Managed Metapopulations: Do Salmon Hatchery ‘Sources’ Lead to In-River ‘Sinks’ in Conservation?

  title={Managed Metapopulations: Do Salmon Hatchery ‘Sources’ Lead to In-River ‘Sinks’ in Conservation?},
  author={Rachel C. Johnson and Peter K. Weber and John D Wikert and Michelle L. Workman and R. Bruce MacFarlane and Marty Grove and Axel K. Schmitt},
  journal={PLoS ONE},
Maintaining viable populations of salmon in the wild is a primary goal for many conservation and recovery programs. The frequency and extent of connectivity among natal sources defines the demographic and genetic boundaries of a population. Yet, the role that immigration of hatchery-produced adults may play in altering population dynamics and fitness of natural populations remains largely unquantified. Quantifying, whether natural populations are self-sustaining, functions as sources… 

Figures and Tables from this paper

Reconstructing the Migratory Behavior and Long-Term Survivorship of Juvenile Chinook Salmon under Contrasting Hydrologic Regimes
It is demonstrated that the expression and success of migratory phenotypes vary with hydrologic regime, emphasizing the importance of maintaining diversity in a changing climate.
Native and Invasive Macrophytes Differ in Their Effectiveness as Nurseries for Juvenile Endangered Salmon
The results suggest that invasive species can serve positive habitat functions, but only when in the presence of a habitat-forming native species, and supports the theory that habitat diversity leads to greater nursery function of coastal ecosystems.
Causes and Consequences of Straying into Small Populations of Pacific Salmon
The influence of population abundances on the magnitude of straying into recipient populations is highlighted and demonstrated using evidence collected from a small population of Sockeye Salmon O. nerka in British Columbia, Canada.
Size, growth, and origin-dependent mortality of juvenile Chinook salmon Oncorhynchus tshawytscha during early ocean residence
The results suggest that Central Valley Chinook salmon can be subject to significant size and growth-rate selective mortality resulting in low adult abundance, and this mortality appears independent of origin.
Fishery collapse, recovery, and the cryptic decline of wild salmon on a major California river
Though the rebound in abundance of salmon in the Feather River suggests recovery of the stock postcollapse, otolith chemistry data document a persistent decline of wild spawners, likely leading to the erosion of locally adapted Feather River salmon populations.
Isotopes and genes reveal freshwater origins of Chinook salmon Oncorhynchus tshawytscha aggregations in California's coastal ocean
The findings are consistent with coarser information indicating stocks are distributed differ- ently in time and space, but larger sample sizes are required to evaluate the consistency of consistency at smaller spatial scales.
Biogeochemical processes create distinct isotopic fingerprints to track floodplain rearing of juvenile salmon
It is suggested that δ¹³C and δ²³⁴S can be used to differentiate floodplain and river rearing habitats used by native fishes, such as Chinook Salmon, across different hydrologic conditions and tissues, and provide a toolset to quantify the role of floodplains as fish habitats.
Potential Factors Affecting Survival Differ by Run-Timing and Location: Linear Mixed-Effects Models of Pacific Salmonids (Oncorhynchus spp.) in the Klamath River, California
The relationship between ten factors and survival of four populations of salmonids with distinct life histories from two adjacent watersheds in the Klamath River basin, California are analyzed to underscore the importance of multiple factors in simultaneously driving population trends in widespread species such as anadromous salmonids.
Reconstructing marine life-history strategies of wild Atlantic salmon from the stable isotope composition of otoliths
The present uncertainty in otolith thermometry parameters for an open-ocean fish such as Atlantic salmon preclude firm conclusions based on these estimates, but a marked and rapid decrease in the δ¹³C values of some fish in the last month(s) of the marine migration could be an indicator of physiological changes occurring during the homing migration.


Reproductive Success of Captive‐Bred Steelhead Trout in the Wild: Evaluation of Three Hatchery Programs in the Hood River
These are the first data to show that a supplementation program with native brood stock can provide a single‐generation boost to the size of a natural steelhead population without obvious short‐term fitness costs.
We examined the reproductive success and long—term population dynamics of Neotropical migrant birds in the fragmented landscapes of Illinois. Our primary objective was to assess whether annual
Reduced recruitment performance in natural populations of anadromous salmonids associated with hatchery-reared fish
A negative relationship between the reproductive performance in natural, anadromous populations of steelhead trout, coho salmon and Chinook salmon, and the propor- tion of hatchery fish in the spawning population is found.
A metapopulation perspective for salmon and other anadromous fish
A metapopulation perspective for anadromous fish is presented, assessing in terms of processes rather than of patterns the set of necessary conditions for metapobulation dynamics to exist, and salmon, and particularly sockeye salmon in Alaska, are used as an illustrative case study.
The Effects of Small Dispersal Rates on Extinction Times in Structured Metapopulation Models
It is found that, for moderate levels of environmental variability, small dispersal rates can significantly increase mean extinction times, and this effect declines with increasing habitat quality, increasing temporal correlation, and increasing spatial correlation, but it is still significant for realistic parameter values.
Fitness reduction and potential extinction of wild populations of Atlantic salmon, Salmo salar, as a result of interactions with escaped farm salmon
It is demonstrated that interaction of farm with wild salmon results in lowered fitness, with repeated escapes causing cumulative fitness depression and potentially an extinction vortex in vulnerable populations.
Natural isotope markers in salmon
Using differences in the ratio of stable isotopes of strontium (Sr), found naturally in stream water, it is able to distinguish juvenile Atlantic salmon from eight of ten rearing sites studied in Vermont streams, demonstrating the potential for using environmental signals to determine the rearing stream from which salmon originate.
Identifying the contribution of wild and hatchery Chinook salmon (Oncorhynchus tshawytscha) to the ocean fishery using otolith microstructure as natural tags
Results from the mixed-stock model estimated that the contribution of wild fish was 10% ± 6%, indicating hatchery supplementation may be playing a larger role in supporting the central California coastal fishery than previ- ously assumed.
Tracking natal origins of salmon using isotopes, otoliths, and landscape geology
The inability to identify natal origins (i.e., individual rivers and hatcheries) of adult Pacific salmon in the ocean has impeded our understanding of their ocean ecology and the management of
Long‐Term Demographic Responses of Trout Populations to Habitat Manipulation in Six Colorado Streams
This research shows that log weirs increase trout abundance, but only if other management activities assure that fish dispersal remains unimpeded within the drainage, and detected a high degree of concordance in fish abundance fluctuations within and among streams.