Potential benefits of a conservation hatchery program for supplementing Oregon coast coho salmon (Oncorhynchus kisutch) populations: a stochastic model investigation

Abstract

This study developed a stochastic life cycle model to simulate idealized supplementation strategies to investigate the following question: under what circumstances could hatchery fish stocking contribute to the recovery of Oregon coast coho salmon (Oncorhynchus kisutch)? Simulations were used to find a solution space, defined by the attributes of wild and hatchery-bred salmon, their offspring, and their environments, where hatchery fish could supplement natural production without further depressing it until natural or human factors restricting production were relieved. These simulations suggest that short-duration, tightly controlled, low-intensity conservation hatchery programs designed to minimize genetic and ecological risks may yield minor short-term increases in adult coho salmon abundance while posing significant ecological and genetic risks. No solution space was found that indicated clear long-term benefits from such a supplementation program. Of all the management actions modeled, habitat restoration offered by far the largest and only permanent gains in coho salmon abundance while posing no genetic or ecological risk to the fish. The modeled benefits of habitat restoration were significant regardless of assumptions made about the fitness of hatchery fish and their offspring.

Effects of stocking on the genetic structure of brown trout, Salmo trutta, in Central Europe inferred from mitochondrial and nuclear DNA markers

“…habitat restoration, removing migration barriers, hydrological regime enhancement), which are generally more effective than stocking (Cowx 1994; Fjellheim et al. 2003; Oosterhout et al. 2005; Ferguson 2007).…”

Assessment of three strategies practiced by fishery managers for restoring native brown trout (Salmo trutta) populations in Northern French Alpine Streams

“…For example, the monitoring of a restoration programme of Steelhead showed that the use of local origin could increase the short-term abundance of depleted population and that could also cause longterm genetic change in the population (Carofino et al 2008). The simulation of supplementation strategies to conserve the coast Coho salmon (Oncorhynchus kisutch) populations revealed that the conservation hatchery programmes provided no significant increase in the abundance and caused significant ecological and genetic risks (Oosterhout et al 2005). The simulation of supplementation strategies to conserve the coast Coho salmon (Oncorhynchus kisutch) populations revealed that the conservation hatchery programmes provided no significant increase in the abundance and caused significant ecological and genetic risks (Oosterhout et al 2005).…”

Semidiscrete biomass dynamic modeling: an improved approach for assessing fish stock responses to pulsed harvest events

“…One example is the stocking of fish into aquatic systems to serve as biological controls (Lathrop et al 2002), provide additional fishing opportunities (Pine et al 2007), or promote species conservation (Oosterhout et al 2005). This discrete input of fish biomass can have major food web impacts through an instantaneous increase in the consumption required to support these newly stocked fish.…”