Author: Jack A. Burgess
Publisher:
ISBN:
Category : Aquatic animals
Languages : en
Pages : 190
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Book Description
Response of aquatic vertebrates to increased pool habitat complexity due to abundance of large wood was evaluated experimentally in three streams in the Cascade Mountains of Oregon. No difference in aquatic vertebrate density was detected among treatments, though there was a trend of increasing aquatic vertebrate density with increasing large wood abundance. The small change in density of aquatic vertebrate species may have been due to the overriding influence of the high habitat heterogeneity associated with cobble/boulder substrate in these streams. Large wood may have a stronger influence in simpler streams with smaller particle size, in differing environmental regimes, or at spatial scales larger than channel unit. Mark-recapture estimates, catchability-based estimates, and maximum likelihood multiple removal estimates were compared in all three streams. Physical heterogeneity influenced efficiency of capture. The single pass catchability-based estimates were larger than mark-recapture estimates and maximum likelihood multiple removal estimates. Mark-recapture estimates were larger than maximum likelihood multiple removal estimates. The mark-recapture method gives more reliable and accurate estimates than maximum likelihood multiple removal method, but both methods may substantially underestimate the population. Taxon, fish length, and habitat variables influenced catchability for the population estimators examined. Probability of capture of vertebrates for the catchability-based estimator consistently decreased with increasing habitat complexity. Understanding factors that affect the accuracy of population estimators and the impact that habitat may have on catchability will assist fisheries scientists and managers in making informed decisions regarding the selection of a population estimation method. Research on habitat restoration and habitat relationships must recognize limitations of population estimators and catchability. Recognition of the limitations of population estimators and catchability should allow resource scientists to design more reliable monitoring and evaluation of habitat restoration projects.
Author: Ben S. Ramirez
Publisher:
ISBN:
Category : Competition (Biology)
Languages : en
Pages : 60
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Book Description
In the Pacific Northwest ecoregion of North America, sculpins represent a major constituent of freshwater assemblages in coastal rivers. Based on their prevalence and abundance, sculpins are likely important ecologically, yet little is known of their interactions with co-occurring species, such as widely studied salmon and trout (salmonines). In this study, I evaluated inter- and intraspecific interactions involving cottids (Cottus sp.) and coastal cutthroat trout (Oncorhynchus clarkii clarkii). I used a response surface experimental design to independently evaluate effects of cutthroat trout and sculpin biomass on growth and behavior. There was evidence of both intra- and interspecific interactions between cutthroat trout and sculpins, but the interactions were asymmetrical with biomass of cutthroat trout driving both intra- and interspecific interactions, whereas sculpins had little influence overall. Cutthroat trout biomass was positively related to conspecific aggressive interactions and negatively related to growth. Sculpin exhibited increased use of cover during the day in response to greater biomass of cutthroat trout, but not sculpin biomass. Nocturnal use of cover by sculpins was unaffected by biomass of either species. This experiment provides insights into the species interactions and the mechanisms that may allow sculpins and salmonines to coexist in nature. As cutthroat trout appear to be superior competitors, coexistence between sculpins and cutthroat trout may depend on some form of refuge, either in the form of in-stream cover or crypsis coupled with diel resource segregation. Cutthroat trout are usually active during the day, indicating that nocturnal foraging by sculpins may in part represent a behavior that minimizes interspecific competition with cutthroat trout.
Author: Edward John Connor
Publisher:
ISBN:
Category :
Languages : en
Pages : 494
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Book Description
Author: Niels C. Leuthold
Publisher:
ISBN:
Category : Pacific giant salamander
Languages : en
Pages : 194
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Book Description
In the Pacific Northwest, multiple studies have found negative effects of timber harvest on stream amphibians, but the results have been highly variable and region-specific. In this collection of studies, I examined the short term effect of timber harvest using a field study, and used lab work to examine a potential mechanism for timber harvest effect. Over the last 30 years forest management practices have changed substantially, yet little work examines how modern forest management relates to the abundance or density of stream amphibians. I examined the influences of contemporary forest practices on Pacific giant salamanders as part of the Hinkle Creek paired watershed study. I used a mark-recapture analysis to estimate Pacific giant salamander density at 100 1-m segments spread throughout the basin and then used extended linear models that accounted for correlation resulting from the repeated surveys at sites across years. Density was positively associated with substrate, negatively associate with upstream area drained, and had a weak positive association with fish density, but I found no evidence of an effect of harvest. A Monte Carlo analysis suggested that our results were not sensitive to missing captures at sites with no captures. Pacific Northwest stream amphibians are often negatively associated with sedimentation, but the mechanism underlying this relationship is not clear. One hypothesized mechanism is that the reduced interstitial space that results from sedimentation increases susceptibility of amphibians to predation. I used laboratory mesocosms to test this hypothesis and examine the response of larval Pacific giant salamanders and tailed frogs to cutthroat trout and adult Pacific giant salamander presence under three different levels of sediment. I found amphibian larvae were more visible as sediment level increased and some evidence that larvae were less visible in the presence of fish. Movement decreased in the presence of cutthroat trout, though for tailed frog larvae this effect was marginally significant (p = 0.066). Larvae did not respond to presence of adult Pacific giant salamanders. These patterns are consistent with the hypothesis that sediment affects larval stream amphibians by increasing vulnerability to predation. While both species of larvae actively sought cover in response to fish, I found little evidence that this behavior mitigates the effects of increasing sediment.
Author: Erica Lyn Bishop
Publisher:
ISBN: 9781267104069
Category : Coarse woody debris
Languages : en
Pages : 192
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Book Description
Despite ongoing research on many aspects of stream morphology and large wood effects on mountain stream channels, there have been no studies that quantify these variables in non-fish-bearing, extreme headwater streams. A recent outbreak of Mountain Pine Beetle (Dendroctonus ponderosae) has led to increased Lodgepole pine (Pinus contorta) mortality in the Western North America This outbreak is expected to increase input of large wood to streams in the next decade. Increased understanding of large wood and sediment interactions in small mountain streams could have broad implications in river restoration and habitat research. This study explores an area of less intensive mountain stream research by quantifying hydrologic and morphologic characteristics and large wood channel interactions in two low-order streams (Deadhorse and Lexen creeks) on the Fraser Experimental Forest, Colorado. The influence that large wood has on the study streams was observed during field investigations of hundreds of log steps, and large wood pieces forming bed, banks, and also acting as an erosional agent in the streams. In contrast to studies of larger systems, the lack of patterns and expected relationships between large wood, channel morphology and sediment storage and transport among the study streams illustrate the extent to which they may be highly influenced by local conditions, including widely variable large wood volumes and channel and valley characteristics, such as slope and valley width, between the reaches. The findings of this research show that results of prior studies in mountain streams and their subsequent generalizations regarding expected channel dynamics, large wood, and sediment characteristics may not be applicable to streams of this size and flow regime.
Author:
Publisher: National Technical Info Svc
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 648
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Book Description
This document is a cooperative effort among fifteen Federal agencies and partners to produce a common reference on stream corridor restoration. It responds to a growing national and international interest in restoring stream corridors.
Author:
Publisher:
ISBN:
Category : Fish habitat improvement
Languages : en
Pages : 342
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Book Description
Author: Michael D. Delong
Publisher: Academic Press
ISBN: 0128188480
Category : Nature
Languages : en
Pages : 1109
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Book Description
Rivers of North America, Second Edition features new updates on rivers included in the first edition, as well as brand new information on additional rivers. This new edition expands the knowledge base, providing readers with a broader comparative approach to understand both the common and distinct attributes of river networks. The first edition addressed the three primary disciplines of river science: hydrology, geomorphology, and ecology. This new edition expands upon the interactive nature of these disciplines, showing how they define the organization of a riverine landscape and its processes. An essential resource for river scientists working in ecology, hydrology, and geomorphology. - Provides a single source of information on North America's major rivers - Features authoritative information on more than 200 rivers from regional specialists - Includes full-color photographs and topographical maps to illustrate the beauty, major features, and uniqueness of each river system - Offers one-page summaries help readers quickly find key statistics and make comparisons among rivers
Author: Charlotte C. Corkran
Publisher: Lone Pine Publishing
ISBN:
Category : Nature
Languages : en
Pages : 180
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Book Description
Amphibians are provided, including: habitat preferences, tips for finding them, planning amphibian surveys, guidelines for handling and measuring them, their activity through the seasons, photography tips, a table that compares confusing species, current status. This handy, informative book is sure to be invaluable to biologists and field technicians as well as to individuals on a family outing or school field trip. Book jacket.
Author: William J. Langston
Publisher: Springer Science & Business Media
ISBN: 1475727615
Category : Science
Languages : en
Pages : 480
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Book Description
Metal Metabolism in Aquatic Environments is a synthesis of recent developments in the field of metal ecotoxicology and features a number of contemporary issues arising from the interaction of metals and biota, such as pathways of assimilation and food chain transfer, metal accumulation and detoxification in humans and biotransformation of elements such as mercury and arsenic.
