it is estimated that between and million tonnes of fish are caught by iuu fishing annually representing of global catches across all fisheries agnew et al this represents a substantial pressure on fish stocks above what would be considered as desirable however it is claimed that the number of economically overfished stocks is even higher than the number that is biologically overfished eg pauly and zeller in new zealand the percentage of fish stocks above the overfishing threshold declined percentage points from in to in