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Full-Text Articles in Life Sciences

Evaluating The Utility Of Tracers To Characterize Environmental Dna Transport And Inform Detection Of Fishes In Small Streams, Gavin B. Bandy Jan 2024

Evaluating The Utility Of Tracers To Characterize Environmental Dna Transport And Inform Detection Of Fishes In Small Streams, Gavin B. Bandy

Cal Poly Humboldt theses and projects

This study was motivated by the need to develop a noninvasive and highly sensitive monitoring tool for determining local occupancy of an endangered aquatic species To make inference into the occupancy of fishes within small stream sites, we developed a method to determine whether environmental DNA (eDNA) concentrations from a target species were elevated relative to a tracer, formulated to mimic eDNA and introduced at a single location. We examined patterns in the observed distribution of the tracer to account for the effects of site-specific transport processes and sampling on distributions of naturally occurring eDNA at small spatial scales (400 …


Seasonal Growth, Movement, And Survival Of Juvenile Coho Salmon (Oncorhynchus Kisutch) Utilizing Restored Rearing Habitat, Monica S. Tonty Jan 2023

Seasonal Growth, Movement, And Survival Of Juvenile Coho Salmon (Oncorhynchus Kisutch) Utilizing Restored Rearing Habitat, Monica S. Tonty

Cal Poly Humboldt theses and projects

The Scott River supports the most robust population of threatened Coho Salmon Oncorhynchus kisutch remaining in the Klamath River basin. Even in the Scott River, low quality and restricted extent of juvenile rearing habitat limits the Coho Salmon population to a small fraction of historic abundance. To support persistence and recovery of Scott River Coho Salmon, the Scott River Watershed Council (SRWC) has constructed a portfolio of restoration projects to improve juvenile rearing habitat, including beaver dam analogs (BDAs). The Scott River BDAs were the first implemented anywhere in California. This study compares juvenile Coho Salmon responses associated with production …


A Time- And State-Based Approach To Estimate Winter Movement And Survival Of Juvenile Coho Salmon (Oncorhynchus Kisutch) In Freshwater Creek, California, Nicholas Paul Van Vleet Jan 2019

A Time- And State-Based Approach To Estimate Winter Movement And Survival Of Juvenile Coho Salmon (Oncorhynchus Kisutch) In Freshwater Creek, California, Nicholas Paul Van Vleet

Cal Poly Humboldt theses and projects

Accounting for life history diversity and overwinter survival of juvenile Coho Salmon is important to inform restoration and recovery efforts for this threatened species. Multiple seaward migration patterns of Coho Salmon have been identified, including spring fry migrants, fall and winter parr migrants, and spring smolt migrants. Previous studies have indicated that spring smolt migrants have low overwinter survival rates while they are rearing in upstream habitats, suggesting that freshwater overwinter survival may be one factor that limits smolt production. However, previous research did not account for the early emigration of fall and winter parr migrants from the study area, …


Freshwater And Marine Survival Of Coho Salmon (Oncorhynchus Kisutch) As A Function Of Juvenile Life History, Grace Katherine Ghrist Jan 2019

Freshwater And Marine Survival Of Coho Salmon (Oncorhynchus Kisutch) As A Function Of Juvenile Life History, Grace Katherine Ghrist

Cal Poly Humboldt theses and projects

Juvenile Coho Salmon (Oncorhynchus kisutch) in coastal California streams exhibit various life history strategies during their freshwater development. One strategy of interest to managers and conservationists is the early migrant. Juvenile early migrants emigrate from natal habitat into lower parts of the watershed or estuary during their first fall or winter, where they rear before migration to the ocean. By contrast, the more prevalent spring migrant resides in natal reaches over the winter and migrates directly to the ocean the following spring. Salmon monitoring programs generally estimate juvenile production and demographic rates using only spring migrants, and these …


Overwinter Survival And Movement Of Juvenile Coho Salmon (Oncorhynchus Kisutch) In Relation To Large Woody Debris And Low-Velocity Habitat In Northern California Streams, John D. Deibner-Hanson Jan 2019

Overwinter Survival And Movement Of Juvenile Coho Salmon (Oncorhynchus Kisutch) In Relation To Large Woody Debris And Low-Velocity Habitat In Northern California Streams, John D. Deibner-Hanson

Cal Poly Humboldt theses and projects

Some studies suggest that Coho Salmon populations are limited by overwinter survival as a result of insufficient winter habitat. While many small-scale projects aim to define reach and basin-level habitat requirements for Coho Salmon, large-scale studies that assess multiple independent populations remain few. For my research, I quantified large woody debris (LWD) by volume and low-velocity rearing habitat (LVH) as percent area in three coastal watersheds of similar size in northern California to untangle the relationships between Coho Salmon overwinter survival, emigration timing and specific winter habitats. I used mark-recapture techniques with PIT tags to formulate Cormack-Jolly-Seber models for each …


Evaluation Of Parameter Estimation And Field Application Of Transgenerational Genetic Mark-Recapture, Ryan W. Whitmore Jan 2016

Evaluation Of Parameter Estimation And Field Application Of Transgenerational Genetic Mark-Recapture, Ryan W. Whitmore

Cal Poly Humboldt theses and projects

Use of a genetic-based analogue of the traditional mark-recapture method (transgenerational genetic mark-recapture, tGMR) is rapidly expanding as a means to estimate total escapement of Pacific salmon. The tGMR approach is similar to the simple Lincoln-Peterson mark-recapture method. In tGMR, adults returning to fresh water to spawn are collected in the first sampling occasion and their juvenile offspring that are migrating out to sea are collected during the second sampling occasion. Recaptures are determined by the number of parent-offspring pairs identified through genetic parentage analysis of the adult and juvenile collections. Two versions of tGMR are currently in use, referred …