The ecology of terrestrial invertebrates on Pacific salmon carcasses

2009 ◽  
Vol 24 (5) ◽  
pp. 1091-1100 ◽  
Author(s):  
Morgan D. Hocking ◽  
Richard A. Ring ◽  
Thomas E. Reimchen
Keyword(s):  
Pacific Salmon ◽  
Terrestrial Invertebrates ◽  
Salmon Carcasses

Pacific Salmon: Ecology and Management of Western Alaska’s Populations

2009 ◽  
Keyword(s):  
Food Source ◽  
Driving Forces ◽  
Pacific Salmon ◽  
Late Summer ◽  
Terrestrial Ecosystems ◽  
Food Resources ◽  
Growth And Survival ◽  
Terrestrial Invertebrates ◽  
Riverine Ecosystems ◽  
Aquatic Food

<em>Abstract.</em>—Much is known about the importance of the physical characteristics of salmonid habitat in Alaska and the Pacific Northwest, with far less known about the food sources and trophic processes within these habitats, and the role they play in regulating salmonid productivity. Freshwater food webs supporting salmonids in Alaska rely heavily on nutrient, detritus, and prey subsidies from both marine and terrestrial ecosystems. Adult salmon provide a massive input of marine biomass to riverine ecosystems each year when they spawn, die, and decompose, and are a critical food source for young salmon in late summer and fall; riparian forests provide terrestrial invertebrates to streams, which at times comprise over half of the food ingested by stream-resident salmonids; up-slope, fishless headwater streams are a year-round source of invertebrates and detritus for fish downstream. The quantity of these food resources vary widely depending on source, season, and spatial position within a watershed. Terrestrial invertebrate inputs from riparian habitats are generally the most abundant food source in summer. Juvenile salmonids in streams consume roughly equal amounts of freshwater and terrestrially-derived invertebrates during most of the growing season, but ingest substantial amounts of marine resources (salmon eggs and decomposing salmon tissue) when these food items are present. Quantity, quality, and timing of food resources all appear to be important driving forces in aquatic food web dynamics, community nutrition, and salmonid growth and survival in riverine ecosystems.

Pacific Salmon Carcasses: Essential Contributions of Nutrients and Energy for Aquatic and Terrestrial Ecosystems

Fisheries ◽  
1999 ◽  
Vol 24 (10) ◽  
pp. 6-15 ◽  
Author(s):  
C. Jeff Cederholm ◽  
Matt D. Kunze ◽  
Takeshi Murota ◽  
Atuhiro Sibatani
Keyword(s):  
Pacific Salmon ◽  
Terrestrial Ecosystems ◽  
Salmon Carcasses

Seasonal changes in diets of coastal and riverine mink: the role of spawning Pacific salmon

1997 ◽  
Vol 75 (5) ◽  
pp. 803-811 ◽  
Author(s):  
M. Ben-David ◽  
T. A. Hanley ◽  
D. R. Klein ◽  
D. M. Schell
Keyword(s):  
Stable Isotope ◽  
Pacific Salmon ◽  
Isotope Ratios ◽  
Stable Isotope Ratios ◽  
Upstream Migration ◽  
Southeast Alaska ◽  
Prey Composition ◽  
Isotope Analyses ◽  
Salmon Carcasses

Feeding niches of riverine and coastal mink (Mustela vison) in southeast Alaska differ in prey composition and abundance and diving medium during spring and summer. In autumn, however, the upstream migration of spawning Pacific salmon (Oncorhynchus sp.) creates a pulse of food for mink. We hypothesized that diets of coastal and riverine mink, and therefore their stable isotope ratios (δ13C, δ15N), would differ significantly during periods when salmon were absent, but that salmon carcasses would constitute a large portion of the diet of both groups during the salmon spawning season. Stable isotope analyses of clotted blood cells from 24 live-captured mink and muscle tissue from 25 mink carcasses were used to indicate the composition of diets of individual mink in 1992 and 1993. These isotope values were then compared with stable isotope ratios of prey, using a multiple-source mixing model. Our results indicate that riverine mink depended on salmon (carcasses and fry), with little seasonal or individual variation, whereas coastal mink relied on intertidal organisms in spring and summer, with measurable (<25%) consumption of salmon carcasses when they became available in autumn. Coastal and riverine mink in southeast Alaska differ strongly in their diets in spring and summer, with both groups relying on the abundant salmon carcasses during autumn.

Transportation of Pacific salmon carcasses from streams to riparian forests by bears

2009 ◽  
Vol 87 (3) ◽  
pp. 195-203 ◽  
Author(s):  
Thomas P. Quinn ◽  
Stephanie M. Carlson ◽  
Scott M. Gende ◽  
Harry B. Rich, Jr.
Keyword(s):  
Spatial Distribution ◽  
Aquatic Ecosystems ◽  
Sockeye Salmon ◽  
Pacific Salmon ◽  
Riparian Forests ◽  
Oncorhynchus Gorbuscha ◽  
Oncorhynchus Keta ◽  
Ecosystem Process ◽  
Direct Observations ◽  
Salmon Carcasses

Predation on Pacific salmon by bears (genus Ursus L., 1758) can be an important ecosystem process because the spatial distribution of carcasses largely determines whether marine-derived nutrients cycle through aquatic or terrestrial pathways. Direct observations on three streams in southeastern Alaska indicated that 49% of the pink ( Oncorhynchus gorbuscha (Walbaum, 1792)) and chum ( Oncorhynchus keta (Walbaum in Artedi, 1792)) salmon killed by bears were carried into the forest. The tendency of bears to transport carcasses was independent of the sex and species of salmon, but unspawned fish were more often transported than fish that had completed spawning. Data on tagged sockeye salmon ( Oncorhynchus nerka (Walbaum in Artedi, 1792)) in one southwestern Alaska stream indicated that 42.6% of the killed salmon were transported, and that higher percentages were transported in years when salmon densities were greater. At six other streams, on average, 68.1% of the sockeye salmon killed were apparently transported away from the stream into the forest. Combining the data from all sites, the proportion of carcasses transported increased with water depth at the site. These results emphasize the role that bears play in mediating the interactions between nutrients from salmon and the terrestrial and aquatic ecosystems, and the variation in carcass distribution among streams and among years.

Nitrogen uptake by plants subsidized by Pacific salmon carcasses: a hierarchical experiment

2012 ◽  
Vol 42 (5) ◽  
pp. 908-917 ◽  
Author(s):  
Morgan D. Hocking ◽  
John D. Reynolds
Keyword(s):  
Pacific Salmon ◽  
Spatial Scales ◽  
Experimental Manipulation ◽  
Oncorhynchus Keta ◽  
Individual Plant ◽  
Riparian Areas ◽  
Moss Species ◽  
Foliar N ◽  
Habitat Variation ◽  
Salmon Carcasses

Bears ( Ursus spp.) and other predators can capture and transport large numbers of Pacific salmon ( Oncorhynchus spp.) to riparian areas beside small coastal streams, a process that may affect site productivity and local plant communities. We used a novel experimental manipulation of salmon carcasses to analyze understory plant uptake of salmon-derived N. A hierarchical before–after, control–impact design was used with the addition of chum salmon ( Oncorhynchus keta (Walbaum in Artedi, 1792)) carcasses to forest sites along 11 streams on the central coast of British Columbia, Canada. Eight months after carcass placement, the foliar %N and δ15N in three herbaceous and one moss species had increased by an average of 14%–60% (%N) and 0.5–3.3‰ (δ15N) at treatment carcass sites versus control sites. Treatment effects for %N were typically greater than for δ15N. Nitrogen isotope signatures at carcass sites were highly variable (δ15N range = 30.1‰) and were mediated by plant species, stream salmon density, carcass mass, and individual plant foliar %N. These results show that understory plants use N from salmon during an important period of plant growth many months after carcasses were deposited in riparian areas. However, they also indicate that habitat variation across spatial scales from individual plants to streams needs to be considered when estimating the contribution of salmon to plant nutrition.

Consumption and distribution of salmon (Oncorhynchus spp.) nutrients and energy by terrestrial flies

2006 ◽  
Vol 63 (9) ◽  
pp. 2076-2086 ◽  
Author(s):  
Morgan D Hocking ◽  
Thomas E Reimchen
Keyword(s):  
Chum Salmon ◽  
Pacific Salmon ◽  
Pink Salmon ◽  
Isotope Analysis ◽  
Terrestrial Ecosystems ◽  
Oncorhynchus Gorbuscha ◽  
Oncorhynchus Keta ◽  
The North ◽  
Terrestrial Habitats ◽  
Salmon Carcasses

Anadromous Pacific salmon (Oncorhynchus spp.) subsidize terrestrial food webs with their nutrients and carcasses, a process driven largely by selective foraging by bears (Ursus spp.). We quantify wildlife transfer of salmon carcasses to riparian zones on two watersheds in coastal British Columbia and estimate total terrestrial fly production from remnant carcasses. Large-bodied chum salmon (Oncorhynchus keta) were transferred into the forest at a greater rate than were pink salmon (Oncorhynchus gorbuscha) (chum salmon mass = 6089–11 031 kg, 16%–48% of salmon run; pink salmon mass = 2266–2808 kg, 4%–6% of salmon run). Blow flies (genus Calliphora) and other Diptera dominated colonization (>90% of salmon carcasses). Between the two watersheds, 196 and 265 g of Calliphora larvae per metre of spawning length (4 and 7 million larvae for whole watersheds) were generated from salmon carcass transfer. Stable isotope analysis of δ15N and δ13C of spring-emerging adult Calliphora revealed that >80% of individuals had salmon-based signatures. Flies are a dominant consumer and vector of salmon nutrients in terrestrial habitats and supplement the diet of at least 16 vertebrate and 22 invertebrate species. Anticipated further declines of salmon in the North Pacific can be expected to further erode the complex associations coupling marine and terrestrial ecosystems.

Can nutrient additions facilitate recovery of Pacific salmon?

2020 ◽  
Vol 77 (10) ◽  
pp. 1601-1611 ◽  
Author(s):  
Joseph R. Benjamin ◽  
J. Ryan Bellmore ◽  
Emily Whitney ◽  
Jason B. Dunham
Keyword(s):  
Aquatic Ecosystems ◽  
Pacific Salmon ◽  
Limiting Factors ◽  
Cycle Model ◽  
Nutrient Additions ◽  
Salmon Population ◽  
River Reach ◽  
Salmon Carcasses ◽  
Food Web Model

Multiple restoration actions have been implemented in response to declining salmon populations. Among these is the addition of salmon carcasses or artificial nutrients to mimic marine-derived nutrients historically provided by large spawning runs of salmon. A key assumption in this approach is that increased nutrients will catalyze salmon population growth. Although effects on aquatic ecosystems have been observed during treatments, it is unclear whether permanent population increases for salmon will occur. To test this assumption and address associated uncertainties, we linked a food web model with a salmon life cycle model to examine whether carcass additions in a river reach would improve conditions for salmon in the long term. Model results confirmed immediate increases in the biomass of periphyton, macroinvertebrates, and fish during carcass additions. In turn, juvenile salmon grew larger and experienced improved freshwater and smolt survival, which translated to a greater number of adults returning to spawn. However, once additions ceased, salmon abundance returned to pretreatment levels, which, based on our model, is owing to a combination of instream and out-of-basin factors. Overall, results of this work suggest that benefits during carcass and nutrient additions may not translate into persistent productivity of salmon unless additions are sustained indefinitely or other limiting factors are addressed.

Mass loss and macroinvertebrate colonisation of Pacific salmon carcasses in south-eastern Alaskan streams

2002 ◽  
Vol 47 (2) ◽  
pp. 263-273 ◽  
Author(s):  
Dominic T. Chaloner ◽  
Mark S. Wipfli ◽  
John P. Caouette
Keyword(s):  
Mass Loss ◽  
Pacific Salmon ◽  
South Eastern ◽  
Salmon Carcasses
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