Pietro, forms a more or less protected basin, upon the shores of which are several small harbours (the most important being Carloforte), which are centres of the export of minerals and of the tunny fishery.
The tunny fishery is considerable; it is centred principally in the south-west.
Neither the tunny nor the coral fishery is carried on by the Sardinians themselves, who are not sailors by nature; the former is in the hands of Genoese and the latter of Neapolitans.
Parts of the island are fertile, and the cultivation of vines, and the tunny and sardine fishery, also give employment to a part of the population.
Of sea-fish there are many varieties, the tunny, the sardine and the anchovy being commercially the most important.