Appropriation of net aquatic primary production
Data in the preceding section indicate that feed requirements for some types of aquaculture systems place a strain on wild ®sh stocks. But what is the aggregate impact of fish farming on ocean fisheries and marine resources? Tracing the ¯ow of net aquatic primary production that moves through aquaculture (Fig. 1) provides a framework for assessing whether farmed fish production adds to global fish supplies on a net basis.