A body overseeing the fishing quota owned by Maori questions how practical it will be to re-flag foreign charter fishing vessels that are only in New Zealand waters for short periods.
A proposed law-change announced in May by the Government means about 26 foreign deep sea vessels will be required to be under New Zealand control from 2016.
But Maori Fisheries Trust Te Ohu Kaimoana says re-flagging could reduce the value of the settlement quota by up to $120 million.
Chief executive of Te Ohu Kaimoana Peter Douglas also questions whether seasonal foreign charter fishing companies will be interested in continuing to fish here after the law change.
For example, he says foreign vessel owners may not be interested in re-flagging their ships for a six week squid fishing season.