Linking oceanic food webs to coastal production and growth rates of Pacific salmon (Oncorhynchus spp.), using models on three scales

Outbreeding is a potential genetic risk in Pacific salmon (Oncorhynchus spp.) when aquaculture practices introduce nonnative domesticated fish to wild environments, making interbreeding with wild populations possible. In this study, F1 and F2 hybrid families of coho salmon (Oncorhynchus kisutch) were created using a captive freshwater aquaculture strain and a locally derived hatchery population that is integrated with naturally spawning fish. Intermediate growth was detected in F1 and F2 hybrids from crosses reared in captivity; both generations had mean weight and length values between those of the parent populations after their first year (p < 0.05). In the early life history stages, maternal effects increased alevin growth in progeny of hatchery dams relative to those of captive dams (p < 0.001). Aquaculture control families showed greater growth rates than hybrids in late summer of their 1st year and in the following spring (p < 0.05), while the hatchery controls had lower growth rates during the first summer (p < 0.05). Line cross analysis indicated that changes in additive and dominance interactions, but not unfavorable epistatic interactions, likely explain the differences in weight, length, and growth rate observed in hybrids of these stocks of coho salmon.

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Seasonal relative influence of food quantity, quality, and feeding behaviour on zooplankton growth regulation in coastal food webs

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315409990804 ◽

2009 ◽

Vol 90 (6) ◽

pp. 1189-1201 ◽

Cited By ~ 17

Author(s):

C.A. Vargas ◽

R.A. Martínez ◽

R. Escribano ◽

N.A. Lagos

Keyword(s):

Food Webs ◽

Growth Rates ◽

Feeding Behaviour ◽

Growth Regulation ◽

Critical Factor ◽

Multiple Regression Model ◽

Trophic Levels ◽

Relative Influence ◽

Natural Occurrence ◽

Food Quantity

In aquatic food webs zooplankton constitutes an important link between primary producers and higher trophic levels. Copepods often dominate the zooplankton in coastal oceans and are the prey of the majority of planktivorous fish. Feeding behaviour, as well as the food quantity and quality are recognized factors that affect copepod growth, and therefore, the energy transfer efficiency throughout food webs. The natural occurrence and magnitude of these growth factors and their combined effects on marine copepods, as keystone grazers in the pelagic marine realm, are poorly understood. Here, we assessed how these different factors vary throughout the year, and then examine their relative influence upon copepods maximal growth rates. A multiple regression model, including all variables previously selected, and the inclusion of the sea temperature allowed us to estimate the pure influence of the studied factors, and the environmental effect on copepod growth rates. The results imply that ingestion of diatoms may induce a positive effect on specific growth rates of copepods, and the quality of this food item (high PUFA and HUFA availability) might explain such effect. Therefore, seasonal variability in diatom abundance, possibly driven by changes in the oceanographic regime, should be considered a critical factor controlling copepod growth in productive coastal ecosystems.

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Pesticides, aquatic food webs, and the conservation of Pacific salmon

Frontiers in Ecology and the Environment ◽

10.1890/090142 ◽

2010 ◽

Vol 8 (9) ◽

pp. 475-482 ◽

Cited By ~ 43

Author(s):

Kate H Macneale ◽

Peter M Kiffney ◽

Nathaniel L Scholz

Keyword(s):

Food Webs ◽

Pacific Salmon ◽

Aquatic Food Webs ◽

Aquatic Food

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Models of the effects of marine-derived nutrients on salmon (Oncorhynchus spp.) population dynamics

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f09-161 ◽

2010 ◽

Vol 67 (1) ◽

pp. 5-15 ◽

Cited By ~ 4

Author(s):

Milo D. Adkison

Keyword(s):

Population Dynamics ◽

Mathematical Models ◽

Fresh Water ◽

Growth Rates ◽

Pacific Salmon ◽

Food Resources ◽

Juvenile Salmon ◽

Management Implications ◽

Freshwater Habitats ◽

Stock Recruitment

Pacific salmon ( Oncorhynchus spp.) populations transfer large quantities of nutrients from their marine to their freshwater habitats. These nutrients have been shown to affect salmon populations in fresh water, including increasing basal food resources and elevating juvenile salmon growth rates and condition. The broader effects on recruitment and commercial harvests, however, are not clear. I developed and explored mathematical models of the effects of these nutrients on stock–recruitment relationships and used these models to investigate management implications. Populations strongly dependent on nutrients had lower sustained yields than those not dependent on nutrients. When nutrients strongly affected the stock–recruitment relationship, relatively low harvest rates and high escapement levels were necessary to maintain the population’s productivity. However, in some scenarios, the highest yields were obtained from small, nutrient-depleted populations. In other scenarios, the nutrient dependence had few management implications.

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Effects of subsidies from small anadromous Pacific salmon populations on stream and riparian food webs are mediated by channel gradient

Freshwater Science ◽

10.1086/712605 ◽

2020 ◽

pp. 000-000

Author(s):

Jessie A. Moravek ◽

Hannah L. Clipp ◽

Thomas P. Good ◽

Peter M. Kiffney

Keyword(s):

Food Webs ◽

Pacific Salmon

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Luciferin production and luciferase transcription in the bioluminescent copepod Metridia lucens

PeerJ ◽

10.7717/peerj.5506 ◽

2018 ◽

Vol 6 ◽

pp. e5506 ◽

Cited By ~ 2

Author(s):

Michael Tessler ◽

Jean P. Gaffney ◽

Jason M. Crawford ◽

Eric Trautman ◽

Nehaben A. Gujarati ◽

...

Keyword(s):

Mass Spectrometry ◽

Food Webs ◽

Molecular Basis ◽

Common Species ◽

Gene Set ◽

Marine Zooplankton ◽

Light Production ◽

Feeding Experiments ◽

Paralog Gene ◽

Oceanic Food Webs

Bioluminescent copepods are often the most abundant marine zooplankton and play critical roles in oceanic food webs. Metridia copepods exhibit particularly bright bioluminescence, and the molecular basis of their light production has just recently begun to be explored. Here we add to this body of work by transcriptomically profiling Metridia lucens, a common species found in temperate, northern, and southern latitudes. In this previously molecularly-uncharacterized species, we find the typical luciferase paralog gene set found in Metridia. More surprisingly, we recover noteworthy putative luciferase sequences that had not been described from Metridia species, indicating that bioluminescence produced by these copepods may be more complex than previously known. This includes another copepod luciferase, as well as one from a shrimp. Furthermore, feeding experiments using mass spectrometry and 13C labelled L-tyrosine and L-phenylalanine firmly establish that M. lucens produces its own coelenterazine luciferin rather than acquiring it through diet. This coelenterazine synthesis has only been directly confirmed in one other copepod species.

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Sex-Related Parental Influences on Early Development of Pacific Salmon

Journal of the Fisheries Research Board of Canada ◽

10.1139/f70-249 ◽

1970 ◽

Vol 27 (12) ◽

pp. 2197-2214 ◽

Cited By ~ 6

Author(s):

F. C. Withler ◽

R. B. Morley

Keyword(s):

Early Development ◽

Growth Rates ◽

Chum Salmon ◽

Pacific Salmon ◽

Female Parent ◽

Single Species ◽

Male Parent ◽

Parental Influences ◽

Interspecific Crosses ◽

Parental Origin

Among the fertilized eggs arising from a series of intraspecific and interspecific crosses involving sockeye, pink, and chum salmon, time from fertilization to hatching was longest for crosses involving sockeye males, less for those involving pink males, and least for those involving chum males. For crosses of females of the three species with males of a single species, eggs from pink females took longest to hatch, those from sockeye females took less time, and those of chums took the least. Larva size at hatching was greatest for larvae emerging from chum eggs, irrespective of male parent, less for those emerging from sockeye eggs, and least for those from pink eggs. There were only small differences in the size of larvae at hatching from the eggs of females of one species that had been fertilized by males of each of the three species. Among the pre-hatched embryos developing in eggs of a single species, those with a sockeye male parent grew slowest, those with a pink male parent grew faster, and those involving a chum male parent fastest. In eggs from females of the three species fertilized by the males of one species, embryos in eggs of chum females grew fastest, those in eggs of sockeye females slower, and those in eggs of pink females slowest. Gross malformation among hybrid offspring was not pronounced — only chum male × sockeye female and chum male × pink female hybrids displayed markedly greater proportions of malformed individuals than did the combined intraspecific crosses involving the same parents. It is possible that observed differences in time from fertilization to hatching between eggs of different parental origin are brought about by the interaction of growth rates inherited mainly from the male parents and a critical embryo size related to the size of eggs of the female parent. Identification of parental determinants of early development of salmon should make it possible to create salmon forms capable of exploiting new or changed environments.

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Ease into Climate Change Instruction through Ocean Acidification

The American Biology Teacher ◽

10.1525/abt.2021.83.4.247 ◽

2021 ◽

Vol 83 (4) ◽

pp. 247-253

Author(s):

David C. Owens ◽

Susanne Rafolt ◽

Erin M. Arneson

Keyword(s):

Climate Change ◽

Calcium Carbonate ◽

Ocean Acidification ◽

Food Webs ◽

Fossil Fuels ◽

Food Resources ◽

Atmospheric Co2 ◽

Anthropogenic Sources ◽

Oceanic Food Webs ◽

Sources Of Co2

Although climate change garners the bulk of headlines, ocean acidification is an equally important issue that also results from our increasing consumption of fossil fuels. As atmospheric CO2 dissolves into the ocean, the ocean’s pH decreases, making it increasingly difficult for organisms that build calcium carbonate skeletons to grow and thrive. Given that these marine calcifiers – such as corals, snails, shellfish, crustaceans, and plankton – often form the base of oceanic food webs and are habitat and food resources for larger oceanic plants and animals (including humans), ocean acidification poses a serious threat. In this article, we present a series of investigations that provide evidence that increases in anthropogenic sources of CO2 contribute to the acidification of the ocean, and that an increasingly acidic ocean can negatively impact marine calcifiers.

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