Were not herrings destroyed by men and by fish, or by birds, they would soon cover the whole surface of the ocean. The violent death would be deferred, not prevented. They would perish, by their numbers, by famine, and perhaps by contagion. The number of herrings taken annually by the Swedes alone were estimated at seven hundred and twenty millions, two thirds of which were used for producing oil. The Yarmouth fishery, in a good season, produces one hundred and forty millions.
Herrings are the prey of almost every sea fish, and of almost every sea bird.
The gull and the gannet indicate to fishermen where to cast their nets. In the heat of the day the herrings are invariably partial to the deep waters, and are lost sight of by the sea fowl. The methods of catching the fish and of curing them are different in different countries. I shall confine my attention to the customs of the Isle of Man. Between four and five hundred fishing boats, of usually about sixteen tons burden each, and not decked, compose the Manks fleet.