Snake River Spring and Summer Chinook Salmon—The Choice for Recovery

Nemeth, Douglas J.; Kiefer, Russell B.

doi:10.1577/1548-8446(1999)024<0016:srsasc>2.0.co;2

Cited by 17 publications

(12 citation statements)

References 6 publications

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“…The exact magnitude of the average amount of survival improvement needed in different life stages to truly achieve target values of λ is therefore uncertain. However, the large magnitude of the required increase suggested by the direct perturbation and historical analyses comports with estimates from other sources ( Nemeth & Kiefer 1999; Petrosky et al 2001 ).…”

Section: Discussionmentioning

confidence: 72%

Using Population Projection Matrices to Evaluate Recovery Strategies for Snake River Spring and Summer Chinook Salmon

Wilson

2003

Conservation Biology

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I explored the efficacy of alternative actions to recover threatened Snake River chinook salmon ( Onchorhyncus tshawytscha ). I compared the potential to increase population growth rates from two different actions: (1) habitat restoration efforts, aimed at increasing egg-to-smolt survival rate, and (2) dam breaching, intended to improve smolt-to-spawner survival. Eight dams obstruct the migration corridor these populations traverse as juveniles (downstream) and as adults (upstream), and a large portion of the juvenile migrants are collected and transported past most of the dams on barges or trucks. I applied sensitivity, elasticity, and direct perturbation analyses to an age-structured projection matrix to predict potential effects from simultaneous, nonproportional changes in multiple survival rates. Throughout the analyses, I explicitly incorporated alternative assumptions about the effectiveness of transportation, which is known to be influential. Results of the numerical experiments suggest that dam breaching has more potential to increase population growth rates than habitat restoration, except for the most optimistic assumption about the efficacy of transportation. I then fit the matrix to historical data to identify life stages in which actual decreases in survival rates have caused the observed declines in abundance. There was no reduction in egg-to-smolt survival, indicating that neither habitat deterioration nor hatchery impacts (in that life stage) caused the stocks to decline. The large decrease in smolt-to-adult survival rate from the historical period, when there were fewer dams, is consistent with the hypothesis that increased stress from transportation and passage through additional dams on the Snake River has elevated delayed mortality levels. Análisis Matricial de la Recuperación de Salmón en el Río SnakeResumen: Exploré la eficacia de acciones alternativas para recuperar al salmón ( Onchorhyncus tshawytscha ) amenazado en el Río Snake. Comparé el incremento potencial de las tasas de crecimiento poblacional mediante dos acciones diferentes: (1) esfuerzos para la restauración del hábitat, enfocados a incrementar la tasa de supervivencia de huevo a juvenil y (2) apertura de represas con la intención de mejorar la supervivencia de juvenil a reproductor. Ocho represas obstruyen el corredor migratorio que recorren estas poblaciones cuando son juveniles (aguas abajo) y cuando son adultos (aguas arriba), por lo cual se recolecta y transporta una gran porción de los juveniles migrantes en barcazas o camiones para que puedan atravesar la mayoría de las represas. Apliqué un análisis de sensibilidad, elasticidad y perturbación directa a una proyección matricial estructurada por edades para predecir los efectos de cambios no proporcionales, simultáneos sobre tasas de supervivencia múltiples. Durante los análisis, se incorporaron explícitamente supuestos alternativos sobre la efectividad del transporte, cuya influencia se conoce. Los resultados de los experimentos numéricos sugieren que la apertura de presas...

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Section: Discussionmentioning

confidence: 72%

Using Population Projection Matrices to Evaluate Recovery Strategies for Snake River Spring and Summer Chinook Salmon

Wilson

2003

Conservation Biology

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“…The conflict over the conservation of chinook salmon (Oncorhynchus tshawytscha) in the US Pacific Northwest provides a contrasting example. Several runs of Snake River chinook are listed as endangered under the US Endangered Species Act, and have been in decline since the early 1970s, presumably due to dam construction for hydropower and other human uses (Nemeth and Kiefer 1999). Initial solutions to this problem involved transporting migrating fish around dams, a mitigation action that has been unsuccessful in terms of arresting population decline (Nemeth and Kiefer 1999).…”

Section: Designing An Effective Policy Toolmentioning

confidence: 99%

Compensatory mitigation as a solution to fisheries bycatch–biodiversity conservation conflicts

Wilcox¹,

Donlan²

2007

Frontiers in Ecology and the Environment

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Globally, fisheries catch of non‐target species has major environmental impacts, resulting in social conflict, litigation, and fisheries closures. We use a bio‐economic approach to demonstrate that compensatory mitigation – an innovative, market‐influenced approach to fishery–conservation conflicts – can facilitate high‐value uses of biological resources and cost‐effective conservation gains for species of concern. We illustrate the strategy with a seabird example: levying fishers for their bycatch and using the funds to remove invasive mammals from breeding islands. Removal of invasive predators is 23 times more effective from a return‐on‐investment perspective (ie percent increase in population growth per dollar invested) in comparison to fisheries closures, and is more socio‐politically feasible. A bycatch levy, which would increase with endangerment, provides an individual incentive for avoiding bycatch, the most effective mechanism for sustainable management of fisheries. Compensatory mitigation provides an opportunity to address a global concern, optimize conservation interventions, and forge an alliance between conservation and fisheries organizations.

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“…Many Chinook salmon populations are threatened or endangered (e.g. Fisher 1994;Yoshiyama et al 1998;Nemeth and Kiefer 1999) and supportive breeding is now widely used in an attempt to enhance wild populations (Hedrick et al 2000). Here, we cross 11 females with 11 males in a quantitative genetic breeding design and rear the resulting 121 sib groups (in replicate) through the endogenous feeding period.…”

Section: Introductionmentioning

confidence: 99%

Genetic quality and offspring performance in Chinook salmon: implications for supportive breeding

Pitcher

Neff

2006

Conserv Genet

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Each year salmon and other fishes are caught and used for supportive breeding programs that attempt to augment natural populations that are threatened with extinction. These programs typically mate individuals randomly and as such they overlook the importance of genetic quality to offspring fitness and ultimately to ensuring population health. Here, we use Chinook salmon (Oncorhynchus tshawytscha) and a fully crossed quantitative genetic breeding design to partition genetic variance in offspring performance (growth and survival) to additive and non-additive genetic effects as well as maternal effects. We show that these three effects contribute about equally to the variation in survival, but only non-additive genetic and maternal effects contribute to variation in growth. Some of the genetic effects could be assigned to variation at the class IIB locus of the major histocompatibility complex, but the maternal effects were not associated with egg size and we found no relationship between dam phenotypic measures and offspring survival or growth. We also found no relationship between sire sexually selected characters and offspring survival or growth, which is inconsistent with a ''good genes'' hypothesis. Finally, we show that incorporation of genetic quality into supportive breeding programs can increase offspring growth or survival by between 3% and 19% during the endogenous feeding stage alone, and projections to adulthood suggest that survivorship could be over four fold higher.

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Snake River Spring and Summer Chinook Salmon—The Choice for Recovery

Cited by 17 publications

References 6 publications

Using Population Projection Matrices to Evaluate Recovery Strategies for Snake River Spring and Summer Chinook Salmon

Using Population Projection Matrices to Evaluate Recovery Strategies for Snake River Spring and Summer Chinook Salmon

Compensatory mitigation as a solution to fisheries bycatch–biodiversity conservation conflicts

Genetic quality and offspring performance in Chinook salmon: implications for supportive breeding

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