Fishermen using small fishing boats based in English ports have said they are frustrated at increasing amounts of inspections in preparation for Brexit.
The Marine Management Organisation (MMO) is extending surveillance to "deter and detect illegal fishing by any vessels in English waters".
The extra checks are being done in port and at sea using boats and aircraft.
Fishermen based in Newlyn, Cornwall said "we feel under so much scrutiny that people have given up".
The MMO said the changes would bring vessels under 10m in line with other fishing boats around the coastline.
Fisherman Nigel Taylor said: "The MMO were rarely around but now all of sudden they are in force and it is rubbing a few people up the wrong way.
"They haven't enforced landings all this time while we have been in the European Union and when they should have been enforcing Spanish boats, French boats, Belgian boats landing in the ports. Now with the local boats they are all over them - it is crazy."
Landing obligations are designed to protect fish stocks and apply to species that are managed by quota limits.
The fishermen have always been subject to the regulations but say the regular checks are adding increased pressure.
The MMO said it had "strengthened its capabilities... to get ready for the UK becoming an independent coastal state after Brexit."
This includes "an increase in personnel, vessels and aerial patrols to deter and detect illegal fishing by any vessels in English waters and to provide reassurance to hard working fishermen," it added.
It is also introducing the recording of catches for the under-10m fleet to give a "clearer picture" of the fish being taken from the sea.