Proposed changes to crayfishing in Canterbury and Marlborough should make it a lot harder for poachers to sell their catch.

The MPI's seeking public feedback on two changes to quota management in the CRA5 area off the north-east coast of the South Island.

It estimates up to $2 million worth of the species are being illegally sold each year from that site.

Inshore Fisheries Manager Steve Halley said black market sales should drop with new recreational catch limits and new labelling methods.

"They will better enable us to identify a fish taken by recreational fishers, if people tried to sell that fish through commercial premises."

Meanwhile Ngai Tahu is applauding the Government's decision to protect endangered eel stocks in Lake Ellesmere, known as longfin tuna.

The vulnerable species is considered taonga for the iwi.

The Government's decided to separate management of longfin and shortfin eel stocks to reduce the take of longfin.

ECAN and Ngai Tahu made a joint submission last year recommending separate rules for the species.

Iwi leader Mark Solomon said there's a responsibility to protect the lake, its ecosystem, and the taonga species, and this is a step in the right direction.