Commercial fishing operations get most of the blame for overfishing, but they're not the only player. Recreational anglers can also have a big impact on fish populations  by dint of their numbers: An estimated 11 million anglers took some 73 million saltwater fishing trips in the United States in 2010. How many fish they catch, however, has been somewhat uncertain.
Today the National Oceanic and Atmospheric Administration (NOAA) announced that it has finished an "ambitious overhaul" of its methods for estimating the impact of recreational fishing . A more accurate count will allow the managers to improve their regulation of fisheries.
NOAA began its surveys of sport fishing in 1981, combining dockside interviews with telephone surveys. These data have been included in assessments of the health of regional fish stocks. When those assessments led to a decision to restrict fishing, however, the fishing community would criticize the data as unreliable. "It would be a lightning rod," says fisheries biologist Gordon Colvin, who manages NOAA's Marine Recreational Information Program . Fisheries managers had their own bone to pick with the survey data, complaining that they aren't adequate for making decisions at the local scale.
In 2005, NOAA asked the National Research Council of the U.S. National Academies for advice. Its 2006 report identified a number of untested assumptions and potential sources of error . NOAA has adopted the suggestions, such as to survey docks at various times and seasons rather than just at their busiest.
The previous method apparently did not lead to any systematic biases, however. When the agency applied the new methods for estimating catch to data dating back to 2004, it found that some estimates had been too high and others too low. Roughly half were within 5% of the original estimate, and only one in five differed by more than 15%.
NOAA is also working to improve its data collection. In 2010, it started the National Saltwater Angler Registry , which has made its survey more efficient by providing the agency with a way to contact anglers. And next month the agency wraps up a pilot study on charter boats in Florida and North Carolina of electronic logbooks, which provide real-time reporting of catches. Both these approaches should mean more data and increased precision, Colvin adds.