Still used in Martinique, seines are nets with very small mesh generally free of knots to avoid damaging the fish. They make it possible to encircle previously detected shoals of fish and to capture them alive without harming them. The upper part of a seine is mounted on a floating line, while the lower part is attached to a weighted braid. Setting the seine in the water is called filage. A slide allows the lower part of the net to be pursed at the end of the encirclement to prevent the escape of the fish through the bottom.