Afriforum is threatening Environmental Affairs Minister Edna Molewa with legal action.
This follows her decision recently to approve the rezoning of the Tsitsikamma Marine Protected Area, to allow fishing by members of local communities.
It is the oldest marine protected area in the country and home to 20 endemic species of fish.
Nine of these fish species are on the World’s Red List of Threatened Species.
Chris Boshoff, AFriforum’s coordinator for environmental affairs, says Molewa failed to answer critical questions regarding her decision.
Boshoff says Molewa did not take the contents of 700 scientific reports on marine conservation into consideration, before the decision was published in the Government Gazette on 19 December 2016.
AfriForum is urging Minister Molewa to explain in writing what her reasons were for granting permission for local communities to fish in three protected areas.
The organisation demands that scientific evidence, that motivates Molewa’s decision, be released to the public.