There is widespread concern and debate about the state of global marine resources and the ecosystems supporting them, notably global fisheries, as catches now generally stagnate or decline. Many fisheries are not assessed by standard stock assessment methods including many in the world's most biodiverse areas. Though simpler methods using widely available catch data are available, these are often discounted largely because data on fishing effort that contributed to the changes in catches are mostly not considered.
We analyse spatial and temporal patterns of global fishing effort and its relationship with catch to assess the status of the world's fisheries. The study reveals that fleets now fish all of the world's oceans and have increased in power by an average of 10-fold (25-fold for Asia) since the 1950s. Significantly, for the equivalent fishing power expended, landings from global fisheries are now half what they were a half-century ago, indicating profound changes to supporting marine environments. This study provides another dimension to understand the global status of fisheries.