By Chelsea Harvey / 
[dropcap]T[/dropcap]he state of the world’s fish stocks may be in worse shape than official reports indicate, according to new data — a possibility with worrying consequences for both international food security and marine ecosystems.
A study published Tuesday in the journal Nature Communications suggests that the national data many countries have submitted to the UN’s Food and Agriculture Organization (FAO) has not always accurately reflected the amount of fish actually caught over the past six decades. And the paper indicates that global fishing practices may have been even less sustainable over the past few decades than scientists previously thought.
The FAO’s official data report that global marine fisheries catches peaked in 1996 at 86 million metric tons and have since slightly declined. But a collaborative effort from more than 50 institutions around the world has produced data that tell a different story altogether. The new data suggest that global catches actually peaked at 130 metric tons in 1996 and have declined sharply — on average, by about 1.2 million metric tons every year — ever since.
The effort was led by researchers Daniel Pauly and Dirk Zeller of the University of British Columbia’s Sea Around Us project. The two were interested investigating the extent to which data submitted to the FAO was misrepresented or underreported.
Scientists had previously noticed, for instance, that when nations recorded “no data” for a given region or fishing sector, that value would be translated into a zero in FAO records — not always an accurate reflection of the actual catches that were made.
Additionally, recreational fishing, discarded bycatch (that is, fish that are caught and then thrown away for various reasons) and illegal fishing have often gone unreported by various nations, said Pauly during a Monday teleconference. “The result of this is that the catch is underestimated,” he said.
So the researchers teamed up with partners all over the world to help them examine the official FAO data, identify areas where data might be missing or misrepresented and consult both existing literature and local experts and agencies to compile more accurate data. This is a method known as “catch reconstruction,” and the researchers used it to examine all catches between 1950 and 2010.
