Off the booksOne of the big problems with fighting overfishing is that the quality of the data is often bad. A lot of fishing takes place off the books, and so can't be invoked by scientists and policymakers who want to bring fishing back on a more sustainable course.
But sometimes, there's a clever way to get around the lack of data. Dalal Al-Abdulrazzak, a Ph.D. student with the University of British Columbia Fisheries Centre, grew up in Kuweit where she often say fishing weirs (giant fish traps, as seen on the images above and below) along the coast of the Persian Gulf. She decided to compare the official numbers reported to the U.N. with what she saw on satellite imagery from Google Earth and realized that the amount of fish caught by these weirs may be six times higher than the official number.
Al-Abdulrazzak said it took her about four months of patient sifting through satellite images and careful counting to estimate a total of 1,900 weirs in the Persian Gulf. She then asked fisheries scientists in the Middle East what average annual fish catches were per weir.
Based on that information, she estimated that weirs in Kuwait, Saudi Arabia, Qatar, the United Arab Emirates, Iran, and Bahrain scoop up about 31,000 tonnes of fish a year, plus or minus 10,000. That is about six times higher than the 5,260 reported to the United Nations Food and Agriculture Organization in 2005. (source)
Some countries in the region - Saudi Arabia, Qatar and Iran, for example - didn't even report any weir fishing catches at all... Shows how in theory, theory and practice are the same. But in practice, they're quite different...