 The annual average discharge is , varying from .The river holds anadromous Atlantic salmon ("Salmo salar"), brook trout ("Salvelinus fontinalis"), and less commonly American eel ("Anguilla rostrata") and three-spined stickleback ("Gasterosteus aculeatus").There are also alewife ("Alosa pseudoharengus"), Atlantic tomcod ("Microgadus tomcod") and rainbow smelt ("Osmerus mordax").