Is the collapse of shark populations in the Northwest Atlantic Ocean and Gulf of Mexico real?

Increasing fishing pressure on sharks stocks over recent decades has resulted in declines of many populations and led to increasing concerns for their conservation. The extent of these declines, however, has been highly variable—the result of the level of fishing, ocean conditions, and the life history of individual species. Two recent articles have described the collapse and possible extirpation of shark populations in the northwest Atlantic Ocean and Gulf of Mexico. Herein, we examine the results of these two papers commenting on the data sets used, comparing them to other available data sets, and critically evaluating the analyses and conclusions. We argue that these conclusions have been overstated because: (1) the analyses were based on a limited number of data sets, (2) the data sets themselves are inadequate to describe the status of all shark populations in the northwest Atlantic Ocean and Gulf of Mexico reported in these studies, (3) available data sets that could produce different conclusions were not utilized, (4) some factors were not taken into account that could have biased the results, (5) there were no alternate hypotheses presented evaluating other causes of the perceived decline, and (6) the authors did not consider any current stock assessments, which in several cases report the status of sharks to be considerably healthier than asserted.