Using public encounter data to direct recovery efforts for the endangered smalltooth sawfish Pristis pectinata

Conservation planning for difficult-to-survey endangered species can be challenging because information on distribution, abundance, and habitat associations is hard to gather. We used data provided by the public for an easily identified rare marine species, the endangered smalltooth sawfish Pristis pectinata, to provide information to direct recovery efforts in US waters. Data from public encounters from 1998 to 2008 occurring between Texas and Georgia were analyzed. Most records (99.7%) were from Florida waters. Although all size classes were reported, the majority were sawfish ≤200 cm estimated total length. There was an inverse relationship between sawfish size and extent of northern distribution, with ≤200 cm animals having a wider latitudinal distribution and occurring farthest north, and >200 cm animals reported mostly in southern Florida. Most encounters occurred in estuarine and nearshore habitats, and their locations were not randomly distributed, having positive association with inshore mangrove and seagrass habitats. While sawfish were reported in depths up to 73 m, there was a significant relationship between size and depth, with smaller animals occurring in shallower waters. Although historically common from Texas to North Carolina, this study shows that the core range of smalltooth sawfish is now the area in Florida from the Caloosahatchee River south through the Ten Thousand Islands and Everglades National Park to Florida Bay. These results provide resource managers with information to direct recovery efforts, including the current range, areas where recovery may be expected to occur, and the habitat needs of various size classes