The use of sea urchins to control fouling during suspended culture of bivalves

Abstract

We evaluated the efficiency of the sea urchins Lytechinus variegatus and Echinometra lucunter as a biocontrol of fouling on nets and on bivalve shell of the pearl oyster Pinctada imbricata during culture, using suspended pearl nets from long lines, located in Turpialito, Golfo de Cariaco, Venezuela, for 3 months. We established four treatments: nets with (1) two E. lucunter, (2) two L. variegatus, (3) one L. variegatus and one E. lucunter, and (4) without sea urchins. At end of the experiment, all sea urchins were alive and the pearl nets with the sea urchins had a significantly less dry mass of net fouling than nets without sea urchins. Although E. lucunter reduced the fouling on the nets by 45%, it did not reduced fouling on shells of the oysters. L. variegatus reduced fouling on nets by 74% and fouling on the shells by 71%. This work is the first report demonstrating the usefulness of sea urchins in controlling fouling in bivalve culture. We recommend the use of sea urchins to reduce net and shell fouling during the culture of tropical bivalves.