Using an unplanned experiment to evaluate the effects of hatcheries and environmental variation on threatened populations of wild salmon

Buhle, Eric R.; Holsman, Kirstin K.; Scheuerell, Mark D.; Albaugh, Andrew

doi:10.1016/j.biocon.2009.05.013

Cited by 55 publications

(68 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is also known that hatchery-reared salmon do not survive as well as their wild counterparts (Cross et al 1991;Jonsson et al 1991). These differences in survival may indicate that there were ecological differences between the hatchery and wild fish, as observed in other studies (Beauchamp 2009;Buhle et al 2009). …”

Section: Discussionmentioning

confidence: 88%

Wild chinook salmon survive better than hatchery salmon in a period of poor production

et al. 2011

View full text Add to dashboard Cite

show abstract

Section: Discussionmentioning

confidence: 88%

Wild chinook salmon survive better than hatchery salmon in a period of poor production

et al. 2011

View full text Add to dashboard Cite

show abstract

“…Possibly exacerbating this scenario is the release of hatchery fish, which is commonly used to augment salmon populations (e.g., Einum et al 2009). Artificial supplementation of fish populations or other species has clear benefits when they face immediate risk of extinction (Young 1999), but in resource-limited systems it may have negative demographic consequences for wild populations because territorial species, such as stream-dwelling salmonids, are strongly affected by density-dependent interactions (our study, Jenkins et al 1999, Grant and Imre 2005, Buhle et al 2009, Einum et al 2009). …”

Section: Synthesis and Implicationsmentioning

confidence: 97%

Linking resource availability and habitat structure to stream organisms: an experimental and observational assessment

et al. 2014

View full text Add to dashboard Cite

An experiment and a mark‐recapture field study of juvenile coho salmon (Oncorhynchus kisutch) were conducted to identify controls of key energy flow chains in river food webs. In the small‐scale experiment, we investigated the individual and interactive effects of physical habitat structure (PHS) as small wood and resource availability (tissue of adult Chinook salmon, O. tshawytscha) on nutrients, algae, invertebrates, and fish predators including juvenile coho. In the field, we quantified the effects of natural variation in prey availability (invertebrate drift biomass), PHS (wood), and local fish density on summer growth of juvenile coho across multiple stream reaches. Adding salmon tissue to experimental channels resulted in strong bottom‐up effects on select invertebrates including increased population biomass of chironomids and baetids, the numerically dominant invertebrates, and faster growth of juvenile coho. We link the enhanced growth of coho to chironomid productivity: for instance, adult chironomid flux was 4.3× higher and coho consumption of these animals 3× higher in salmon‐subsidized channels. PHS in experimental channels was associated with reduced algal biomass, potentially in response to increased invertebrate consumption, and invertebrate flux or export. The field study revealed coho growth was negatively related to PHS and total fish density and positively related to Diptera drift biomass; however, the effects of fish density and drift biomass on coho growth were relatively weak. The field study also indicated that prey resource availability and coho growth were associated with differences in canopy cover, with prey biomass and coho growth 2–4× higher in reaches receiving more sunlight. As in the experiment, coho in natural stream reaches predominantly fed on adult chironomids and other Diptera, indicating that these taxa and life‐stages are a key link between the benthic food web and mobile vertebrate predators. Our study showed that bottom‐up processes initiated by salmon subsidies and possibly light flux determined key trophic interactions in the Cedar River food web. Moreover, we speculate that PHS may modify some of these interactions indirectly through its effects on the movement of organisms through the environment.

show abstract

“…Hatchery salmon may reduce variability in harvests but this benefit to fishermen may come with a cost to wild salmon productivity. Additionally, there can be substantial straying of hatchery fish into natural spawning areas, which can degrade the fitness and biological diversity of the wild populations (e.g., Levin et al 2001;Ford 2002;Naish et al 2007;Buhle et al 2009). …”

Section: Management Implicationsmentioning

confidence: 99%

Magnitude and Trends in Abundance of Hatchery and Wild Pink Salmon, Chum Salmon, and Sockeye Salmon in the North Pacific Ocean

et al. 2010

View full text Add to dashboard Cite

Abundance estimates of wild and hatchery Pacific salmon Oncorhynchus spp. are important for evaluation of stock status and density‐dependent interactions at sea. We assembled available salmon catch and spawning abundance data for both Asia and North America and reconstructed total abundances of pink salmon O. gorbuscha, chum salmon O. keta, and sockeye salmon O. nerka during 1952–2005. Abundance trends were evaluated with respect to species, regional stock groups, and climatic regimes. Wild adult pink salmon were the most numerous salmon species (average = 268 × 106 fish/year, or 70% of the total abundance of the three species), followed by sockeye salmon (63 × 106 fish/year, or 17%) and chum salmon (48 × 106 fish/year, or 13%). After the 1976–1977 ocean regime shift, abundances of wild pink salmon and sockeye salmon increased by more than 65% on average, whereas abundance of wild chum salmon was lower in recent decades. Although wild salmon abundances in most regions of North America increased in the late 1970s, abundances in Asia typically did not increase until the 1990s. Annual releases of juvenile salmon from hatcheries increased rapidly during the 1970s and 1980s and reached approximately 4.5 × 109 juveniles/year during the 1990s and early 2000s. During 1990–2005, annual production of hatchery‐origin adult salmon averaged 78 × 106 chum salmon, 54 × 106 pink salmon, and 3.2 × 106 sockeye salmon, or approximately 62, 13, and 4%, respectively, of the combined total wild and hatchery salmon abundance. The combined abundance of adult wild and hatchery salmon during 1990–2005 averaged 634 × 106 salmon/year (498 × 106 wild salmon/year), or approximately twice as many as during 1952–1975. The large and increasing abundances of hatchery salmon have important management implications in terms of density‐dependent processes and conservation of wild salmon populations; management agencies should improve estimates of hatchery salmon abundance in harvests and on the spawning grounds.

show abstract

Using an unplanned experiment to evaluate the effects of hatcheries and environmental variation on threatened populations of wild salmon

Cited by 55 publications

References 29 publications

Wild chinook salmon survive better than hatchery salmon in a period of poor production

Wild chinook salmon survive better than hatchery salmon in a period of poor production

Linking resource availability and habitat structure to stream organisms: an experimental and observational assessment

Magnitude and Trends in Abundance of Hatchery and Wild Pink Salmon, Chum Salmon, and Sockeye Salmon in the North Pacific Ocean

Contact Info

Product

Resources

About