Local Knowledge of Distribution of European Green Crab (Carcinus maenas) in Southern Nova Scotian Coastal Waters

Local knowledge is making important contributions to environmental management. Improving understanding of local knowledge that is in the early stages of development may be useful towards management of novel species or understanding other contemporary events. In this study we interviewed Nova Scotian fishermen with experience with a recently arrived invasive species, the European green crab (Carcinus maenas), to evaluate their knowledge of its local distribution. Ten participants who had either fished green crab or experienced it as a by-catch were interviewed. Environmental, temporal and internal population factors that were frequently associated with green crab distributions were reported by participants. Environmental factors described included primarily depth, vegetation, biotic interactions and bottom type. Furthermore, interactions with temporal factors (e.g. tidal and seasonal changes) as well as internal-population factors (e.g. sex and age) were observed by a number of participants. Internal factors were described more frequently among participants with more experience and more direct associations with green crab. Local knowledge illustrates not only a nascent understanding of this species’ distribution, but realization of internal population structure and temporal variations, which may help to refine management strategies. This study illustrates the potential for local knowledge to form and develop, even around relatively recent environmental events.