Agriculture is widespread on Alonnisos, predominantly mixed farming and vineyards. The main products are
almonds,
grapes,
figs and
olives.
Pine trees are abundant on the island. While fishing is a popular profession on the island, tourism is now the main industry. Housing traditionally consists of closely constructed houses with stone walls, which, until 1965, were centered on the capital. A small fortress protected against enemies and pirates. The island and the village were heavily damaged in an
earthquake on 9 March 1965. Many inhabitants returned not to the village of Alonnisos, but to Patitiri. The old village has been restored in recent years, with rebuilt houses now utilised for tourism. The beaches around the island consist of pebbles. The ecosystem in the north side of the island is in good condition. The
Mediterranean monk seal (
Monachus monachus) is common around the island, and in 1992 the
Alonnisos Marine Park was created to protect these seals and other animals. In July 2021, Kostis, a monk seal that was the mascot of the island, was killed, apparently by a spearfisher. ==Communities and subdivisions==