Straying and population genetic structure

Mork, J.

doi:10.1111/are.1994.25.s2.93

Cited by 4 publications

(3 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The high allelic diversity at GMO132 in this stock could not have been maintained if the effective population size was low enough to explain by genetic drift the intercohort allele frequency variation in Pan I. Moreover, using a multiallelic version of the simulation software developed by Mork (1994) and the observed allele frequencies at GMO132 (which were very skewed with many low‐frequency alleles), we found that the 30 alleles observed would be reduced to on average seven alleles (range 5–9 in 20 iterations) after only four generations (our sampling time span) if N e was 23 individuals. In this context it is, however, important to mention the possibility of a low N e : N ratio, due to large variance in reproductive success, which could be expected in a highly fecund species (Hedgecock 1994; Hauser et al .…”

Section: Discussionmentioning

confidence: 99%

Selection‐induced variation at the pantophysin locus (PanI) in a Norwegian fjord population of cod (Gadus morhuaL.)

Karlsson¹,

Mork²

2003

Molecular Ecology

Self Cite

View full text Add to dashboard Cite

A total of 1290 cod (Gadus morhua L.), sampled between 1985 and 1999 from a spawning area in the Trondheimsfjord, Norway, were assayed for the nuclear-encoded locus PanI (pantophysin). The majority of samples were taken during the spawning season at two nearby sampling locations at depths of 100 and 60 m, respectively. Genetic analysis revealed significant effects of cohort, sex and sampling location on allele frequencies at PanI. The contribution of each of these three factors to the total among-sample diversity (FST) of 8.01% at PanI was estimated to be 3.78, 2.55 and 1.68%, respectively. Sign tests revealed a significant excess of heterozygotes at both sampling locations in females; a significant excess of heterozygotes in males was observed at one of the localities. Mutation, genetic drift and immigration do not appear to contribute significantly to the observed genetic heterogeneity at PanI, leaving natural selection as the main explanatory factor for the Hardy-Weinberg imbalance. The dynamics of the selection at PanI appear to be complex. Analysis of age, sex and cohort proved crucial to disentangle putative explanatory factors from their secondary effects.

show abstract

Section: Discussionmentioning

confidence: 99%

Selection‐induced variation at the pantophysin locus (PanI) in a Norwegian fjord population of cod (Gadus morhuaL.)

Karlsson¹,

Mork²

2003

Molecular Ecology

Self Cite

View full text Add to dashboard Cite

show abstract

“…It likely occurs in dourada, like it does in the well-studied Salmonidae and in many other highly migratory families of fish (Lucas and Baras, 2001;Jonsson et al, 2003). Also, dourada seem to be composed of a single genetic stock along the main stem (Batista et al, 2004), which is the situation expected when the frequency of straying is high (Mork, 1994;Bohonak, 1999).…”

Section: Upstream Fishway For Young Fishmentioning

confidence: 92%

Migratory fishes of Brazil: Life history and fish passage needs

Godinho

Kynard

2008

River Research & Apps

View full text Add to dashboard Cite

Many of the most important commercial and recreational species of the megadiverse Brazilian freshwater fishes migrate in rivers among essential habitats during all life stages. These movements, however, have been severely blocked by hundreds of hydroelectric dams and reservoirs and they will be even more obstructed due to hundreds of new developments. Fishways have been used in many countries to allow fish to pass around dams. Fishway construction is booming in Brazil, but poor understanding of migrations by Brazilian fishes has led legislators, scientists, and the public to several misconceptions about the rules of fishways in fisheries conservation. First, is a belief that fishways are only needed to facilitate upstream spawning migrations. Also, it has been suggested that upstream passage for Neotropical migrant fishes is not useful if there is no large free-flowing stretch upstream of a dam that contains spawning habitat and has a large natural floodplain (nursery habitat). In this paper, we discuss that, in addition to providing passage for pre-spawning migrants, upstream fishways also provide passage for other fish migrations (e.g. foraging), and that all up-and downstream migrations during life history need to be addressed at dams to conserve fish resources. We also argue that an upstream fishway is important even if the upstream reach does not have spawning or nursery habitats. In addition, we discuss the need for protection of downstream migrant fish, and the importance of fish behaviourists and engineers working together on fishway design and operation to solve fish passage issues.

show abstract

“…10 On these grounds, Mork considered it sensible to conclude that the negative correlation between oil price movements and macroeconomic growth represented a causal link from oil prices to aggregate economic activity. 11 However, other authors such as Wellink and Hunt, Isard and Laxton have recognized the existence of a causal link from macroeconomic performance to oil prices. 12 In addition, an important group of researchers has documented that the negative correlation between oil prices and economic activity is asymmetric.…”

Section: Us Energy Policy Before 11 September 2001mentioning

confidence: 99%

Straying and population genetic structure

Cited by 4 publications

References 4 publications

Selection‐induced variation at the pantophysin locus (PanI) in a Norwegian fjord population of cod (Gadus morhuaL.)

Selection‐induced variation at the pantophysin locus (PanI) in a Norwegian fjord population of cod (Gadus morhuaL.)

Migratory fishes of Brazil: Life history and fish passage needs

Energy markets, US energy policy, and the terrorist attacks of 11 September 2001

Contact Info

Product

Resources

About