Marine carbon and nitrogen in southeastern Alaska stream food webs: evidence from artificial and natural streams

2002 ◽  
Vol 59 (8) ◽  
pp. 1257-1265 ◽  
Author(s):  
Dominic T Chaloner ◽  
Kristine M Martin ◽  
Mark S Wipfli ◽  
Peggy H Ostrom ◽  
Gary A Lamberti
Keyword(s):  
Food Webs ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Cutthroat Trout ◽  
Aquatic Organisms ◽  
Trophic Levels ◽  
Total N ◽  
Natural Streams ◽  
Chironomid Midges ◽  
Stream Food Webs

Incorporation of marine-derived nutrients (MDN) into freshwater food webs of southeastern Alaska was studied by measuring the natural abundance of nitrogen and carbon stable isotopes in biota from artificial and natural streams. Biofilm, aquatic macroinvertebrates (detritivores, shredders, and predators), and fish (coho salmon, Oncorhynchus kisutch, and cutthroat trout, Oncorhynchus clarki) were sampled from streams in which Pacific salmon (Oncorhynchus spp.) carcasses had been artificially placed or were present naturally. In the presence of carcasses, all trophic levels incorporated marine-derived nitrogen (range, 22–73% of total N) and carbon (range, 7–52% of total C). In general, chironomid midges assimilated more marine-derived nitrogen and carbon than did other consumers. The assimilation of MDN by aquatic organisms and subsequent isotopic enrichment (5–6‰ for 15N, 3–4‰ for 13C) were similar in experimentally and naturally carcass-enriched streams. For specific taxa, however, percent assimilation for marine nitrogen and carbon were often dissimilar, possibly because of fractionation or transfer inefficiencies. These results suggest that pathways of MDN incorporation into stream food webs include both consumption of salmon material by macroinvertebrates and fish and uptake of mineralized MDN by biofilm. Incorporation of MDN into multiple trophic levels demonstrates the ecological significance of annual returns of anadromous fishes for sustaining the productivity of freshwater food webs.

Production of germline transgenic Pacific salmonids with dramatically increased growth performance

1995 ◽  
Vol 52 (7) ◽  
pp. 1376-1384 ◽  
Author(s):  
Robert H. Devlin ◽  
Timothy Y. Yesaki ◽  
Edward M. Donaldson ◽  
Shao Jun Du ◽  
Choy-Leong Hew
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Cutthroat Trout ◽  
Transgenic Fish ◽  
Somatic Tissue ◽  
Growth Enhancement ◽  
Gene Construct ◽  
Average Size

Transgenic Pacific salmon have been produced by microinjection of a DNA construct consisting of chinook salmon (Oncorhynchus tshawytscha) growth hormone sequences driven by an ocean pout (Macrozoarces americanus) antifreeze protein promoter. This construct was retained in approximately 4% of fish derived from injected eggs, and resulted in dramatic enhancement of growth relative to controls. For coho salmon (O. kisutch) at 15 months of age, the average size of transgenic fish was more than 10-fold that of controls, with the largest fish more than 30-fold larger than nontransgenic siblings. Dramatic growth enhancement was also observed in transgenic rainbow trout (O. mykiss), cutthroat trout (O. clarki), and chinook salmon using this same gene construct. Transgenic coho salmon underwent precocious parr–smolt transformation during their first fall, approximately 6 months in advance of their nontransgenic siblings. At 2 years of age, five male transgenic coho salmon became sexually mature, and four of these transmitted the gene construct to sperm, the negative fish being transgenic in blood but not fin tissue. These results show that while some fish are mosaic for the gene construct in different tissues, most are transgenic in both germline and somatic tissue.

Terrestrial invertebrates as salmonid prey and nitrogen sources in streams: contrasting old-growth and young-growth riparian forests in southeastern Alaska, U.S.A.

1997 ◽  
Vol 54 (6) ◽  
pp. 1259-1269 ◽  
Author(s):  
Mark S Wipfli
Keyword(s):  
Statistical Power ◽  
Coho Salmon ◽  
Fork Length ◽  
Cutthroat Trout ◽  
Timber Harvesting ◽  
Trophic Levels ◽  
Old Growth ◽  
Nitrogen Inputs ◽  
Significant Difference ◽  
Young Growth

Terrestrial-derived invertebrate (TI) inputs into streams and predation on them by salmonids (40-180 mm fork length) were measured in six coastal Alaska stream reaches from April through October 1993-1994; riparian habitat of three stream reaches contained conifer-dominated old-growth (no timber harvesting) and three were alder-dominated young-growth (31 years postclearcutting). Data from pan-traps placed on stream surfaces showed that TI biomass and nitrogen inputs averaged up to 66 and 6 mg ·m-2 ·day-1, respectively, with no significant difference between habitats. Stomach contents from coho salmon (Oncorhynchus kisutch), cutthroat trout (O. clarki), and Dolly Varden (Salvelinus malma) revealed that TI and aquatic-derived invertebrates (AI) were equally important prey. Additionally, salmonids from young-growth systems ingested a greater TI proportion than those from old-growth systems. There were trends but no significant differences between habitats of TI and AI biomass ingested; however, statistical power was <0.30. These results showed that TI were important juvenile salmonid prey and that a riparian overstory with more alder and denser shrub understory may increase their abundance. Riparian vegetation management will likely have important consequences on trophic levels supporting predators, including but not limited to fishes.

Anadromous alewives (Alosa pseudoharengus) contribute marine-derived nutrients to coastal stream food webs

2009 ◽  
Vol 66 (3) ◽  
pp. 439-448 ◽  
Author(s):  
Annika W. Walters ◽  
Rebecca T. Barnes ◽  
David M. Post
Keyword(s):  
Food Web ◽  
Food Webs ◽  
Nutrient Dynamics ◽  
Pacific Salmon ◽  
Atlantic Coast ◽  
Trophic Levels ◽  
Spawning Migration ◽  
Alosa Pseudoharengus ◽  
Nutrient Influx ◽  
Isotope Analyses

Diadromous fish are an important link between marine and freshwater food webs. Pacific salmon ( Oncorhynchus spp.) strongly impact nutrient dynamics in inland waters and anadromous alewife ( Alosa pseudoharengus ) may play a similar ecological role along the Atlantic coast. The annual spawning migration of anadromous alewife contributes, on average, 1050 g of nitrogen and 120 g of phosphorus to Bride Brook, Connecticut, USA, through excretion and mortality each year. Natural abundance stable isotope analyses indicate that this influx of marine-derived nitrogen is rapidly incorporated into the stream food web. An enriched δ15N signal, indicative of a marine origin, is present at all stream trophic levels with the greatest level of enrichment coincident with the timing of the anadromous alewife spawning migration. There was no significant effect of this nutrient influx on water chemistry, leaf decomposition, or periphyton accrual. Dam removal and fish ladder construction will allow anadromous alewife to regain access to historical freshwater spawning habitats, potentially impacting food web dynamics and nutrient cycling in coastal freshwater systems.

scholarly journals METAL BIOACCUMULATION IN FISHES AND MACRO ZOOPLANKTON IN SOME LAKES IN HA NOI

2018 ◽  
Vol 56 (2C) ◽  
pp. 96-103 ◽  
Author(s):  
Pham Thi Hong
Keyword(s):  
Food Webs ◽  
Fish Species ◽  
Metal Accumulation ◽  
Labeo Rohita ◽  
Aquatic Organisms ◽  
Trophic Levels ◽  
Polluted Water ◽  
Wastewater Discharge ◽  
Metal Bioaccumulation ◽  
Water Metal

Ha Noi lakes are of great ecological interest, but they are suffering from many pollution sources, especially wastewater discharge. Aquatic organisms living, especially Oreochomic mossambicus and Labeo rohita cultured in polluted water for local consumption would pose a threat to human health. The research attempted to understand the metal accumulation in these two fish species and in Macro zooplankton (> 200 µm) living in lakes of Hanoi. Various metals showed different affinity to fish species and their tissues. Metal accumulation factors (BAF) in livers ranged from 4 to 23 is much higher than that in muscles ranged from 0.04 to 2.07. The variation of metal accumulation in fish statistically correlated to the temperature of water. Metal concentration in macrozoo plankton varied during the period of sampling. The results showed the increase in metal accumulation from lower to upper trophic levels in food webs.

scholarly journals Elevated temperature and browning increase dietary methylmercury, but decrease essential fatty acids at the base of lake food webs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pianpian Wu ◽  
Martin J. Kainz ◽  
Fernando Valdés ◽  
Siwen Zheng ◽  
Katharina Winter ◽  
...  
Keyword(s):  
Climate Change ◽  
Fatty Acids ◽  
Organic Matter ◽  
Food Webs ◽  
Essential Fatty Acids ◽  
Trophic Levels ◽  
Climate Change Scenarios ◽  
Essential Nutrients ◽  
Aquatic Food Webs ◽  
Aquatic Food

AbstractClimate change scenarios predict increases in temperature and organic matter supply from land to water, which affect trophic transfer of nutrients and contaminants in aquatic food webs. How essential nutrients, such as polyunsaturated fatty acids (PUFA), and potentially toxic contaminants, such as methylmercury (MeHg), at the base of aquatic food webs will be affected under climate change scenarios, remains unclear. The objective of this outdoor mesocosm study was to examine how increased water temperature and terrestrially-derived dissolved organic matter supply (tDOM; i.e., lake browning), and the interaction of both, will influence MeHg and PUFA in organisms at the base of food webs (i.e. seston; the most edible plankton size for zooplankton) in subalpine lake ecosystems. The interaction of higher temperature and tDOM increased the burden of MeHg in seston (< 40 μm) and larger sized plankton (microplankton; 40–200 μm), while the MeHg content per unit biomass remained stable. However, PUFA decreased in seston, but increased in microplankton, consisting mainly of filamentous algae, which are less readily bioavailable to zooplankton. We revealed elevated dietary exposure to MeHg, yet decreased supply of dietary PUFA to aquatic consumers with increasing temperature and tDOM supply. This experimental study provides evidence that the overall food quality at the base of aquatic food webs deteriorates during ongoing climate change scenarios by increasing the supply of toxic MeHg and lowering the dietary access to essential nutrients of consumers at higher trophic levels.

scholarly journals Evaluating Coexistence of Fish Species with Coastal Cutthroat Trout in Low Order Streams of Western Oregon and Washington, USA

Fishes ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 4
Author(s):  
Kyle D. Martens ◽  
Jason Dunham
Keyword(s):  
Pacific Northwest ◽  
Species Interactions ◽  
Coho Salmon ◽  
Cutthroat Trout ◽  
Single Species ◽  
The Pacific ◽  
Small Streams ◽  
Coastal Cutthroat Trout ◽  
Multiple Species ◽  
Low Order

When multiple species of fish coexist there are a host of potential ways through which they may interact, yet there is often a strong focus on studies of single species without considering these interactions. For example, many studies of forestry–stream interactions in the Pacific Northwest have focused solely on the most prevalent species: Coastal cutthroat trout. To examine the potential for interactions of other fishes with coastal cutthroat trout, we conducted an analysis of 281 sites in low order streams located on Washington’s Olympic Peninsula and along the central Oregon coast. Coastal cutthroat trout and juvenile coho salmon were the most commonly found salmonid species within these streams and exhibited positive associations with each other for both presence and density. Steelhead were negatively associated with the presence of coastal cutthroat trout as well as with coho salmon and sculpins (Cottidae). Coastal cutthroat trout most frequently shared streams with juvenile coho salmon. For densities of these co-occurring species, associations between these two species were relatively weak compared to the strong influences of physical stream conditions (size and gradient), suggesting that physical conditions may have more of an influence on density than species interactions. Collectively, our analysis, along with a review of findings from prior field and laboratory studies, suggests that the net effect of interactions between coastal cutthroat trout and coho salmon do not appear to inhibit their presence or densities in small streams along the Pacific Northwest.

Functional diversity alters the effects of a pulse perturbation on the dynamics of tritrophic food webs

2021 ◽  
Author(s):  
Ruben Ceulemans ◽  
Laurie Anne Myriam Wojcik ◽  
Ursula Gaedke
Keyword(s):  
Food Web ◽  
Food Webs ◽  
Functional Diversity ◽  
Feedback Loop ◽  
Environmental Changes ◽  
Biodiversity Loss ◽  
Trophic Levels ◽  
Nutrient Pulse ◽  
Trade Offs ◽  
Food Web Model

Biodiversity decline causes a loss of functional diversity, which threatens ecosystems through a dangerous feedback loop: this loss may hamper ecosystems' ability to buffer environmental changes, leading to further biodiversity losses. In this context, the increasing frequency of climate and human-induced excessive loading of nutrients causes major problems in aquatic systems. Previous studies investigating how functional diversity influences the response of food webs to disturbances have mainly considered systems with at most two functionally diverse trophic levels. Here, we investigate the effects of a nutrient pulse on the resistance, resilience and elasticity of a tritrophic---and thus more realistic---plankton food web model depending on its functional diversity. We compare a non-adaptive food chain with no diversity to a highly diverse food web with three adaptive trophic levels. The species fitness differences are balanced through trade-offs between defense/growth rate for prey and selectivity/half-saturation constant for predators. We showed that the resistance, resilience and elasticity of tritrophic food webs decreased with larger perturbation sizes and depended on the state of the system when the perturbation occured. Importantly, we found that a more diverse food web was generally more resistant, resilient, and elastic. Particularly, functional diversity dampened the probability of a regime shift towards a non-desirable alternative state. In addition, despite the complex influence of the shape and type of the dynamical attractors, the basal-intermediate interaction determined the robustness against a nutrient pulse. This relationship was strongly influenced by the diversity present and the third trophic level. Overall, using a food web model of realistic complexity, this study confirms the destructive potential of the positive feedback loop between biodiversity loss and robustness, by uncovering mechanisms leading to a decrease in resistance, resilience and elasticity as functional diversity declines.

MUSCLE PROTEINS OF PACIFIC SALMON (ONCORHYNCHUS): II. AN INVESTIGATION OF MUSCLE PROTEIN AND OTHER SUBSTANCES SOLUBLE IN SALT SOLUTIONS OF LOW IONIC STRENGTH BY COLUMN CHROMATOGRAPHY

1962 ◽  
Vol 40 (7) ◽  
pp. 919-927 ◽  
Author(s):  
H. Tsuyuki ◽  
E. Roberts ◽  
R. E. A. Gadd
Keyword(s):  
Sockeye Salmon ◽  
Moving Boundary ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Muscle Protein ◽  
Deae Cellulose ◽  
Ophiodon Elongatus ◽  
The Pacific ◽  
Other Substances ◽  
Low Ionic Strength

The muscle myogens and other components of the spring salmon (O. tshawytscha), chum salmon (O. keta), coho salmon (O. kisutch), and sockeye salmon (O. nerka), as well as the lingcod (Ophiodon elongatus), were separated by the use of diethylaminoethyl (DEAE) cellulose columns. Significant amounts of slowly dialyzable inosine and inosinic acid which may lead to spurious peaks in moving-boundary electrophoretic separations have been shown to be present in the muscle myogen preparations. The basic differences in the muscle myogen components of the Pacific salmon and the lingcod are compared.

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