Located 35 kilometres north of Picton in the outer reaches of Tory Channel, Long Island was the South Island's first marine reserve and probably has one of the longest histories of fortification in New Zealand. In 1770 Captain Cook landed on it and named it even though the island was already known as Hamote to local Maori. At this time there was a small fortified pa in one part which showed signs of having resisted heavy attacks. Even 75 years later Captain Wakefield commented on it being crowned with heavy Maori fortifications. However, between this time and European colonisation Maori occupation mysteriously ended leaving very little trace, even to the point that today the actual pa site is unknown.
The next set of fortifications were built by the New Zealand government during World War 2 in order to protect the area from a possible Japanese invasion. These included a barracks and wharves built at the northern end and an Anti Submarine Fixed Defence Station on the ridge attached to a cable loop underneath Tory Channel across to Blumine Island. These installations were never completed and are now overgrown with forest.
Such a military past belies Long Island's peaceful history. On his second voyage, Captain Cook planted possibly the South Island's first European vegetable garden on one of the island's beaches. Years later, under colonial occupation, most of the native forest cover was burned and up to 400 sheep were run on it. Farming had limited success though, with most of the island regenerating into fern and scrub by the early twentieth century. When a ranger visited in 1925 he was impressed with its potential and recommended that it be made a scenic reserve which was done the following year. In the intervening years all introduced animals except for the kiore (Polynesian rat) were eradicated and the endangered little spotted kiwi introduced. The lack of predators and extensive regeneration also encouraged breeding populations of other birds including South Island robin and fluttering shearwater.
In 1991 a group of dive clubs concerned at the rapidly decreasing numbers of fish in the Sounds recommended that the area surrounding Long and Kokomohua Islands be made a marine reserve. After considerable discussion, this was agreed on and the area 500 metres out to sea surrounding the islands is now fully protected from fishing or any other form of exploitation. The result of this decision has been a remarkable recovery in marine life to the point where fish from the reserve are now restocking other areas outside of it.