Abiotic And Biotic Dimensions Of Habitat For Juvenile Salmon And Other Fishes In The Skeena River Estuary
DOWNLOAD
Download Abiotic And Biotic Dimensions Of Habitat For Juvenile Salmon And Other Fishes In The Skeena River Estuary PDF/ePub or read online books in Mobi eBooks. Click Download or Read Online button to get Abiotic And Biotic Dimensions Of Habitat For Juvenile Salmon And Other Fishes In The Skeena River Estuary book now. This website allows unlimited access to, at the time of writing, more than 1.5 million titles, including hundreds of thousands of titles in various foreign languages. If the content not found or just blank you must refresh this page
Abiotic And Biotic Dimensions Of Habitat For Juvenile Salmon And Other Fishes In The Skeena River Estuary
DOWNLOAD
Author : Ciara Sharpe
language : en
Publisher:
Release Date : 2017
Abiotic And Biotic Dimensions Of Habitat For Juvenile Salmon And Other Fishes In The Skeena River Estuary written by Ciara Sharpe and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2017 with categories.
Estuaries are increasingly degraded globally but provide nursery services for juvenile fishes through predator protection and increased food availability. This thesis examined the abiotic and biotic factors that contributed to abundance patterns of juvenile salmon and forage fish species in the Skeena River estuary, BC. I first showed that spatial abundance patterns were heterogeneous for salmon and that the combination of variables that predicted abundance differed between species. Inclusion of these dynamic abiotic and biotic variables increased predictive power over solely using static habitat descriptors for juvenile salmon. Next, I examined the association between fish and prey abundance for two forage fish and juvenile salmon species. Overall, fish abundance was not related to prey abundance, except for herring which co-varied with a highly consumed prey species. Understanding the factors influencing estuarine habitat use by economically-important juvenile salmon and forage fish can help inform risk assessment and guide environmental planning.
Aspects Of The Early Life History Of Juvenile Salmonids In The Dungeness River Estuary
DOWNLOAD
Author : Nichole K. Sather
language : en
Publisher:
Release Date : 2009
Aspects Of The Early Life History Of Juvenile Salmonids In The Dungeness River Estuary written by Nichole K. Sather and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2009 with Pacific salmon categories.
The decline of many Pacific salmon stocks has stimulated interest in the early life history and habitat requirements of juvenile salmon. Although estuarine habitat associations of juvenile salmon have been investigated in many coastal areas of the eastern Pacific Ocean, until recently, little was known about juvenile salmonid ecology within the Straits of Juan de Fuca. During the Spring/Summer outmigration period in 2006 and 2007, I examined the early life history of the five species of anadromous salmon in the Dungeness River estuary on the north Olympic Peninsula, Washington. I sampled multiple spatial scales within several habitat types to characterize salmon distribution and habitat use. My results presented in this thesis are segregated into two components: 1) tidal marsh ecology of juvenile salmonids in the Dungeness River estuary, and 2) the landscape-scale distribution of juvenile salmonids within the Dungeness River estuary. I examined the population of juvenile salmonids within blind tidal sloughs near the vicinity of the Dungeness River delta. Salmonids were present within the tidal marshes throughout the entire outmigration period (e.g., March through July). Juvenile Chinook salmon (Oncorhynchus tshawytscha) were the most abundant salmonid species within the marshes. Based on the temporal distribution and size structure of juvenile Chinook salmon in the estuary I identified at least four life history types: 1) a fry strategy included a large pulse of fish emigrating from the river at a small size (e.g., 35-45mm FL) during late winter and early spring months; 2) the second group of fish was the least abundant group emigrating from the river from April through mid May at sizes ranging from 50-75mm FL; 3) the third group of migrants entered the estuary between from late spring through the summer months at larger sizes than the initial groups (e.g., 60-90mm FL); and 4) the final group of Chinook salmon included a stream-type yearling strategy. In addition to the four life history strategies identified for Chinook salmon, I detected at least three groups of chum salmon migrating into the estuary. These groups were distinguished by their size and timing of migration and are further described according to different rearing strategies. The distribution of juvenile salmonids was most strongly influenced by the degree of connectivity (i.e., distance) between the tidal marshes and the mouth of the Dungeness River. Habitat complexity and opportunity also governed the distribution of juvenile salmonids within the tidal marshes. I also sampled three regions of the estuary with a beach seine to investigate the nearshore distribution of juvenile salmonids within the Dungeness River estuary: the delta face, inner Bay, and outer Bay. Among the three regions, species composition was highly variable between 2006 and 2007. The most common salmonids encountered within the beach seine sites included Chinook salmon, chum salmon (O. kisutch), and pink salmon (O. gorbuscha). The relative abundance of salmonids was highest near the delta face and lowest within the outer bay area. The landscape-scale distribution and habitat use of juvenile salmonids within the Dungeness River estuary is largely influenced by ecosystem connectivity, but is also linked to biotic characteristics of the fish (e.g., life history type and fish size). Although the Dungeness includes hydrogeomorphic characteristics (e.g., steep river gradient, composition of sand spits in the estuary) unique to other Pacific Northwest watersheds, this system produces a variety of life history types comparable to other estuaries. Understanding the mechanisms that drive the distribution of juvenile salmonids within the Dungeness will supply local resource managers with a baseline with which to establish ecosystem restoration goals.
Juvenile Chinook Salmon Oncorhynchus Tshawytscha Life History Diversity And Growth Variability In A Large Freshwater Tidal Estuary
DOWNLOAD
Author : Pascale A. L. Goertler
language : en
Publisher:
Release Date : 2014
Juvenile Chinook Salmon Oncorhynchus Tshawytscha Life History Diversity And Growth Variability In A Large Freshwater Tidal Estuary written by Pascale A. L. Goertler and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2014 with categories.
For many fish and wildlife species, a mosaic of available habitats is required to complete their life cycle, and is considered necessary to ensure population stability and persistence. Particularly for young animals, nursery habitats provide opportunities for rapid growth and high survival during this vulnerable life stage. My thesis focuses on juvenile Chinook salmon (Oncorhynchus tshawytscha) and their use of estuarine wetlands as nursery habitat. Estuaries are highly productive systems representing a mosaic of habitats connecting rivers to the sea, and freshwater tidal estuaries provide abundant prey communities, shade, refuge from predation and transitional habitat for the osmoregulatory changes experienced by anadromous fishes. I will be discussing the freshwater tidal wetland habitat use of juvenile Chinook salmon in the Columbia River estuary, which are listed under the Endangered Species Act. I used otolith microstructural growth estimates and prey consumption to measure rearing habitat quality. This sampling effort was designed to target as much genetic diversity as possible, and individual assignment to regional stocks of origin was used to describe the diversity of juvenile Chinook salmon groups inhabiting the estuary. Diversity is important for resilience, and in salmon biocomplexity within fish stocks has been shown to ensure collective productivity despite environmental change. However much of the research which links diversity to resilience in salmon has focused on the adult portion of the life cycle and many resource management policies oversimplify juvenile life history diversity. When this oversimplification of juvenile life history diversity is applied to salmon conservation it may be ignoring critical indicators for stability. Therefore in addition to genetic diversity I also explore methods for better defining juvenile life history diversity and its application in salmon management, such as permitting requirements, habitat restoration, hydropower practices and hatchery management. This study addresses how juvenile salmon growth changes among a range of wetland habitats in the freshwater tidal portion of the Columbia River estuary and how growth variation describes and contributes to life history diversity. To do this, I incorporated otolith microstructure, individual assignment to regional stock of origin, GIS habitat mapping and diet composition, in three habitats (mainstem river, tributary confluence and backwater channel) along ~130 km of the upper estuary. For my first chapter I employed a generalized linear model (GLM) to test three hypotheses: juvenile Chinook growth was best explained by (1) temporal factors, (2) habitat use, or (3) demographic characteristics, such as stock of origin or the timing of seaward migration. I found that variation in growth was best explained by habitat type and an interaction between fork length and month of capture. Juvenile Chinook salmon grew faster in backwater channel habitat and later in the summer. I also found that mid-summer and late summer/fall subyearlings had the highest estuarine growth rates. When compared to other studies in the basin these juvenile Chinook grew on average 0.23, 0.11-0.43 mm/d in the freshwater tidal estuary, similar to estimates in the brackish estuary, but ~4 times slower than those in the plume and upstream reservoirs. However, survival studies from the system elucidated a possible tradeoff between growth and survival in the Columbia River basin. These findings present a unique example of the complexity in understanding the influences of the many processes that generate variation in growth rate for juvenile anadromous fish inhabiting estuaries. In my second chapter, I used otolith microstructure and growth trends produced in a dynamic factor analysis (DFA, a multivariate time series method only recently being used in fisheries) to identify the life history variation in juvenile Chinook salmon caught in the Columbia River estuary over a two-year period (2010-2012). I used genetic assignment to stock of origin and capture location and date with growth trajectories, as a proxy for habitat transitions, to reconstruct life history types. DFA estimated four to five growth trends were present in juvenile Chinook salmon caught in the Columbia River estuary, diversity currently being simplified in many management practices. Regional stocks and habitats did not display divergent growth histories, but the marked hatchery fish did ordinate very similarly in the trend loadings from the DFA analysis, suggesting that hatchery fish may not experience the same breadth of growth variability as wild fish. I was not able to quantify juvenile life history diversity, and juvenile Chinook life history diversity remains difficult to catalog and integrate into species conservation and habitat restoration for resource management. However, by expanding our understanding of how juvenile Chinook salmon experience their freshwater rearing environment we improve our capacity to conserve and manage salmon populations. The findings from my thesis provide the necessary information for a restoration framework to link habitat features with salmon management goals, such as juvenile growth, wild and genetic origin and life history diversity.
Historic Habitat Opportunities And Food Web Linkages Of Juvenile Salmon In The Columbia River Estuary Annual Report Of Research
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2009
Historic Habitat Opportunities And Food Web Linkages Of Juvenile Salmon In The Columbia River Estuary Annual Report Of Research written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2009 with categories.
In 2002 with support from the U.S. Army Corps of Engineers (USACE), an interagency research team began investigating salmon life histories and habitat use in the lower Columbia River estuary to fill significant data gaps about the estuary's potential role in salmon decline and recovery . The Bonneville Power Administration (BPA) provided additional funding in 2004 to reconstruct historical changes in estuarine habitat opportunities and food web linkages of Columbia River salmon (Onchorhynchus spp.). Together these studies constitute the estuary's first comprehensive investigation of shallow-water habitats, including selected emergent, forested, and scrub-shrub wetlands. Among other findings, this research documented the importance of wetlands as nursery areas for juvenile salmon; quantified historical changes in the amounts and distributions of diverse habitat types in the lower estuary; documented estuarine residence times, ranging from weeks to months for many juvenile Chinook salmon (O. tshawytscha); and provided new evidence that contemporary salmonid food webs are supported disproportionately by wetland-derived prey resources. The results of these lower-estuary investigations also raised many new questions about habitat functions, historical habitat distributions, and salmon life histories in other areas of the Columbia River estuary that have not been adequately investigated. For example, quantitative estimates of historical habitat changes are available only for the lower 75 km of the estuary, although tidal influence extends 217 km upriver to Bonneville Dam. Because the otolith techniques used to reconstruct salmon life histories rely on detection of a chemical signature (strontium) for salt water, the estuarine residency information we have collected to date applies only to the lower 30 or 35 km of the estuary, where fish first encounter ocean water. We lack information about salmon habitat use, life histories, and growth within the long tidal-fresh reaches of the main-stem river and many tidally-influenced estuary tributaries. Finally, our surveys to date characterize wetland habitats within island complexes distributed in the main channel of the lower estuary. Yet some of the most significant wetland losses have occurred along the estuary's periphery, including shoreline areas and tributary junctions. These habitats may or may not function similarly as the island complexes that we have surveyed to date. In 2007 we initiated a second phase of the BPA estuary study (Phase II) to address specific uncertainties about salmon in tidal-fresh and tributary habitats of the Columbia River estuary. This report summarizes 2007 and 2008 Phase II results and addresses three principal research questions: (1) What was the historic distribution of estuarine and floodplain habitats from Astoria to Bonneville Dam? (2) Do individual patterns of estuarine residency and growth of juvenile Chinook salmon vary among wetland habitat types along the estuarine tidal gradient? (3) Are salmon rearing opportunities and life histories in the restoring wetland landscape of lower Grays River similar to those documented for island complexes of the main-stem estuary? Phase II extended our analysis of historical habitat distribution in the estuary above Rkm 75 to near Bonneville Dam. For this analysis we digitized the original nineteenth-century topographic (T-sheets) and hydrographic (H-sheets) survey maps for the entire estuary. Although all T-sheets (Rkm 0 to Rkm 206) were converted to GIS in 2005 with support for the USACE estuary project, final reconstruction of historical habitats throughout the estuary requires completion of the remaining H-sheet GIS maps above Rkm 75 and their integration with the T-sheets. This report summarizes progress to date on compiling the upper estuary H-sheets above Rkm 75. For the USACE estuary project, we analyzed otoliths from Chinook salmon collected near the estuary mouth in 2003-05 to estimate variability in estuary residence times among juvenile out migrants. In Phase II we expanded these analyses to compare growth and residency among individuals collected in tidal-fresh water wetlands of the lower main-stem estuary. Although no known otolith structural or chemical indicators currently exist to define entry into tidal fresh environments, our previous analyses indicate that otolith barium concentrations frequently increase before individuals encounter salt water. Here we evaluate whether otolith barium levels may provide a valid indicator of tidal fresh water entry by Columbia River Chinook salmon. We also examine otolith growth increments to quantify and compare recent (i.e., the previous 30 d) growth rates among individuals sampled in different wetland habitats along the estuarine tidal gradient.
Estuarine Habitat And Juvenile Salmon
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2011
Estuarine Habitat And Juvenile Salmon written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2011 with Fish populations categories.
Ecology Of Juvenile Salmon In Shallow Tidal Freshwater Habitats In The Vicinity Of The Sandy River Delta Lower Columbia River 2008 Annual Report
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2009
Ecology Of Juvenile Salmon In Shallow Tidal Freshwater Habitats In The Vicinity Of The Sandy River Delta Lower Columbia River 2008 Annual Report written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2009 with categories.
The tidal freshwater monitoring (TFM) project reported herein is part of the research, monitoring, and evaluation effort developed by the Action Agencies (Bonneville Power Administration, the U.S. Army Corps of Engineers [USACE], and the U.S. Bureau of Reclamation) in response to obligations arising from the Endangered Species Act (ESA) as a result of operation of the Federal Columbia River Power System. The project is being performed under the auspices of the Northwest Power and Conservation Council's Columbia Basin Fish and Wildlife Program (Project No. 2005-001-00). The research is a collaborative effort among the Pacific Northwest National Laboratory, the Oregon Department of Fish and Wildlife, the National Marine Fisheries Service, and the University of Washington. The overarching goal of the TFM project is to bridge the gap in knowledge between tidal freshwater habitats and the early life history attributes of migrating salmon. The research questions include: In what types of habitats within the tidal freshwater area of the Columbia River are juvenile salmon found, when are they present, and under what environmental conditions? What is the ecological contribution of shallow (0-5 m) tidal freshwater habitats to the recovery of ESA-listed salmon in the Columbia River basin? Field data collection for the TFM project commenced in June 2007 and since then has continued monthly at six to nine sites in the vicinity of the Sandy River delta (river kilometer 192-208). While this report includes summary data spanning the 19-month period of study from June 2007 through December 2008, it highlights sampling conducted during calendar year 2008. Detailed data for calendar year 2007 were reported previously. The 2008 research objectives were as follows: (1) Characterize the vegetation composition and percent cover, conventional water quality, water surface elevation, substrate composition, bathymetry, and beach slope at the study sites within the vicinity of the Sandy River delta. (2) Characterize the fish community and juvenile salmon migration, including species composition, length-frequency distribution, density (number/m2), and temporal and spatial distributions in the vicinity of the Sandy River delta in the lower Columbia River and estuary (LCRE). (3) Determine the stock of origin for juvenile Chinook salmon (Oncorhynchus tshawytscha) captured at sampling sites through genetic identification. (4) Characterize the diets of juvenile Chinook and coho (O. kisutch) salmon captured within the study area. (5) Estimate run timing, residence times, and migration pathways for acoustic-tagged fish in the study area. (6) Conduct a baseline evaluation of the potential restoration to reconnect the old Sandy River channel with the delta. (7) Apply fish density data to initiate a design for a juvenile salmon monitoring program for beach habitats within the tidal freshwater segment of the LCRE (river kilometer 56-234).
Proceedings Of The National Workshop On Effects Of Habitat Alteration On Salmonid Stocks
DOWNLOAD
Author : Colin D. Levings
language : en
Publisher: Fisheries and Oceans, Communications Directorate
Release Date : 1989
Proceedings Of The National Workshop On Effects Of Habitat Alteration On Salmonid Stocks written by Colin D. Levings and has been published by Fisheries and Oceans, Communications Directorate this book supported file pdf, txt, epub, kindle and other format this book has been release on 1989 with Nature categories.
National workshop convened to review the latest techniques available to quantify relationships between habitat features and fish production. The workshop focused on salmonids because of their importance on both the Atlantic and Pacific coasts, but effects on other non-salmonid populations were included since data is scarce in some areas. Coverage included methodologies for the quantification of the effects of habitat alteration on yield, empirical examples of the effects of physical and chemical habitat changes on stocks, and the permissable degree of extrapolation in assigning effects of habitat alteration to a stock.
An Ecological Comparison Of Juvenile Chum Salmon From Two Watersheds In Norton Sound Alaska
DOWNLOAD
Author : Matthew J. Nemeth
language : en
Publisher:
Release Date : 2006
An Ecological Comparison Of Juvenile Chum Salmon From Two Watersheds In Norton Sound Alaska written by Matthew J. Nemeth and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2006 with Chum salmon categories.
This report describes the use of estuaries by juvenile chum salmon in 2 watersheds that empty into Norton Sound with differing amounts of estuarine habitat. One watershed is the Nome River which has a confined river mouth and has little estuarine habitat. The other watershed is the Eldorado River 10 miles to the east which flows through the Safety Sound estuary and has a greater amount of habitat.
Estuarine Habitat And Juvenile Salmon
DOWNLOAD
Author : George Curtis Roegner
language : en
Publisher:
Release Date : 2004
Estuarine Habitat And Juvenile Salmon written by George Curtis Roegner and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2004 with Fishes categories.
Salmon Life Histories Habitat And Food Webs In The Columbia River Estuary
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2008
Salmon Life Histories Habitat And Food Webs In The Columbia River Estuary written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2008 with categories.
From 2002 through 2006 we investigated historical and contemporary variations in juvenile Chinook salmon Oncorhynchus tshawytscha life histories, habitat associations, and food webs in the lower Columbia River estuary (mouth to rkm 101). At near-shore beach-seining sites in the estuary, Chinook salmon occurred during all months of the year, increasing in abundance from January through late spring or early summer and declining rapidly after July. Recently emerged fry dispersed throughout the estuary in early spring, and fry migrants were abundant in the estuary until April or May each year. Each spring, mean salmon size increased from the tidal freshwater zone to the estuary mouth; this trend may reflect estuarine growth and continued entry of smaller individuals from upriver. Most juvenile Chinook salmon in the mainstem estuary fed actively on adult insects and epibenthic amphipods Americorophium spp. Estimated growth rates of juvenile Chinook salmon derived from otolith analysis averaged 0.5 mm d-1, comparable to rates reported for juvenile salmon Oncorhynchus spp. in other Northwest estuaries. Estuarine salmon collections were composed of representatives from a diversity of evolutionarily significant units (ESUs) from the lower and upper Columbia Basin. Genetic stock groups in the estuary exhibited distinct seasonal and temporal abundance patterns, including a consistent peak in the Spring Creek Fall Chinook group in May, followed by a peak in the Western Cascades Fall Chinook group in July. The structure of acanthocephalan parasite assemblages in juvenile Chinook salmon from the tidal freshwater zone exhibited a consistent transition in June. This may have reflected changes in stock composition and associated habitat use and feeding histories. From March through July, subyearling Chinook salmon were among the most abundant species in all wetland habitat types (emergent, forested, and scrub/shrub) surveyed in the lower 100 km of the estuary. Salmon densities within wetland habitats fell to low levels by July, similar to the pattern observed at mainstem beach-seining sites and coincident with high water temperatures that approached or exceeded 19 C by mid-summer. Wetland habitats were used primarily by small subyearling Chinook salmon, with the smallest size ranges (i.e., rarely exceeding 70 mm by the end of the wetland rearing season) at scrub/shrub forested sites above rkm 50. Wetland sites of all types were utilized by a diversity of genetic stock groups, including less abundant groups such as Interior Summer/Fall Chinook.