EBookClubs

Read Books & Download eBooks Full Online

EBookClubs

Read Books & Download eBooks Full Online

Book Movements of Spawning Sockeye Salmon in Hidden Creek  Brooks Lake  Alaska

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.

Book Ecological Studies of Sockeye Salmon and Related Limnological and Climatological Investigations  Brooks Lane  Alaska  1957

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:

Book Pacific Salmon Life Histories

Download or read book Pacific Salmon Life Histories written by Cornelis Groot and published by UBC Press. This book was released on 1991 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pacific salmon are an important biological and economic resource of countries of the North Pacific rim. They are also a unique group of fish possessing unusually complex life histories. There are seven species of Pacific salmon, five occurring on both the North American and Asian continents (sockeye, pink, chum, chinook, and coho) and two (masu and amago) only in Asia. The life cycle of the Pacific salmon begins in the autumn when the adult female deposits eggs that are fertilized in gravel beds in rivers or lakes. The young emerge from the gravel the following spring and will either migrate immediately to salt water or spend one or more years in a river or lake before migrating. Migrations in the ocean are extensive during the feeding and growing phase, covering thousands of kilometres. After one or more years the maturing adults find their way back to their home river, returning to their ancestral breeding grounds to spawn. They die after spawning and the eggs in the gravel signify a new cycle. Upon this theme Pacific salmon have developed many variations, both between as well as within species. Pacific Salmon Life Histories provides detailed descriptions of the different life phases through which each of the seven species passes. Each chapter is written by a scientist who has spent years studying and observing a particular species of salmon. Some of the topics covered are geographic distribution, transplants, freshwater life, ocean life, development, growth, feeding, diet, migration, and spawning behaviour. The text is richly supplemented by numerous maps, illustrations, colour plates, and tables and there is a detailed general index, as well as a useful geographical index.

Book Observations of Spawning Behavior and Predation on Sockeye Salmons at Hidden Creek  Katmai National Monument  Alaska  July and August  1961

Download or read book Observations of Spawning Behavior and Predation on Sockeye Salmons at Hidden Creek Katmai National Monument Alaska July and August 1961 written by Milton Bernhard Trautman and published by . This book was released on 1961 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book The Sockeye Salmon  Oncorhynchus Nerka

Download or read book The Sockeye Salmon Oncorhynchus Nerka written by Russell Earle Foerster and published by . This book was released on 1968 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Commercial Fisheries Review

Download or read book Commercial Fisheries Review written by and published by . This book was released on 1963 with total page 788 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Bibliographic Series

Download or read book Bibliographic Series written by and published by . This book was released on 1973 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Theses and Dissertations     Oregon State University

Download or read book Theses and Dissertations Oregon State University written by and published by . This book was released on 1973 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Theses and Dissertations  1966 1970  Oregon State University

Download or read book Theses and Dissertations 1966 1970 Oregon State University written by Margaret Basilia Guss and published by . This book was released on 1973 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Transactions of the American Fisheries Society

Download or read book Transactions of the American Fisheries Society written by American Fisheries Society and published by . This book was released on 1962 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book The Migration and Spawning Distribution of Sockeye Salmon Within Lake Clark  Alaska

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.

Book Proceedings of the American Fisheries Society

Download or read book Proceedings of the American Fisheries Society written by American Fisheries Society and published by . This book was released on 1962 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book The Effects of Spawning Sockeye Salmon  Oncorhynchus Nerka  on Small Streams in the Wood River Lakes  Alaska

Download or read book The Effects of Spawning Sockeye Salmon Oncorhynchus Nerka on Small Streams in the Wood River Lakes Alaska written by Douglas Paul Peterson and published by . This book was released on 1998 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Identification of Spawning Areas and the Influence of Environmental Variation on Freshwater Migration Timing and In river Movements of Adult Coho Salmon in the Buskin River  Alaska

Download or read book Identification of Spawning Areas and the Influence of Environmental Variation on Freshwater Migration Timing and In river Movements of Adult Coho Salmon in the Buskin River Alaska written by Michelle Eileen Stratton and published by . This book was released on 2019 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: The timing of freshwater entry by anadromous salmonids varies markedly among species and populations within species and is frequently used as an indicator of local adaptation to sitespecific patterns of selection. Although complex stock structure is most often associated with large watersheds that have extensive habitat diversity, even small drainages can produce multiple co-occurring stocks that differ in migratory timing. In addition, migration timing can be influenced by within-year environmental conditions experienced by migrating individuals en route to spawning sites, staging near the river mouth in the ocean, or within the river itself. Each stage of migration through both freshwater and saltwater could be altered based on climatic drivers and how each individual fish reacts to these stressors. The objective of this thesis was to assess the potential for stock structure in Coho Salmon within a small coastal watershed on Kodiak Island, Alaska by 1) identifying important differences in spawning and holding locations associated with run timing, length, and stream life between main stem and tributary spawners, 2) quantifying the influence of large-, intermediate-, and local-scale climate variables on freshwater entrance timing and in-river movements. To address the first objective, fish were tracked to their spawning locations using acoustic telemetry in three spawning seasons (2015-2017). I detected no statistically or biologically meaningful differences in body size (length, mm) or migration timing into the river between main stem and tributary spawning fish. Unexpectedly, I found that a large portion of fish (80%) utilize the lake during their in-river migration suggesting the lake may represent critical staging habitat for adult Coho Salmon prior to spawning. I also identified holding habitat throughout the river that both spawning groups consistently used across years that also appears to be important to premature migrating Coho Salmon. In Chapter Two, I analyzed 33 years of freshwater entrance timing data and utilized radio tags to track in-river movement to quantify the influence of precipitation and temperature on total distance moved and probability of moving. Despite marked variation among years, I found no evidence of a temporal trend in entrance timing based on escapement counts, which contrasts with other recent examples throughout Alaska reporting changes in run timing. The strongest influence on timing of freshwater entry was ocean sea surface temperature, where cold temperatures delayed entry up to 11 days. Within-river movements were positively related to precipitation and temperature, confirming local traditional knowledge in this system, and consistent with life history patterns of Coho Salmon. The primary messages of this thesis are that i) any within-watershed stock structure is unlikely to be differentially affected by harvest or management given overlapping run timing, body size, and use of main stem holding areas; future population genetics analyses would be an obvious and illuminating next step to assess the extent to which main stem and tributary spawners are reproductively isolated groups; ii) both main stem and tributary spawners use Buskin Lake as holding habitat prior to spawning, and thus assumptions that fish that enter the upper watershed are destined to spawn in headwater tributaries are invalid, which in turn limits the utility of enumerating adult passage into the lake for escapement-based management, iii) adult freshwater entrance timing is highly variable but not changing systematically through time, though the extent to which the variation in timing reflects environmental response vs. uncertainty in the counts at the weir is unknown, and iv) low precipitation and warm temperatures suppress movement and result in protracted use of main stem and lake habitats for holding, which may put some individuals at risk to angler harvest or, in extreme events, potentially low dissolved oxygen environments. Spatial management that restricts fishing in locations of known primary holding habitats may be an option to reduce probability of mortality and stress in years of low adult abundance.