Trapping Callinectes sapidus (Atlantic Blue Crab) in the Mediterranean: What Can Be Learned from Carcinus maenas (European Green Crab) Pest Management.

Invasive marine crustaceans present ecological and socio-economic challenges, particularly where high fecundity, behavioural plasticity, and environmental tolerance limit the effectiveness of conventional control measures. The Atlantic blue crab, Callinectes sapidus, has expanded across the Mediterranean, where it exerts strong predatory pressure on native species and aquaculture resources, yet management efforts rely largely on traditional baited trapping. Drawing on extensive evidence from the global management of the European green crab, Carcinus maenas, we evaluate why conventional trapping has failed to achieve sustained population suppression in invasive brachyuran crabs. We synthesise lessons from green crab control to identify common biological and operational constraints, including rapid compensatory population responses, bycatch, and limited behavioural selectivity. We then examine the potential of semiochemical-based strategies-incorporating olfactory cues-within an integrated pest management (IPM) framework. Semiochemical-enhanced approaches offer the capacity to directly exploit species-specific sensory ecology, improve trap selectivity, and reduce non-target impacts, addressing fundamental limitations of existing methods. We argue that prioritising such IPM, rather than further optimisation of traditional trapping alone, represents the most realistic pathway for long-term mitigation of C. sapidus in the Mediterranean. While eradication remains improbable, strategically deployed semiochemical-based control could substantially enhance suppression efficiency and inform broader invasive species management.