THE HOMOGENIZING OF MINNESOTA LAKE FISH ASSEMBLAGES

The loss of unique fish assemblages in Minnesota lakes was evaluated b y comparing species presence in historical and most-recent surveys of both stocked and unstocked lakes. Fish stocking resulted in greater sp ecies richness but reduced fish assemblage diversity among stocked lak es. No significant changes occurred among unstocked lakes. Short-term goals of additional fishing opportunities were partially achieved thro ugh stocking by creating more opportunities to fish for walleye in mor e lakes. However, the resulting loss of fish assemblage diversity with in a local management area was apparently not considered. Fisheries ma nagers should consider the potential for loss of community diversity a nd preserve unique fish communities where they still exist.