James Orr from Friends of the Earth said the figures revealed “an epidemic in relation to how we’re treating our rivers, lakes and sea loughs”.
He said fixed penalty notices – which are already used for things such as dog fouling or illegal parking – had pros and cons.
“We can’t have these cases dragged through the courts for years and years and then a pathetic fine introduced at the end.
“On the one hand we would be quite encouraged that we could simplify these processes.
“On the other hand, we need the penalty to reflect the seriousness of the crime.
“This is not like parking on a double yellow line, this is much more serious.”
Under the current rules, the maximum fine that can be handed down is £20,000.
Mr Orr called for this limit to be scrapped and said there should be an independent Environmental Protection Agency.
The Daera consultation on whether to introduce fixed penalty notices is also asking people whether or not the maximum fines should be increased to £50,000 in magistrates’ courts and whether the limit should be removed entirely in Crown courts.