If you are intending on leaving the Cook Islands with local food or animal matter such as shells it is best that you visit the National Environment Service (NES) in Avarua to check whether you need a CITES Permit to ensure your food or souvenirs will not be confiscated at your next destination.
The Convention of International Trade in Endangered Species of Wild Fauna and Flora (CITES) is an international agreement between the member countries in place to prevent the exploitation and trade of endangered species. Although the Cook Islands is not a member, CITES permits are required to import these items into other countries such as New Zealand, Australia and the USA, therefore NES needs to ensure that your items are legally allowed to enter these countries.
If you intend to travel with locally derived food items it is best to check with authorities such as the National Environment Service, Ministry of Agriculture or Quarantine at the airport if there are any official permits required. For any food items pertaining to sea creatures, you must obtain a CITES permit from the NES.
However, as of May 2020 Paua (Tridacna Maxima) the taking of Paua out of the country is PROHIBITED and NES will no longer be issuing permits for this. The current ban only applies to those who are travelling overseas and wish to take Paua for family and friends.