Part of the response from MPI is that it is only recently they have put detection methods in place. Last 10 months after the work that Legasea had campaigned for.
It is claimed that MPI had evidence of widespread dumping but did not act on it (the photos that the report says were covered up).
Also we as anglers know have technology to record this, but as a young angler at Kawhia in the 1970s seeing large numbers of gurnard floating down the harbour obviously dumped in the harbour.
The truth is probably between the two sets of claims either way it is unacceptable.