Llyn Peninsula hobby lobster fishermen 'damaging beds'
Fishermen in Gwynedd have raised concerns that people who take lobsters without a permit are damaging the beds.
Chris Jones, from Pwllheli, said "hobby potters" take undersized creatures, which will affect future stock.
He added people without professional licences, which cost £12,000, were putting their pots on top of his and taking his lobsters.
The Llyn Pot Fishermen's Association said it was a problem in other areas along the Welsh coast too.
Mr Jones told BBC Radio Cymru's Post Cyntaf programme he purposely put undersized lobsters in a pot and within a few days they had been taken.
There is a fisheries officer responsible for the coastline but Mr Jones said despite doing an "excellent job" she was not able to cover the whole area.
A Welsh Government spokesman said: "Anyone wishing to fish recreationally using pots in north Wales must apply for a permit, which has a number of conditions attached.
"Our fisheries unit monitors this activity closely and works with the industry should any concerns be raised."