A designed artificial reef is among the most productive marine fish habitats: new metrics to address ‘production versus attraction’

has local production. The local fish production at this artificial reef was 384 g m−2 year−1, which is within the 105– 887 g m−2 year−1 range reported by Claisse et al., although our study included visitor species not included by Claisse et al. We estimate that the fish production new to the ecosystem may only be 4–5 % of the local production, due to the large abundance of visitor species on this reef. The annual flux of biomass across this reef was very large, ~380 times greater than the standing stock biomass, meaning that this reef is vulnerable to overexploitation from fishing. Our results show that like oil platforms, designed artificial reefs can be very productive marine habitats, but may not greatly increase the net fish production in a system. The method detailed here will allow similar studies to be done relatively simply at other marine habitats, including fish aggregation devices.