Online first articles

The red swamp crayfish is an invasive species that poses significant ecological and economic threats to freshwater ecosystems. In 2014 and 2015, a culling campaign was carried out in a lake in the northern Iberian Peninsula, where more than 165 000 individuals (4029 kg) were captured. Without losing sight of the primary objective of the work (culling), we were authorised to conduct some controlled tests to evaluate the efficiency of traps depending on their location, baiting methods, and the type and amount of bait used. We observed that traps located near reed and rush shorelines were significantly more effective (with captures ranging from 20%-354%) than those located farther from the shore. The use of lake fish as bait resulted in a 39% increase in captures compared with the use of beef heart. Using three portions of bait per trap resulted in a 59% increase in captures compared with using a single portion of bait. Furthermore, we found that when bait was placed in permeable containers that were out of reach of the crayfish's mandibles, the attractiveness of the bait was not reduced, and the number of captures was increased. Improving methods for capturing invasive exotic species, such as red swamp crayfish, is essential for optimising culling efforts and controlling these species.