With these two reserves now linked by a marine reserve, animals that move between shore, sea and river habitats get special protection. Shags, terns, gulls and p enguins roost and breed on land but rely on the sea for food. Native freshwater fish, such as whitebait, lay their eggs in estuarine waters and the young fish are swept out to sea before returning to swim up streams where they mature. The underwater scenery within the marine reserve is generally regarded as some of the finest in the greater Wellington region and one of the best ways to get close to the fishlife is to get into the water. Those with a mask and snorkel could explore the rocks close to the shore of Kapiti Island.
Scuba diving is the most rewarding on the western side and north end of the Island.
There are some remarkable natural features, such as the rock archway on the western side of the island known as the Hole in the Wall. It is also unusual to find the three common marine habitats of the Marlborough Sounds and Wellington region in such a confined area. The boulder bottom, sheltered reef, and sand bottom habitats are home to a rich variety of marine life. Orange and yellow sponges, some very rare, colour the reefs and luxuriant seaweed beds feed kina and paua. Starfish, corals, anemones, octopus and reef fish such as butterfish, blue cod and red mullet are also residents of these waters.