This mixed sea bass and sea bream cage farm in Izmir Bay, eastern Aegean coast of Turkey, operates 18 cages producing a combined 3,000 tonnes annually. Water temperatures range from 14 degrees C in February to 28 degrees C in August, driving year-round biofouling with no winter respite. The fouling community is dominated by calcareous organisms — principally the tubeworm Hydroides elegans and the barnacle Amphibalanus amphitrite — which together accounted for 75 percent of fouling biomass in baseline surveys. This hard-fouler dominance makes cleaning exceptionally labour-intensive and damaging to net fibres, with the farm replacing its full net inventory every 12 to 14 months at an annual cost of approximately 220,000 euros.
A 12-month copper-alloy net trial was conducted on 4 cages, with 14 standard nylon-net cages serving as controls on the existing biweekly cleaning schedule. The copper-alloy panels remained 95 percent clean after 12 months of deployment, while nylon control nets were fully encrusted within 6 weeks of each cleaning. Fish performance data showed that sea bass and sea bream in copper-net cages consumed 12 percent less feed for equivalent growth — a result consistent with sustained water exchange and oxygen supply through the unfouled mesh. Extrapolating the feed savings and eliminated cleaning costs, the farm calculated a payback period of 22 months on the copper net investment, well within the projected 5-year panel lifespan.
The warm-water fouling species found at this site are documented in the organisms database, and the farm location is plotted on the aquaculture farm map with year-round fouling intensity data. For a detailed comparison of copper alloy nets with other warm-water anti-fouling options, use the solutions comparison tool. The biofouling cost calculator can model payback periods for copper net investments at different production scales and fouling intensities.
Outcomes
Warm water temperatures drove year-round fouling with no winter respite. Calcareous tubeworms (Hydroides) and barnacles dominated — hard foulers accounted for 75% of biomass. Copper-alloy net panels remained 95% clean after 12 months while nylon controls were fully encrusted. Fish in copper-net cages consumed 12% less feed for the same growth.