scholarly journals Sediment respiration drives circulation and production of CO2 in ice-covered Alaskan arctic lakes

2018 ◽  
Vol 3 (3) ◽  
pp. 302-310 ◽  
Author(s):  
Sally MacIntyre ◽  
Alicia Cortés ◽  
Steven Sadro
Keyword(s):  
Arctic Lakes ◽  
Sediment Respiration ◽  
Alaskan Arctic

Epipelic and pelagic primary production in Alaskan Arctic lakes of varying depth

Hydrobiologia ◽  
2008 ◽  
Vol 614 (1) ◽  
pp. 243-257 ◽  
Author(s):  
Stephen C. Whalen ◽  
Brian A. Chalfant ◽  
Eric N. Fischer
Keyword(s):  
Primary Production ◽  
Arctic Lakes ◽  
Alaskan Arctic

scholarly journals Comparison of Fatty Acid Contents in Major Lipid Classes of Seven Salmonid Species from Siberian Arctic Lakes

Biomolecules ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 419 ◽  
Author(s):  
Nadezhda N. Sushchik ◽  
Olesia N. Makhutova ◽  
Anastasia E. Rudchenko ◽  
Larisa A. Glushchenko ◽  
Svetlana P. Shulepina ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Natural Populations ◽  
Arctic Lakes ◽  
Lipid Classes ◽  
Total Lipids ◽  
Omega 3 ◽  
Intrinsic Factors ◽  
Siberian Arctic ◽  
Similar Content ◽  
Valuable Compounds

Long-chain omega-3 polyunsaturated fatty acids (LC-PUFA) essential for human nutrition are mostly obtained from wild-caught fish. To sustain the LC-PUFA supply from natural populations, one needs to know how environmental and intrinsic factors affect fish fatty acid (FA) profiles and contents. We studied seven Salmoniformes species from two arctic lakes. We aimed to estimate differences in the FA composition of total lipids and two major lipid classes, polar lipids (PL) and triacylglycerols (TAG), among the species and to evaluate LC-PUFA contents corresponding to PL and TAG in muscles. Fatty acid profiles of PL and TAG in all species were characterized by the prevalence of omega-3 LC-PUFA and C16-C18 monoenoic FA, respectively. Fish with similar feeding spectra were identified similarly in multivariate analyses of total lipids, TAG and PL, due to differences in levels of mostly the same FA. Thus, the suitability of both TAG and total lipids for the identification of the feeding spectra of fish was confirmed. All species had similar content of LC-PUFA esterified as PL, 1.9–3.5 mg g−1, while the content of the TAG form strongly varied, from 0.9 to 9.8 mg g−1. The LC-PUFA-rich fish species accumulated these valuable compounds predominately in the TAG form.

scholarly journals Assessing the utility of sulfur isotope values for understanding mercury concentrations in water and biota from high Arctic lakes

2019 ◽  
Vol 5 (2) ◽  
pp. 90-106 ◽  
Author(s):  
Gretchen L. Lescord ◽  
Meredith G. Clayden ◽  
Karen A. Kidd ◽  
Jane L. Kirk ◽  
Xiaowa Wang ◽  
...  
Keyword(s):  
Food Webs ◽  
Total Mercury ◽  
Nitrogen Isotopes ◽  
Sulfur Isotopes ◽  
High Arctic ◽  
Arctic Lakes ◽  
Carbon And Nitrogen ◽  
Resolute Bay ◽  
Aquatic Food ◽  
Globally Stable

Methylmercury (MeHg) biomagnifies through aquatic food webs resulting in elevated concentrations in fish globally. Stable carbon and nitrogen isotopes are frequently used to determine dietary sources of MeHg and to model its biomagnification. However, given the strong links between MeHg and sulfur cycling, we investigated whether sulfur isotopes (δ34S) would improve our understanding of MeHg concentrations ([MeHg]) in Arctic lacustrine food webs. Delta34S values and total mercury (THg) or MeHg were measured in water, sediments, and biota from six lakes near Resolute Bay, NU, Canada. In two lakes impacted by historical eutrophication, aqueous sulfate δ34S was ∼8‰ more positive than sedimentary δ34S, suggestive of bacterial sulfate reduction in the sediment. In addition, aqueous δ34S showed a significant positive relationship with aqueous [MeHg] across lakes. Within taxa across lakes, [THg] in Arctic char muscle and [MeHg] in their main prey, chironomids, were positively related to their δ34S values across lakes, but inconsistent relationships were found across entire food webs among lakes. Across lakes, nitrogen isotopes were better predictors of biotic [THg] and [MeHg] than δ34S within this dataset. Our results suggest some linkages between Hg and S biogeochemistry in high Arctic lakes, which is an important consideration given anticipated climate-mediated changes in nutrient cycling.

A new Clitocybe from the Alaskan Arctic

1976 ◽  
Vol 54 (9) ◽  
pp. 976-980 ◽  
Author(s):  
Gary A. Laursen ◽  
Orson K. Miller Jr. ◽  
Howard E. Bigelow
Keyword(s):  
New Species ◽  
Beach Ridges ◽  
Microscopic Features ◽  
Alaskan Arctic ◽  
A New Species ◽  
High Center

A new species of Clitocybe is described from the Alaskan Arctic. This agaric grows on low-center polygon rims, high-center polygons, and on beach ridges. Drawings of microscopic features and macrophotographs are included.

scholarly journals Climate and permafrost effects on the chemistry and ecosystems of High Arctic Lakes

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
K. E. Roberts ◽  
S. F. Lamoureux ◽  
T. K. Kyser ◽  
D. C. G. Muir ◽  
M. J. Lafrenière ◽  
...  
Keyword(s):  
High Arctic ◽  
Arctic Lakes

CHIRONOMIDAE (DIPTERA) OF CHAR LAKE, CORNWALLIS ISLAND, N.W.T., WITH DESCRIPTIONS OF TWO NEW SPECIES

1976 ◽  
Vol 108 (10) ◽  
pp. 1053-1064 ◽  
Author(s):  
D. R. Oliver
Keyword(s):  
New Species ◽  
Arctic Lakes ◽  
Additional Species ◽  
Two New Species ◽  
Cornwallis Island ◽  
New Distribution ◽  
Pharate Adult ◽  
Chironomid Fauna

AbstractPseudodiamesa arctica (Mall.), Heterotrissocladius subpilosus (Kieff.), Orthocladius (s.s.) lapponicus Goetgh., Orthocladius (s.s.) sp., Paracladius quadrinodosus Hirv., Trissocladius tricornis n. sp., and Lauterbornia sedna n. sp. develop from egg to pharate adult in Char Lake. The occurrence of the larvae of 7 additional species is apparently adventitious, All stages of the two new species plus the larvae of P. arctica and P. quadrinodosus are described. The males of T. tricornis are dimorphic and L. sedna is parthenogenetic. New distribution records are given for most of the species. The chironomid fauna of Char Lake is compared with that of other arctic lakes.

Homeostatic Characteristics of Single Species Fish Stocks in Arctic Lakes

1983 ◽  
Vol 40 (7) ◽  
pp. 987-1024 ◽  
Author(s):  
Lionel Johnson
Keyword(s):  
Stock Returns ◽  
Dominant Species ◽  
Size Structure ◽  
Arctic Charr ◽  
Arctic Lakes ◽  
Large Individual ◽  
Total Biomass ◽  
Length Frequency ◽  
Initial State ◽  
Fish Stocks

The results of investigations on the fish stocks of seven Arctic lakes covering a period of 23 yr are described. These lakes have remained largely undisturbed since their formation in late glacial times; all but one are completely autonomous and of comparatively small size. Such lakes provide a unique opportunity for the development and testing of conceptual models. In all cases the only fish species present is Arctic charr, Salvelinus alpinus. Length frequency distributions derived from gillnet catch curves are shown to be, within reasonable limits, representative of the actual populations in the lake, and not artifacts of the sampling procedure. Length frequency curves show a unimodal or bimodal distribution and this structure, in the absence of perturbation, appears to remain constant indefinitely. Individuals are of great age but age-at-length is highly variable. Age and size structure are shown to be comparable with the age and size structure of the dominant tree species in a climax forest; it is concluded that forces of great generality fashion these configurations. It is hypothesized that all species tend to move towards a state of least energy dissipation; this can be most readily seen in the dominant species at the climax in an autonomous system. The dominant species is characterized by large individual size, a high degree of uniformity, high total biomass, great mean age, indeterminate age-at-death, and a low incidence of replacement stock. After severe perturbation it is shown that the charr stock returns to a state of least dissipation without oscillation. Absence of oscillation during the return to the initial state, combined with the long-term stability shown in control lakes, indicates the presence of an effective damping mechanism; this in turn indicates the existence of organization within the stock as a whole. Organization develops through an interactive mechanism described under the doctrine of homeokinesis, which is responsible for energy equipartitioning and the maintenance of uniformity. These concepts help to explain phenomena observed in more complex systems and help our understanding of ecosystem functioning.

Arctic Lakes and Streams as Gas Conduits to the Atmosphere: Implications for Tundra Carbon Budgets

Science ◽  
1991 ◽  
Vol 251 (4991) ◽  
pp. 298-301 ◽  
Author(s):  
G. W. KLING ◽  
G. W. KIPPHUT ◽  
M. C. MILLER
Keyword(s):  
Arctic Lakes ◽  
Carbon Budgets
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