Comparing total mercury concentrations of northern Dolly Varden, Salvelinus malma malma, in two Canadian Arctic rivers 1986–1988 and 2011–2013

Polar Biology ◽  
2019 ◽  
Vol 42 (5) ◽  
pp. 865-876
Author(s):  
L. Tran ◽  
J. D. Reist ◽  
C. P. Gallagher ◽  
M. Power
Keyword(s):  
Total Mercury ◽  
Canadian Arctic ◽  
Dolly Varden ◽  
Salvelinus Malma ◽  
Dolly Varden Salvelinus Malma ◽  
Northern Dolly Varden ◽  
Arctic Rivers

Life-history characteristics and landscape attributes as drivers of genetic variation, gene flow, and fine-scale population structure in northern Dolly Varden (Salvelinus malma malma) in Canada

2015 ◽  
Vol 72 (10) ◽  
pp. 1477-1493 ◽  
Author(s):  
Les N. Harris ◽  
Robert Bajno ◽  
Colin P. Gallagher ◽  
Itsuro Koizumi ◽  
Lucy K. Johnson ◽  
...  
Keyword(s):  
Population Structure ◽  
Genetic Variation ◽  
Life History ◽  
Gene Flow ◽  
Isolation By Distance ◽  
Dolly Varden ◽  
Salvelinus Malma ◽  
Dolly Varden Salvelinus Malma ◽  
Northern Dolly Varden ◽  
Population Demographic

The northern Dolly Varden (Salvelinus malma malma) displays variable life-history types and occupies freshwater habitats with varying levels of connectivity. Here, we assayed microsatellite DNA variation in northern Dolly Varden from the western Canadian Arctic to resolve landscape and life-history variables driving variation in genetic diversity and population structure. Overall, genetic variation was highest in anadromous populations and lowest in those isolated above waterfalls, with stream-resident forms intermediate between the two. Anadromous and isolated populations were genetically divergent from each other, while no genetic differentiation was detectable between sympatric anadromous and stream-resident forms. Population structure was stable over 25 years, hierarchically organized, and conformed to an isolation-by-distance pattern, but stream-isolated forms often deviated from these patterns. Gene flow occurred primarily among Yukon North Slope populations and between sympatric anadromous and resident forms. These results were sex-dependent to some extent, but were influenced more by reproductive status and life history. Our study provides novel insights into the life history, population demographic, and habitat variables that shape the distribution of genetic variation and population structure in Arctic fluvial habitats while providing a spatial context for management and conservation.

Summer growth patterns of northern Dolly Varden (Salvelinus malma) smolts from the Prudhoe Bay region of Alaska

1997 ◽  
Vol 54 (5) ◽  
pp. 1103-1110 ◽  
Author(s):  
R G Fechhelm ◽  
J D Bryan ◽  
W B Griffiths ◽  
L R Martin
Keyword(s):  
Prey Availability ◽  
Late Summer ◽  
Early Summer ◽  
Growth Patterns ◽  
Dolly Varden ◽  
Salvelinus Malma ◽  
Dolly Varden Salvelinus Malma ◽  
Northern Dolly Varden ◽  
Stock Mixing ◽  
Rates Of Growth

Summer length growth patterns of northern Dolly Varden (Salvelinus malma) smolts from the Sagavanirktok River, northern Alaska, were analyzed for the years 1985-1994 and found to be sigmoidal, indicating slow rates of growth in early and late summer with the most rapid growth occurring in midseason. Nonlinear logistic regression functions of mean cohort length against date provided a reasonable fit of the data for all years except for 1991, accounting for more than 94% (r2 values ranged from 0.95 to 0.99) of the variation in mean daily length in any given year. Slow growth in early summer is in direct contrast with the growth patterns reported for juvenile broad whitefish (Coregonus nasus) and Arctic cisco (C. autumnalis) which inhabit the Sagavanirktok River and estuary. Some possible explanations for the observed Dolly Varden growth patterns include migration, dispersal, prey availability, water quality, and stock mixing.

Genetic analysis of Dolly Varden (Salvelinus malma) across its North American range: evidence for a contact zone in southcentral Alaska

2015 ◽  
Vol 72 (7) ◽  
pp. 1048-1057 ◽  
Author(s):  
Eric B. Taylor ◽  
Shannan L. May-McNally
Keyword(s):  
Contact Zone ◽  
North American ◽  
Salvelinus Alpinus ◽  
Glacial Refugia ◽  
Bull Trout ◽  
Dolly Varden ◽  
Salvelinus Malma ◽  
Genetic Lineages ◽  
Dolly Varden Salvelinus Malma ◽  
Northern Dolly Varden

Contact zones between divergent lineages of aquatic taxa have been described from the northeastern Pacific Ocean. We surveyed samples of Dolly Varden (Salvelinus malma) from their North American range for variation at 14 microsatellite DNA loci. After accounting for hybridization between Dolly Varden and co-occurring bull trout (Salvelinus confluentus) and Arctic char (Salvelinus alpinus), we found evidence for two genetic lineages of Dolly Varden consistent with the previously recognized subspecies, northern Dolly Varden (S. m. malma) and southern Dolly Varden (S. m. lordii). We documented a contact zone between the two subspecies from the eastern Alaska Peninsula to Cook Inlet, Alaska, where admixture values (i.e., the proportion of the genome estimated to be composed of northern Dolly Varden, QNDV) ranged between QNDV = 0.245 and 0.754 across about 700 ocean kilometres. Populations of Dolly Varden showing low admixture (i.e., less than 5%) were located a minimum of 346 km to the west to 1200 km to the southeast, respectively, from the contact zone. The two lineages of Dolly Varden probably stem from isolation and subsequent divergence in, and dispersal from, distinct northern and southern Pleistocene glacial refugia and substantiate the treatment of S. malma as two subspecies and as at least two designatable units under Canada’s Species at Risk Act.

Fecundity of Resident and Anadromous Dolly Varden (Salvelinus malma) in Southeastern Alaska

1973 ◽  
Vol 30 (4) ◽  
pp. 543-548 ◽  
Author(s):  
R. F. Blackett
Keyword(s):  
Egg Size ◽  
Fish Length ◽  
Dolly Varden ◽  
Salvelinus Malma ◽  
Ovary Weight ◽  
Dolly Varden Salvelinus Malma ◽  
Egg Number ◽  
Unit Of Length ◽  
The Right ◽  
Linear Regressions

Fecundity of resident Dolly Varden (Salvelinus malma) in an isolated population of southeastern Alaska averaged 66 eggs per female in comparison with 1888 eggs for anadromous Dolly Varden from two nearby streams. A relatively large egg size, averaging 3.6 mm in diameter and overlapping the range for the anadromous char, has been retained by the females in the resident population. Curvilinear regressions between egg number and fish length and linear regressions between egg number and body and ovary weights show that resident females have fewer eggs per unit of length, approximately the same number of eggs per gram of body weight, and more eggs per gram of ovary weight than anadromous females. The resident char attain sexual maturity a year earlier in life and at a smaller size than the migratory char. Development of a larger left ovary containing more eggs than the right was a common occurrence for both resident and anadromous Dolly Varden.

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