scholarly journals Beyond Redistribution: In‐Stream Habitat Restoration Increases Capacity for Young‐of‐the‐Year Chinook Salmon and Steelhead in the Entiat River, Washington

2020 ◽  
Vol 40 (2) ◽  
pp. 446-458 ◽  
Author(s):  
Carlos M. Polivka ◽  
Shannon M. Claeson
Keyword(s):  
Chinook Salmon ◽  
Habitat Restoration ◽  
Stream Habitat ◽  
Young Of The Year

scholarly journals Beyond redistribution: In-stream habitat restoration increases capacity for young-of-the-year Chinook salmon and steelhead in the Entiat River, WA

2019 ◽  
Author(s):  
Carlos M. Polivka ◽  
Shannon M. Claeson
Keyword(s):  
Chinook Salmon ◽  
Habitat Restoration ◽  
Fish Habitat ◽  
Stream Habitat ◽  
Computational Statistics ◽  
Modal Density ◽  
Unit Scale ◽  
Field Methodology ◽  
Young Of The Year ◽  
Bayesian Generalized Linear Model

AbstractWe conducted snorkel surveys for juvenile salmonids in reaches of the Entiat River (Washington, USA) treated with engineered log jams (ELJs), and in reaches without treatments, to determine if habitat-unit-scale observations can identify whether restoration has increased the habitat capacity of a reach. The conceptual basis and field methodology emphasize fish density data (fish/habitat area in m2) from unrestored habitat within a reach treated with ELJs compared to surveys in 1) unrestored habitat in untreated reaches and 2) restored habitat in treated reaches. A Bayesian generalized linear model enabled us to quantify density differences among habitat types using advanced computational statistics. Modal density of young-of-the-year Chinook salmon (Oncorhynchus tschawytscha) and steelhead (O. mykiss) was at least 3.1-fold and 2.7-fold greater, respectively, in restored habitat compared with unrestored habitat for all treated reaches examined. To distinguish the density differences in those reaches as capacity increases rather than redistribution from poor habitat to good habitat, we compared density in unrestored habitat in both treated and untreated reaches. Here we found no differences for either species, confirming that the increased density in restored habitat units did not come from depletion of unrestored habitat in the same reach. We thus concluded that restoration increased the habitat capacity of the reach at the scale of pools created by ELJs.

scholarly journals Ancient DNA Analysis of Archaeological Specimens Extends Chinook Salmon’s Known Historic Range to San Francisco Bay and Its Southernmost Watershed

2020 ◽  
Author(s):  
Richard B. Lanman ◽  
Linda Hylkema ◽  
Cristie M. Boone ◽  
Brian Alleé ◽  
Roger O. Castillo ◽  
...  
Keyword(s):  
Native American ◽  
San Francisco ◽  
Ancient Dna ◽  
Chinook Salmon ◽  
Habitat Restoration ◽  
Dna Analysis ◽  
Oncorhynchus Tshawytscha ◽  
San Francisco Bay ◽  
Bay Area ◽  
Guadalupe River

Understanding a species’ historic range guides contemporary management and habitat restoration. Chinook salmon ( Oncorhynchus tshawytscha ) are an important commercial and recreational gamefish, but nine Chinook subspecies are federally threatened or endangered due to anthropomorphic impacts. Several San Francisco Bay Area streams and rivers currently host spawning Chinook populations, but government agencies consider these non-native hatchery strays. Using ichthyofaunal analysis of 17,288 fish specimens excavated from Native American middens at Mission Santa Clara circa 1781-1834 CE, 86 salmonid vertebrae were identified. Ancient DNA sequencing identified three of these as from Chinook salmon and the remainder from steelhead trout. These findings comprise the first physical evidence of the nativity of salmon to the Guadalupe River in San Jose, California, extending their historic range to include San Francisco Bay’s southernmost watershed.

Biology, Management, and Protection of North American Sturgeon

2002 ◽  
Keyword(s):  
Population Growth ◽  
Life Histories ◽  
Habitat Restoration ◽  
Negative Impact ◽  
Elasticity Analysis ◽  
Age Classes ◽  
Adult Age ◽  
Significant Negative Impact ◽  
Young Of The Year ◽  
Restoration Strategies

Abstract.— We use elasticity analyses for three sturgeon species, the shortnose sturgeon <em>Acipenser brevirostrum</em>, Atlantic sturgeon <em>A. oxyrinchus</em>, and white sturgeon <em>A. transmontanus</em>, to calculate the potential to increase population growth rate, λ, by improving survival and fecundity. Elasticity analysis is a means of assessing changes to λ resulting from conservation initiatives. The elasticity of λ to survival has a characteristic profile that includes a plateau of high elasticity values across the young of the year and the juvenile ages. However, survival elasticity falls at maturity and declines rapidly with increasing adult age. Changes to fecundity have relatively little impact; the total of the fecundity elasticities over all ages is equal to the single young-of-the-year survival elasticity. Even though the young-of-the-year survival elasticity is equal to that of any other juvenile age, the overall opportunity for affecting λ; is strongest in the young-of-the-year age-class because of its exceptional potential for increase to survival. The juvenile and adult stages have roughly equal total survival elasticities. These findings are particularly relevant in understanding the contributions of hatcheries, harvest regulations and habitat restoration as strategies for sturgeon conservation. Hatcheries are focused on the young of the year, the demographically most sensitive component of sturgeon life histories, and thus have the potential to make significant increases to λ if the genetic, evolutionary and ecological impacts of hatcheries can be controlled. Harvest, even at low levels, can have a significant negative impact on λ when it affects multiple age classes. Managers can use elasticity analysis to calculate the total impact of harvest and to mathematically evaluate the trade-off in exploiting young versus older individuals. Habitat restoration strategies, usually assessed in terms of survivals of the age classes impacted, would also benefit from using elasticity analysis to interpret their contributions to l. If restoration efforts target the survival of age classes with high elasticities, significant population growth may be achieved.

Consequences of potential density-dependent mechanisms on recovery of ocean-type chinook salmon (Oncorhynchus tshawytscha)

2004 ◽  
Vol 61 (4) ◽  
pp. 590-602 ◽  
Author(s):  
Correigh M Greene ◽  
Timothy J Beechie
Keyword(s):  
Density Dependence ◽  
Chinook Salmon ◽  
Habitat Restoration ◽  
Oncorhynchus Tshawytscha ◽  
High Sensitivity ◽  
Leslie Matrix ◽  
Relative Importance ◽  
Density Dependent ◽  
Habitat Area ◽  
Leslie Matrix Model

Restoring salmon populations depends on our ability to predict the consequences of improving aquatic habitats used by salmon. Using a Leslie matrix model for chinook salmon (Oncorhynchus tshawytscha) that specifies transitions among spawning nests (redds), streams, tidal deltas, nearshore habitats, and the ocean, we compared the relative importance of different habitats under three density-dependent scenarios: juvenile density independence, density-dependent mortality within streams, delta, and nearshore, and density-dependent migration among streams, delta, and nearshore. Each scenario assumed density dependence during spawning. We examined how these scenarios influenced priorities for habitat restoration using a set of hypothetical watersheds whose habitat areas could be systematically varied, as well as the Duwamish and Skagit rivers. In all watersheds, the three scenarios shared high sensitivity to changes in in nearshore and ocean mortality and produced similar responses to changes in other parameters controlling mortality (i.e., habitat quality). However, the three scenarios exhibited striking variation in population response to changes in habitat area (i.e., capacity). These findings indicate that nearshore habitat relationships may play significant roles for salmon populations and that the relative importance of restoring habitat area will depend on the mechanism of density dependence influencing salmon stocks.

scholarly journals Survival of a threatened salmon is linked to spatial variability in river conditions

2021 ◽  
Author(s):  
Colby L. Hause ◽  
Gabriel P. Singer ◽  
Rebecca A. Buchanan ◽  
Dennis E. Cocherell ◽  
Nann A. Fangue ◽  
...  
Keyword(s):  
Pacific Northwest ◽  
Chinook Salmon ◽  
Habitat Restoration ◽  
Oncorhynchus Tshawytscha ◽  
Central Valley ◽  
Data Generation ◽  
Habitat Variability ◽  
River Habitat ◽  
San Joaquin River ◽  
The Pacific

AbstractExtirpation of the Central Valley spring-run Chinook Salmon ESU (Oncorhynchus tshawytscha) from the San Joaquin River is emblematic of salmonid declines across the Pacific Northwest. Habitat restoration and fish reintroduction efforts are ongoing, but recent telemetry studies have revealed low outmigration survival of juveniles to the ocean. Previous investigations have focused on modeling survival relative to river discharge and geographic regions, but have largely overlooked the effects of habitat variability. To evaluate the link between environmental conditions and survival of juvenile spring-run Chinook Salmon, we combined high spatial resolution habitat mapping approaches with acoustic telemetry along a 150 km section of the San Joaquin River during the spring of 2019. While overall outmigration survival was low (5%), our habitat-based classification scheme described variation in survival of acoustic-tagged smolts better than other candidate models based on geography or distance. There were two regional mortality sinks evident along the longitudinal profile of the river, revealing poor survival in areas that shared warmer temperatures but that diverged in chlorophyll-α, fDOM, turbidity and dissolved oxygen levels. These findings demonstrate the value of integrating river habitat classification frameworks to improve our understanding of survival dynamics of imperiled fish populations. Importantly, our data generation and modeling methods can be applied to a wide variety of fish species that transit heterogeneous and diverse habitat types.

scholarly journals Long-term monitoring reveals the success of salmonid habitat restoration

2016 ◽  
Vol 73 (12) ◽  
pp. 1733-1741 ◽  
Author(s):  
Pauliina Louhi ◽  
Teppo Vehanen ◽  
Ari Huusko ◽  
Aki Mäki-Petäys ◽  
Timo Muotka
Keyword(s):  
Salmo Trutta ◽  
Habitat Restoration ◽  
Woody Debris ◽  
Stream Habitat ◽  
Age Classes ◽  
Brown Trout Salmo Trutta ◽  
Extreme Hydrological Events ◽  
Juvenile Brown Trout ◽  
Forest Streams

The growing concern on declining salmonid populations has resulted in numerous restoration projects with variable responses worldwide. In this spatially replicated multiyear study, we assessed the long-term (12 years postrestoration) effects of in-stream habitat restoration (i.e., addition of boulders or large woody debris (LWD) together with boulders) on densities of three age-classes of juvenile brown trout (Salmo trutta) in six forest streams in northern Finland. LWD combined with boulders was more beneficial, particularly for the larger trout (age-2 and older), than were boulder structures alone, indicating that the more diverse habitat created by LWD may have provided a safeguard against drought for the larger fish. Density of age-0+ trout showed a significant long-term increase in boulder-restored sections, providing evidence that log structures may need to be complemented by stony enhancement structures to guarantee the availability of suitable stream habitat for all trout age-classes. As trout densities are known to exhibit inherently wide interannual variability that tracks climatically induced hydrological variation, long-term postrestoration monitoring that encompasses extreme hydrological events is critical for evaluating the success of restoration projects.

scholarly journals Synthesis of habitat restoration impacts on young-of-the-year salmonids in boreal rivers

2019 ◽  
Vol 29 (3) ◽  
pp. 513-527 ◽  
Author(s):  
Maare Marttila ◽  
Pauliina Louhi ◽  
Ari Huusko ◽  
Teppo Vehanen ◽  
Aki Mäki-Petäys ◽  
...  
Keyword(s):  
Habitat Restoration ◽  
Young Of The Year ◽  
Boreal Rivers
Sign in / Sign up

Export Citation Format

Share Document