The Influence of Habitat Characteristics on Abundance and Growth of Juvenile Coho Salmon Oncorhynchus Kisutch in Constructed Habitats in the Middle Klamath River Basin PDF Download
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Author: Michelle R. Krall
Publisher:
ISBN:
Category : Coho salmon
Languages : en
Pages : 80
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Book Description
Substantial investment has been directed toward construction of off-channel ponds in the middle Klamath River basin to benefit Coho Salmon populations. Previous research showed that abundance, retention, and growth of juvenile Coho Salmon varied across sites but were not consistently different between constructed ponds and natural habitats; instead, variation was attributed to individual site characteristics. However, the characteristics responsible for these differences are not clear. In this exploratory study, I investigated the effect of accessibility on juvenile Coho Salmon abundance within nine constructed ponds. I also assessed whether habitat conditions, Coho Salmon density, and food availability within the ponds could predict abundance, retention, and growth of Coho Salmon. Few strong relationships were found between characteristics of ponds and the response variables. Despite potentially stressful conditions at some sites, Coho Salmon occupied most ponds through the summer, suggesting that they provide suitable rearing habitats. Lack of accessibility throughout the year had potentially important effects on the survival and life history of individuals trapped in constructed ponds. Retention rates were strongly correlated with zooplankton availability, while Coho Salmon density and available benthic prey displayed little correlation with retention. While growth rate differed among ponds; while measures of prey availability did not explain variation in growth rate, growth rate was negatively correlated with Coho Salmon density in the ponds. Constructed off-channel ponds serve as important rearing habitat for Coho Salmon and an increased understanding of their role in Coho Salmon rearing and production is necessary.
Author: Michelle R. Krall
Publisher:
ISBN:
Category : Coho salmon
Languages : en
Pages : 80
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Book Description
Substantial investment has been directed toward construction of off-channel ponds in the middle Klamath River basin to benefit Coho Salmon populations. Previous research showed that abundance, retention, and growth of juvenile Coho Salmon varied across sites but were not consistently different between constructed ponds and natural habitats; instead, variation was attributed to individual site characteristics. However, the characteristics responsible for these differences are not clear. In this exploratory study, I investigated the effect of accessibility on juvenile Coho Salmon abundance within nine constructed ponds. I also assessed whether habitat conditions, Coho Salmon density, and food availability within the ponds could predict abundance, retention, and growth of Coho Salmon. Few strong relationships were found between characteristics of ponds and the response variables. Despite potentially stressful conditions at some sites, Coho Salmon occupied most ponds through the summer, suggesting that they provide suitable rearing habitats. Lack of accessibility throughout the year had potentially important effects on the survival and life history of individuals trapped in constructed ponds. Retention rates were strongly correlated with zooplankton availability, while Coho Salmon density and available benthic prey displayed little correlation with retention. While growth rate differed among ponds; while measures of prey availability did not explain variation in growth rate, growth rate was negatively correlated with Coho Salmon density in the ponds. Constructed off-channel ponds serve as important rearing habitat for Coho Salmon and an increased understanding of their role in Coho Salmon rearing and production is necessary.
Author: Shari K. Witmore
Publisher:
ISBN:
Category : Coho salmon
Languages : en
Pages : 150
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Book Description
Retention rate was positively correlated with average maximum depth; however the summer retention rate of juvenile salmon at the sites was not correlated with salmon growth at the sites. I observed three seasonal movement patterns of juvenile coho salmon: spring redistribution of fry; fall redistribution associated with initial high flows, and outmigration of smolts during the following spring. A diurnal movement pattern was also detected at the mouths of Tom Martin Creek and Caltrans Pond in which juvenile coho salmon left the study site in the evening and returned in the early morning. This exploratory study showed that not only do juvenile coho salmon in the mid-Klamath display several different migratory patterns; choosing different types of off-channel habitats to rear, but the growth and retention rates of those fish depend on complex and site specific characteristics rather than type of habitat.
Author: Paul M. Iwanaga
Publisher:
ISBN:
Category : Fishes
Languages : en
Pages : 52
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Book Description
Author: Gordon H. Reeves
Publisher:
ISBN:
Category : Coho salmon
Languages : en
Pages : 24
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Author:
Publisher:
ISBN:
Category : Coho salmon
Languages : en
Pages : 124
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Coho salmon (Oncorhynchus kisutch) rely on unique habitats during the winter season, which may dictate how much individuals may growth and when migration from freshwater rearing habitat to the ocean occurs. Here I analyze movement timing and growth patterns for coho salmon through a field-based study and a literature review. For the field portion, I examined hatchery-stocked juvenile coho salmon across four stream basins in the Russian River watershed, California to determine the relative importance of climate, landscape, and fish size metrics in predicting movement and growth patterns over a winter rearing and spring smolt outmigration time period (December 2014-June 2015). I observed three unique movement strategies: winter parr movement, spring smolt movement, and inter-tributary movement. Movement was predicted in relation to daily temperature and precipitation, followed by in-stream and upslope basin conditions in random forest modeling. Specifically, fish that moved later were associated with basins that contained higher productivity and low-gradient floodplain habitats, while fish that moved earlier came from streams that lacked invertebrate prey and had limited low-gradient rearing habitat. Fish size and timing of movement were the primary predictors of growth, with relatively larger fish in the spring growing faster than fish that were relatively smaller prior to winter. These relationships suggest that hatchery-release fish are still highly influenced by environmental conditions once released, especially in terms of initial seasonal movement, and that watershed conditions should be considered when utilizing hatchery-rearing programs to supplement wild fish populations. In North America, coho salmon populations are distributed from Alaska through California, and may exhibit unique movement and growth patterns in relationship to population-scale vulnerability (Endangered Species Act listing), basin area, and availability and types of rearing habitat. For the second part of my thesis, I conducted a literature review to assess what factors are commonly considered in predicting movement and growth patterns for these fish, as well as the types (season and life stage) and number of movement strategies reported. Eighteen studies were summarized, of which sixteen identified unique movement strategies, ranging from one to four. Despite a wide range of basin areas and latitudes, winter parr and spring smolt movements were commonly observed, with authors primarily relating these behaviors to in-stream habitat and fish size metrics. Additionally, growth was linked positively and primarily with off-channel winter rearing, which may outweigh the importance of fish size in predicting growth when high quality rearing habitats are available during the winter season. Recognizing movement timing diversity and its drivers can help recover threatened coho salmon populations. More widely distributed populations may have unique phenotypic expressions based on localized genetic and environmental interactions, increasing diversity and overall stability across the population, a concept known as the portfolio effect. Understanding fish-habitat relationships can aid recovery efforts by providing a framework of climatic and watershed conditions that support unique behaviors, even in already severely limited populations.
Author: Kailan F. Mackereth
Publisher:
ISBN:
Category : Coho salmon
Languages : en
Pages : 44
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Book Description
Loss of lowland estuarine and freshwater off-channel habitats along the Pacific Northwest coast has contributed to the decline of salmonid populations. These habitats serve as nursery grounds for juvenile salmonids providing them with food, winter shelter, and a transition zone between freshwater and saltwater. Lowland areas have undergone anthropogenic alterations (e.g., installation of tide gates, construction of dikes, channelization) to increase the net area of land suitable for agriculture and development resulting in watershed fragmentation and reduction in the amount of habitats with high intrinsic potential to support populations of juvenile salmonids. Until recent years, sub-yearling coho salmon found in lowland riverine habitats and estuarine marshes were assumed to have been displaced from optimal upland reaches by competition and high water discharge. Recent studies have concluded that early estuarine migrant behavior is volitional and these fish return as 20-40% of the spawning population, but there are few studies that delve into the capacity of estuarine habitat to support early estuarine life history strategies in systems heavily altered by human practices. This study documented differences in diet and condition factor (K) between sub-yearling and yearling coho salmon foraging concurrently in brackish or freshwater lowland habitat of the upper estuarine intertidal zone. Fish stomach contents were sampled by means of gastric lavage in three coastal lowland creeks in Coos Bay on the southern Oregon coast. Prey found in the samples were sorted, counted, identified, and dried to obtain dry weight biomass. Condition factor (K) and total dry weight prey biomass of fishes were not different between brackish and freshwater habitat; however, non-metric multidimensional scaling indicated that prey composition was substantially different between habitat and age class. These findings suggest that early migrating sub-yearlings and yearling smolts diverge in their diets whether they occupy the same or different habitats in the stream to estuary transition zone. Insects were important prey within the diets of yearling and sub-yearling freshwater foragers and sub-yearling brackish water foragers while crustaceans were important in the diets of yearling brackish water foragers. Future research exploring prey abundance and availability in relation to prey selected by juvenile coho salmon would denote habitat foraging quality and habitat exploitation by early estuarine migrants. Expanding this research to contrast natural intertidal habitats with those regulated by tide gates would be beneficial towards understanding the impact different styles of tide gates have on biotic communities and hydrological attributes (e.g., flow, chemistry, temperature, tidal exchange). Identification of factors that influence habitat selection in the stream-estuary ecotone by alternative early life history strategies of juvenile coho salmon is essential towards enhancing genetic diversity thereby strengthening the resiliency of the population.
Author: Kevin Michael Foley
Publisher:
ISBN:
Category : Coho salmon
Languages : en
Pages : 286
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Understanding how headwater streams function as rearing habitats for juvenile coho salmon Oncorhynchus kisutch is essential for effective population management and conservation. To inform habitat restoration activities within the Matanuska-Susitna Valley, Alaska, I determined upstream distribution limits, validated abundance estimates, and established fish habitat relationships in two headwater stream tributaries of the Little Susitna River in 2010-11. Using a low-effort, spatially continuous sampling approach and linear mixed-effects models, I related local- and landscape-scale habitat associations to abundance estimates. All-aged coho salmon composed approximately 98% of all fish sampled and inhabited the entire stream length to their upstream limits. Age-1+ fish resided in 64% and 44% of the stream length for the two sampled streams. The mean upstream elevation limit for all-aged fish in these streams was 278m and 267m. For age- 1+ fish, the upstream elevation limit in the two streams was 275m and 238m. Percent slope at the distribution limit of all-aged fish was consistent across streams at 5%, whereas percent slope for age-1+ fish correspond to 4% and 6%. Elevation and percent slope consistently described upstream distribution limits among age classes. Therefore, we must consider these landscape features when prioritizing restoration projects in headwater streams.
Author: Thomas E. McMahon
Publisher:
ISBN:
Category : Coho salmon
Languages : en
Pages : 40
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Author: Molly Gorman
Publisher:
ISBN:
Category : Coho salmon
Languages : en
Pages : 79
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The Scott and Shasta rivers, Klamath River tributaries, experience spatial disparity in habitat quality in spring and summer as a result of historical and current land-use. Juvenile Coho Salmon (Oncorhynchus kisutch) born in the upper tributary reaches often rear in natal streams before migrating to sea. However, those born in the lower reaches often encounter unsuitable habitat and emigrate during their first spring to seek non-natal rearing habitats. It is assumed that these early outmigrants are population losses. This study evaluated first-summer survival, and contribution to the adult population, of non-natal rearing juveniles in the Klamath River Basin. In the spring of 2014 and 2015 juveniles were tagged using Passive Integrated Transponder (PIT) tags as they were leaving the lower Scott and Shasta Rivers. Movement and survival was subsequently tracked using recapture and detection efforts in potential mainstem summer rearing locations. Strontium microchemistry from otolith samples of returning adult Coho Salmon throughout the basin was analyzed to estimate the contribution of non-natal rearing juveniles to adult returns. Few tagged individuals were detected in non-natal rearing habitats, but those detected in these habitats had survival rates comparable to natal-rearing individuals. Otolith analysis indicated that the proportion of juvenile Coho Salmon rearing in non-natal habitats varied by spawning site. In total, 53% of the 116 adults sampled reared in a natal location as juveniles, while 47% reared in a non-natal location. These results suggest that non-natal rearing can contribute to adult returns and could be a significant population segment with increased restoration.
Author: Mason D. Bryant
Publisher:
ISBN:
Category : Coho salmon
Languages : en
Pages : 88
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We describe a protocol to monitor the effectiveness of the Tongass Land Management Plan (TLMP) management standards for maintaining fish habitat. The protocol uses juvenile coho salmon (Oncorhynchus kisutch) in small tributary streams in forested watersheds. We used a 3-year pilot study to develop detailed methods to estimate juvenile salmonid populations, measure habitat, and quantitatively determine trends in juvenile coho salmon abundance over 10 years. Coho salmon have been shown to be sensitive to habitat alterations, and we use coho salmon parr as the primary indicator in the protocol. A priori criteria for type I and type II error rates, effect size, and sample sizes for the protocol were derived with estimates of variance computed from the 3-year pilot study. The protocol is designed to detect trends in abundance of coho salmon parr, as well as coho salmon fry and Dolly Varden (Salvelinus malma), in small streams managed according to TLMP standards and guidelines and to compare these to trends in unmanaged (old-growth) watersheds. Trends are adjusted to account for statistically significant habitat covariates. This information provides an important element in monitoring land management practices in the Tongass National Forest. The methods we describe may have application to monitoring protocols elsewhere for fish populations and land management practices.
