess the trade-offs of different management scenarios that affect how many salmon are harvested versus released to the watershed (known as "escapement") to spawn and benefit inland ecosystems. Currently, assessing these trade-offs is difficult; while there is a well-established theory of how to optimize commercial catch based on stock-recruit relationships (Ricker 1954, Hilborn and Walters 1992, Quinn and Deriso 1999), we lack a quantitative understanding of how the number of salmon returning to spawn influences freshwater and terrestrial ecosystems. The focus of my thesis was to evaluate of the ecological response of Arctic grayling (Thymallus arcticus) and rainbow trout (Oncorhynchus mykiss), two species of resident fish that rely heavily on consumption of salmon resource subsidies (Scheuerell et al. 2007, Moore et al. 2008), to variation in the abundance of adult sockeye salmon (Oncorhynchus nerka) in the Wood River watershed, Bristol Bay, Alaska. The first chapter of my thesis assessed the ability of a body condition index to serve as a proxy for estimating individual instantaneous growth rates as obtaining direct measurements of growth can be time consuming, costly, and logistically impractical. We found that relative body condition of grayling and rainbow trout, as measured by the residuals around a length-mass regression, was strongly correlated with direct measures of individual instantaneous growth from recaptured tagged fish. Using the derived relationship between body condition and growth, we developed a model to estimate growth rates of individual fish based on their observed body condition. Chapter two evaluated the foraging and growth responses of grayling and rainbow trout in two streams that vary in in situ productivity to changes in the abundances of spawning sockeye salmon. Over 11 years, and across a greater than 10-fold variation in density of spawning sockeye salmon, both species of resident fish exhibited a relatively similar, but mechanistically different, saturating growth response to increasing salmon density. This growth response was driven by both an increase in consumption of salmon eggs and also a decrease in dietary overlap between the two species. However, the relative change in growth from low to high salmon densities was different between streams and depended on in situ stream productivity. In low salmon density years the growth of resident consumers fell 46-68% relative to high years in the low productivity stream, but only by 26-34% in the high productivity stream. Growth rates of both consumer species saturated in years when densities of sockeye salmon exceeded about 0.3 - 0.4 m2 on the spawning grounds. Chapter three evaluated the movement patterns of Arctic grayling and rainbow trout within and among streams, which offer patchily distributed foraging opportunities during the summer months. Across both years, approximately 50% of individual grayling and rainbow trout exhibited kilometer-scale movements among two or more streams across the river network within a single summer. Movements were concentrated in June and July, and subsided by early August, coincident with the arrival of spawning sockeye salmon (O. nerka). These inter-stream movements may represent prospecting behavior as individuals seek out the most profitable foraging opportunities. Thus, resident fishes in the Wood River system appear to use the broad network of habitat available to them across the riverscape, rather than depend on individual tributaries for achieving growth. Together the results of this thesis improve our understanding of how inland ecosystem respond to changes in salmon abundance. These results will be of use for resource managers interested in directly evaluating the socio-economic trade-offs of allocating salmon resources among user groups. The results of this work also highlight the importance of maintaining connectivity to enable movements of resident fish across river basins, the ecological consequences of which remain poorly understood.

Download or read book Dissertation Abstracts written by and published by . This book was released on 1963-05 with total page 1756 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstracts of dissertations and monographs in microform.

Download or read book Dictionary Catalog of the Department Library written by United States. Department of the Interior. Library and published by . This book was released on with total page 742 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Behavior and Distribution of Spawning Sockeye Salmon on Island Beaches in Lliamna Lake Alaska 1965 written by Orra Edwin Kerns and published by . This book was released on 1968 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book National Union Catalog written by and published by . This book was released on 1979 with total page 1032 pages. Available in PDF, EPUB and Kindle. Book excerpt: Includes entries for maps and atlases.

Download or read book The Migration and Spawning Distribution of Sockeye Salmon Within Lake Clark Alaska written by Daniel B. Young and published by . This book was released on 2004 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Recent declines in the number of sockeye salmon Onchorynchus nerka returning to Lake Clark, Alaska have caused economic hardship in the region and raised resource concerns among local subsistence users and Federal managers. A lack of information regarding the distribution of spawning habitats in the glacially turbid Lake Clark watershed instigated this research. Radio telemetry was used to 1) determine the in-lake movement patterns of adult sockeye salmon and 2) identify sockeye salmon spawning locations. Sockeye salmon were radio tagged at they entered Lake Clark and tracked to spawning locations. After entering Lake Clark, sockeye salmon usually migrated to a region of the lake that was within 15 km of their spawning location. Tagged fish migrated faster and more directly to spawning locations in tributary rivers and lakes than to Lake Clark beaches. Thirty three spawning locations were identified in the Lake Clark watershed including 18 new spawning locations compared to previous scientific research and ten compared to traditional local knowledge. Most radio tagged sockeye salmon (65%) returned to spawning locations in glacially turbid waters and most spawning locations (75%) were adjacent to privately owned lands. Proactive measures should be taken to conserve both migration corridors and spawning habitats"--Leaves iii.

Download or read book Iowa State College Journal of Science written by and published by . This book was released on 1962 with total page 542 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bibliography of Theses on Fishery Biology written by Sport Fishing Institute and published by . This book was released on 1972 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: