Just offshore from New Plymouth lies the remains of an ancient volcano much older than Mt Taranaki.  This group of low sea stacks and seven islands provide a unique semi-sheltered environment along an otherwise exposed coastline.​

The Sugar Loaf Islands Marine Protected Area (SLIMPA) was established in 1986 to provide protection for the marine environment from fishing, oil exploration and mining. It lies between the Port Taranaki Breakwater and the Herekawea stream and overlaps on the Tapuae Marine Reserve.

Within SLIMPA's boundaries no commercial fishing is allowed except trolling for Kingfish and Kahawai. Individual fishers are restricted to one rod with a maximum of three hooks and set netting and long lining is banned.

Within the Tapuae Marine Reserve all marine life and natural features are protected.  This means no fishing, netting or spearfishing, and no disturbance of crayfish, kina or any marine inhabitant or objects.