The recent expansion of the invasive blue crab Callinectes sapidus along Mediterranean coasts has posed serious ecological and economic challenges, particularly for small-scale fisheries. One of the major issues reported by local fishing communities is the significant economic loss resulting from the destruction of fishing gear and the target catch eaten by the crabs. To mitigate these impacts, it is essential to understand which materials used in fishing gear construction are most resistant to the mechanical damage caused by this invasive species.

The objective of this study was to assess the breaking strength of six different types of nets commonly employed by local fisheries in the fabrication of passive fishing gear (gillnets, trammel nets and fyke nets). Experiments were carried out in mesocosm using panels of different nets positioned to create a physical barrier between the offered food items and the crabs. For each experiment (R=5) a single adult male blue crab was introduced into each tank and its behavior was video recorded for 24 hours.

At the end of the experiments, all net panels were examined for signs of damage and the time taken for the crab to break the material was recorded. The results revealed differences in material resistance showing that not all the tested materials are susceptible to crab-induced breakage. More in details, of the two fyke nets tested only one suffered damage, while polyamide monofilament resulted the most susceptible to tearing or cutting by the crabs. Conversely, the thicker polyamide multifilament showed a significantly higher structural integrity, resisting tearing even after repeated attempts by the crab to access the bait.

These preliminary results suggest that some materials may be better suited for use in areas heavily infested with blue crabs, potentially reducing economic losses associated with gear damage and lost catches.