Tikopians practice an intensive system of agriculture (which has been compared to permaculture), similar in principle to forest gardening and the gardens of the New Guinea Highlands. Their agricultural practices are strongly and consciously tied to the population density. For example, around 1600, the people agreed to slaughter all pigs on the island, and substitute fishing, because the pigs were taking too much food that could be eaten by people. Tikopians have developed rituals and figurative constructions related to their fishing practices.