European sea bass (Dicentrarchus labrax) and gilthead sea bream (Sparus aurata) are farmed in floating cages across the Mediterranean, primarily in Greece, Turkey, Spain, Croatia, and Egypt. The warm water conditions that suit these species also drive aggressive year-round biofouling.
The fouling community on Mediterranean fish cages is dominated by hard organisms. The striped barnacle (Amphibalanus amphitrite) and calcareous tubeworm (Hydroides elegans) are the two biggest problems — both produce cemented calcareous structures that resist all but heavy mechanical cleaning. Unlike Norwegian salmon farms where hydroids and mussels dominate, Mediterranean cage farmers deal with a fouling community that is harder to remove and damages nets more during cleaning.
Fouling impacts fish performance through the same water flow mechanism as in salmon farming, but with one difference: Mediterranean cage sites often have weaker currents than Norwegian fjord sites, so the effect of net occlusion on dissolved oxygen is more immediate. Farm data from Greek and Turkish sites shows 8-12% faster growth in cages with copper-alloy nets compared to standard nylon — a difference large enough to shift the economics of the entire production cycle.
Cleaning schedules in Mediterranean aquaculture tend to be more frequent than in the north — every one to two weeks during the warm months, which is most of the year. Net changing (removing fouled nets and replacing with clean ones) is common because the heavy calcareous fouling wears through nylon fibres faster.
Copper-alloy nets and ROV cleaning systems are becoming standard equipment at larger Mediterranean farms. The return on investment calculation favours copper nets more strongly here than in cooler waters, simply because the cleaning cost they eliminate is higher. Use the cost calculator to model the savings for your operation.