Cortisol-induced changes in oxygen consumption and ionic regulation in coastal cutthroat trout (Oncorhynchus clarki clarki) parr

1996 ◽  
Vol 15 (5) ◽  
pp. 385-394 ◽  
Author(s):  
John D. Morgan ◽  
George K. Iwama
Keyword(s):  
Oxygen Consumption ◽  
Cutthroat Trout ◽  
Oncorhynchus Clarki ◽  
Ionic Regulation ◽  
Oncorhynchus Clarki Clarki ◽  
Coastal Cutthroat Trout ◽  
Induced Changes

scholarly journals Genetic composition and conservation status of coastal cutthroat trout (Oncorhynchus clarki clarki) in the San Juan Islands, Washington

2019 ◽  
Vol 21 (1) ◽  
pp. 181-186
Author(s):  
Jamie Glasgow ◽  
Jennifer D. De Groot ◽  
Maureen P. Small
Keyword(s):  
Anthropogenic Impacts ◽  
Conservation Status ◽  
Cutthroat Trout ◽  
Fish Populations ◽  
Oncorhynchus Clarki ◽  
San Juan ◽  
Limited Information ◽  
San Juan Islands ◽  
Oncorhynchus Clarki Clarki ◽  
Coastal Cutthroat Trout

AbstractUnderstanding the conservation status of native fish populations is increasingly important because they are put at risk by mounting anthropogenic pressures, including climate change. Conventional approaches to assess fish populations can be logistically challenging and cost-prohibitive. As a result, resource managers often make assumptions about the status of fish populations based on limited information. The watersheds of Washington’s San Juan Islands were considered too small to support wild salmonid populations. Many streams flow only seasonally, and all have been subjected to varying degrees of anthropogenic impacts affecting their ecological integrity. Nonetheless, we found that at least five watersheds in the archipelago support populations of coastal cutthroat trout (Oncorhynchus clarki clarki). To better understand the conservation status of coastal cutthroat trout populations there, we genotyped approximately fifty trout in each of three watersheds: Cascade and Doe Bay creeks on Orcas Island and Garrison Creek on San Juan Island. Results suggest that two watersheds support native populations and one supports naturalized hatchery fish. The likely native coastal cutthroat trout diversity documented in the two watersheds contributes to the overall diversity of the species, demonstrates that species’ resiliency, and provides justification for conservation measures. Effective management and conservation planning in data-limited situations requires the use of a precautionary approach. Population genetics provide a useful tool for identifying vulnerable fish populations and understanding their relationships with other conspecific populations. This information can inform restoration goals and help identify and prioritize restoration and protection measures.

Early survival and development of coastal cutthroat trout (Oncorhynchus clarki clarki), steelhead (Oncorhynchus mykiss), and reciprocal hybrids

1998 ◽  
Vol 55 (9) ◽  
pp. 2097-2104 ◽  
Author(s):  
Denise K Hawkins ◽  
Chris J Foote
Keyword(s):  
Cutthroat Trout ◽  
Fertilization Success ◽  
Survival Duration ◽  
Oncorhynchus Clarki ◽  
Reciprocal Hybrids ◽  
Oncorhynchus Clarki Clarki ◽  
Coastal Cutthroat Trout ◽  
Survival And Development ◽  
Yolk Absorption ◽  
Two Populations

We compared the survival and development of embryos from fertilization to emergence of two populations of coastal cutthroat trout (Oncorhynchus clarki clarki), one population of steelhead (Oncorhymchus mykiss), and their reciprocal hybrids under controlled conditions (10 ± 1°C). The egg weight of the steelhead (0.110 ± 0.008 (SE) g) was nearly twice that of coastal cutthroat trout (0.056 ± 0.003 and 0.051 ± 0.001 g for the two populations). Fertilization success, survival, duration of hatching and emergence periods, yolk absorption relative to total alevin weight, and yolk conversion efficiency were similar among the cross types. There was no evidence of reduced hatchability or viability of hybrids despite maternal and paternal species effects on size and development. Fish with cutthroat dams had lower percent hatch, were smaller at hatch and emergence, grew more slowly, used less yolk per day, reached 50% yolk absorption earlier, and had a smaller percent yolk at hatch than those fish with steelhead dams. Fish sired by cutthroat males hatched and emerged earlier and took less time between the two stages than fish sired by steelhead. As a consequence, hybrids with cutthroat dams emerged late and had little yolk, while hybrids with steelhead dams emerged early and had an abundance of yolk.

Influence of large woody debris on retention, immigration, and growth of coastal cutthroat trout (Oncorhynchus clarki clarki) in stream pools

1998 ◽  
Vol 55 (8) ◽  
pp. 1902-1908 ◽  
Author(s):  
Bret C Harvey
Keyword(s):  
Woody Debris ◽  
Cutthroat Trout ◽  
Second Order ◽  
Large Woody Debris ◽  
Anadromous Fish ◽  
Oncorhynchus Clarki ◽  
Third Order ◽  
The Third ◽  
Oncorhynchus Clarki Clarki ◽  
Coastal Cutthroat Trout

Over 4 months and about 1 year, coastal cutthroat trout (Oncorhynchus clarki clarki) age-1 in Little Jones Creek, California, remained at similar rates in pools with and without large woody debris. This result was based on attempts in July and November 1995 to collect and tag all fish in 22 pools and three collections of fish from the same pools in November 1995, May 1996, and August 1996. Retention of fish appeared to be greater in pools with large woody debris in May 1996. The presence of large woody debris in pools did not influence immigration or growth of cutthroat trout. However, both immigration and growth increased downstream over the 3850-m study reach. Low retention and substantial immigration of cutthroat trout into experimental pools indicate that movement is important in the dynamics of this population. First- and second-order channels appear to be important sources of fish for the third-order study reach, while the study reach may export significant numbers of fish to downstream reaches accessible to anadromous fish.

Changing patterns in coastal cutthroat trout (Oncorhynchus clarki clarki) diet and prey in a gradient of deciduous canopies

2005 ◽  
Vol 62 (8) ◽  
pp. 1797-1807 ◽  
Author(s):  
Nicolas Romero ◽  
Robert E Gresswell ◽  
Judith L Li
Keyword(s):  
Riparian Vegetation ◽  
Cutthroat Trout ◽  
Unintended Consequences ◽  
Gut Contents ◽  
Invertebrate Drift ◽  
Oncorhynchus Clarki ◽  
Shrub Cover ◽  
Oncorhynchus Clarki Clarki ◽  
Coastal Cutthroat Trout ◽  
Invertebrate Biomass

We examined the influence of riparian vegetation patterns on coastal cutthroat trout Oncorhynchus clarki clarki diet and prey from the summer of 2001 through the spring of 2002. Benthic and drifting invertebrates, allochthonous prey, and fish diet were collected from deciduous, conifer, and mixed sections of three Oregon coastal watersheds. The nine sites were best characterized as a continuum of deciduous cover, and shrub cover and proportion of deciduous canopy were positively correlated (r = 0.74). Most sources of prey (benthic invertebrate biomass, allochthonous invertebrate inputs, aquatic and total invertebrate drift) and aquatic prey ingested by coastal cutthroat trout were greater where shrub cover was more abundant. Only aquatic drift, total invertebrate drift, and allochthonous invertebrates were positively correlated with deciduous vegetation. Compared with coniferous sites, allochthonous invertebrates under deciduous and mixed canopies were almost 30% more abundant. Stream discharge likely influenced seasonal fluxes of aquatic invertebrate biomass in the benthos and drift. Aquatic insects dominated gut contents during this study; however, terrestrial prey were most common in the diet during the summer and fall. In the Pacific northwest, systematic removal of deciduous riparian vegetation to promote conifers may have unintended consequences on food resources of coastal cutthroat trout and aquatic food web interactions.

Effects of an increase in large wood on abundance and survival of juvenile salmonids (Oncorhynchus spp.) in an Oregon coastal stream

2005 ◽  
Vol 62 (2) ◽  
pp. 412-424 ◽  
Author(s):  
Steven L Johnson ◽  
Jeffrey D Rodgers ◽  
Mario F Solazzi ◽  
Thomas E Nickelson
Keyword(s):  
Habitat Restoration ◽  
Coho Salmon ◽  
Cutthroat Trout ◽  
Time Frame ◽  
Oncorhynchus Clarki ◽  
Large Wood ◽  
Winter Storm ◽  
Oncorhynchus Clarki Clarki ◽  
Coastal Cutthroat Trout ◽  
Reference Stream

We examined the effect of an increase in large wood on the summer population size, smolt abundance, and freshwater survival of steelhead (Oncorhynchus mykiss), coastal cutthroat trout (Oncorhynchus clarki clarki), and coho salmon (Oncorhynchus kisutch). We examined these parameters for five brood years prior to the addition of wood and five brood years after in Tenmile Creek, a direct ocean tributary on the Oregon coast. Over the same time frame, a nearby reference stream, Cummins Creek, was also sampled for the same parameters. The input of large wood into Tenmile Creek resulted from a planned habitat restoration project in 1996 and an unplanned addition of wood from a winter storm the same year. Steelhead smolt abundance, steelhead freshwater survival, and coho salmon freshwater survival increased in Tenmile Creek after the input of large wood. Steelhead age-0+ summer populations and steelhead smolt populations increased in the reference stream, although steelhead freshwater survival did not. Coho salmon populations remained unchanged in the reference stream. Our results illustrate the potential shortcomings of the before-after-control-impact study design under field conditions and the potential for misinterpreting results had we employed a more modest sampling plan.

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