Robberg was established as a marine protected area (MPA) in 1998. The area features rocky coastline and boulders, with two sandy beaches. The coastline is approximately 9.5km long, with 1km of sandy shore and 8.5km of rocky shore.

Robberg MPA has offshore reefs, which provide an important habitat for commercially fished sparids (sea bream) from the genus Chrysoblephus, and endemic sparids such as red steenbras and black musselcracker.

The MPA also has offshore soft sediment areas that are close to the shore, between the offshore reefs. Although these areas are low in species diversity, they are important areas for East Coast sole, silver kob and hake.

Robberg is a breeding area for the rare African black oystercatcher. Many other seabirds are known to frequent the area, including a white-breasted cormorant breeding colony. Globally threatened sea turtles, listed with the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), have been observed in the area, including the loggerhead, green and hawksbill turtles that are seen annually, and leatherback turtles, which are rare visitors.

In addition to the Cape fur seal colony that lives within the marine protected area, many species of marine mammals have been sighted (and sometimes stranded) in the Robberg MPA, including whales, dolphins and seals.