Goverment will most likley post notices if a heavily fished/utilised lake is polluted. remote lakes probably wouldnt recive notices but then again if the lake is remote theres probably nothing to polute it. the only lake im aware of on the island that ou wouldnt want to eat anything out of is Makay lake by Mount Washington, there was an old copper mine causing high concentrations of heavy meatals in the lake. the min has since been capped but the metals will linger for a while.