Brett Alger, MS Student

Measuring anthropogenic disturbances in hydrogeomorphic-based lake classes using fish assemblages in 360 north-temperate lakes


The Problem

  • Hydrogeomorphic features and anthropogenic disturbances affect lake fish assemblages at multiple spatial scales across the landscape.
  • Most research and management has been done at very local scales, either by fish species or by water body.
  • We need a lake classification that groups lakes into homogenous classes according to the relationship between hydrogeomorphic, map-based landscape features (available for all lakes) and lake fish assemblages. This classification will allow us to extrapolate results from sampled lakes to those that are unsampled, which can also improve management decisions.
  • Our understanding of variation among lake fish assemblages would be vastly improved if we understood how human disturbance affects lake fish assemblages within and across groups of naturally similar lakes.

Research Question

  • What natural lake and landscape features best classify fish species richness?
  • How do anthropogenic disturbances affect fish species richness within a hydrogeomorphic-based lake classification?


  • Fish species richness and natural and anthropogenic landscape data for 360 north-temperate lakes (from ME to WI).
  • Classification and Regression Tree Analysis (CART) to classify lakes.
  • Linear regression to measure the effects of anthropogenic disturbances on lake classes.


  • Lyman Briggs College Teaching Assistantship
  • Department of Fisheries and Wildlife Teaching Fellowship
  • College of Agriculture and Natural Resources Thesis Completion Fellowship

Current Employment

NOAA – National Marine Fisheries Service