Ecological indicators display reduced variation in North American catch share fisheries.

A growing push to implement catch share fishery programs is based partly on the recognition that they may provide stronger incentives for ecological stewardship than conventional fisheries management. Using data on population status, quota compliance, discard rates, use of habitat-damaging gear, and landings for 15 catch share programs in North America, I tested the hypothesis that catch share systems lead to improved ecological stewardship and status of exploited populations. Impacts of catch share programs were measured through comparisons of fisheries with catch shares to fisheries without catch shares or by comparing fisheries before and after catch shares were implemented. The average levels of most indicators were unaffected by catch share implementation: only discard rate, which declined significantly in catch share fisheries, showed a significant response. However, catch share fisheries were distinguished by markedly reduced interannual variability in all indicators, being statistically significant for exploitation rate, landings, discard rate, and the ratio of catch to catch quotas. These impacts of catch shares were common between nations and ocean basins and were independent of the number of years that catch share programs had been in place. These findings suggest that for the indicators examined, the primary effect of catch shares was greater consistency over time. This enhanced consistency could be beneficial to fishery systems and might also be an indication of more effective management.