Using scale samples or fin clips we are able to extract DNA without causing the fish any harm. Portions of the DNA are then amplified to create a “DNA fingerprint” which is a genetic signature for that individual. We are using this technique to assess fish population genetics in the following studies.
Walleye: Genetic Influence of stocked walleye in the St. Mary’s River (Dave Caroffino)
Walleye were sampled at four current spawning locations within the St. Mary’s River (Waiska River, Munuscong Bay, Potogannissing River, and Bar River) and samples were also obtained from a historic (pre-stocking) population (Charlotte River). The DNA extracted from these fish was used to determine if the stocking of Bay de Noc or Manistique Lake walleye had achieved the desired result of contributing to the natural reproduction of the St. Marys River walleye population. We were unable to detect a clear difference between the success of stocking from Manistique Lake or Bay de Noc. Neither population was genetically similar to a current spawning population across all loci, nor was one more closely related to the spawning populations than another. Given the stocking history of the St. Marys River, this result merits further investigation. It would appear that the Bar River spawning population is still strictly a native run, and it may warrant a management strategy separate from other walleye populations. We are currently using this data base as a reference for assigning young of the year walleye to a particular population, as well as assigning walleye sampled in the current EPA river survey.
Funding: Edison Sault Electric Co. and Saginaw Bay Walleye Club grants to David Caroffino
Chinook:Pink Salmon Hybrids
Assymetric hybridization of pink and Chinook salmon in the St. Mary’s River (Dustin Everitt).
Natural hybridization between pink and Chinook salmon (pinooks) has only been observed in the Great lakes. To assess any pattern to the matings resulting in these hybrids, we looked at mitochondrial DNA (mtDNA) which is only inherited maternally. From 1998-2002, fifty natural pinook hybrids were caught as part of the annual salmon population surveys. After DNA extraction and mtDNA analysis, all fifty hybrids were found to have Chinook salmon mtDNA. Therefore the hybrids are a result of matings between female Chinook and male pink salmon resulting from reduced spatial and temporal segregation between species or perhaps behavioral and physiological factors.
Funding: National Science Foundation-MRI grant to Barbara Evans and Nancy Kirkpatrick
Assessing Brook Trout Populations in the Ottawa National Forest (Brian Wesolek)
Hatchery-developed strains of brook trout from wild parents have been stocked into many streams. Determining the success of these stocking efforts is being attempted using DNA techniques. Genetic material was collected from fin samples of fish at nine locations in the Ottawa National Forest (ONF), including the Jumbo River, Birch River, Walton Creek, Two Mile Creek, and State Creek. Genetic information not only reveals the origin of a fish, but also the probable origin of its parents. This information helps identify “genetically isolated” brook trout populations. For example, is there “gene flow” between brook trout that live in rivers and those that live in Lake Superior, and do migration barriers affect the success of brook trout, their growth rates, and consequently, the “flow of genes” between populations?
Funding: USDA-US Forest Service Cost Share grant to Barbara Evans and Jerry Edde (ONF)
Yellow Perch: Characterizing Yellow Perch Genetic Variability in the St. Mary’s River (Alex Mwai)
In recent years, yellow perch populations have declined in the St. Mary’s river. As part of an attempt to restore this species’ abundance, we are interested to understand the genetic variability of the remaining stocks. Are there isolated unique populations such as appears to be the case in walleye, or are the St. Mary’s yellow perch more or less homogenous We are examining yellow perch scale samples from the St. Mary’s river 2002 survey to assess the variation present in the “DNA fingerprint”. We are also examining samples from an isolated population in Soldier Lake as well as from fish collected in the EPA river survey.
Funding: EPA-GLNPO grant to LSSU Biology and Chemistry departments