Fish infected with VEN appear less resistant to environmental stress. There are currently more than 90 ponds in Maine that anadromous alewives have access to via fish passages or stocking. There have been no documented cases of game fish mortality due to VEN . VEN has not been found in sea-run juvenile alewives in the freshwater environment or elsewhere in Maine . VEN is not a disease of regulatory concern to the State of Maine.
Thiamin deficiency can occur in trout and salmon that feed extensively on landlocked ale-wives .
This phenomenon has not occurred in lakes where sea-run alewives occur . It is alleged that alewives consume the majority of large zooplankton at the expense of fresh-water fish species. Therefore, lake productivity can accommodate alewives and freshwater species. There are over 90 lakes and ponds in Maine where sea-run alewives coexist with healthy populations of freshwater fish species. In two studies done by the Maine DEP , data indicated that alewives did not significantly alter water quality.