Fisheries research

Effective management of Minnesota’s fisheries relies on access to the best available science to inform decisions. The fisheries research unit consists of researchers and support staff who work in area fisheries offices statewide.

Staff conduct applied research that evaluates management practices; develops new management tools and sampling techniques; and anticipates responses of fisheries to new and existing stressors.


Big cats inhabit the Minnesota

A large yellow perchA three-year study of Minnesota River flathead catfish between Mankato and Shakopee showed an abundant population of large fish topping 20 inches.

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Are perch getting smaller?

A large yellow perchA project designed to find out why the number of yellow perch are declining in fish population counts continues this summer in 25 Minnesota lakes.

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Monitoring shows healthier, happier trout

A trout stream winds through a valley in southeastern MinnesotaData collected as part of the DNR's ongoing long-term stream monitoring program help explain southeastern Minnesota's abundant brown trout.

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Tracking change for the future

Bear Head Lake in northern MinnesotaSince 2008, an intensive lake ecosystem monitoring program has detected and analyzed changes in key Minnesota lakes.

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Investigational reports: Minnesota DNR fisheries section publications for research studies that have more local or regional management implications.

Special publications: DNR manuals, lake management plans, guidelines or reviews.

Peer-reviewed publications: Research studies that are published in scientific journals and have gone through a rigorous peer review process. Results of these studies influence fisheries management beyond Minnesota. Copies of these reports can usually be received by contacting the author.


Fisheries research unit staff have a broad range of skills and expertise including population and fish community dynamics; bioenergetics and food web dynamics; genetics; stock assessment; statistics; fish habitat; assessment methodologies and hydroacoustics; watershed and landscape ecology; and long term monitoring.

Melissa TremlResearch managerSt. Paul
John HoxmeierResearch supervisorSt. Paul
Patrick SchmalzResearch supervisorDuluth
Tyler AhrenstorffResearch scientistBrainerd
Bethany BethkeResearch scientistDuluth
Doug DietermanResearch scientistLake City
Will FrenchLong-term monitoring biologistSt. Paul
Brian HerwigResearch scientistBemidji
Beth HolbrookResearch scientistBrainerd
Tom JonesTreaty fisheries coordinatorAitkin
Dale LogsdonResearch scientistWaterville
Tim MartinLong-term monitoring biologistSt. Paul
Mike McInernyResearch scientistGlenwood
Loren MillerResearch scientistSt. Paul
Heidi RantalaResearch scientistDuluth
Jeff ReedResearch scientistGlenwood
Casey SchoenebeckResearch scientistGlenwood
Steve ShroyerResearch scientistWaterville
David StaplesBiometricianSt. Paul
Colleen TelanderResearch office administrative assistantSt. Paul

Melissa Treml, fisheries research manager, St. Paul
[email protected]
tel. 651-259-5231
fax 651-297-4916