Stakeholder Concerns Guiding Ecological Modeling: Development of a Spatio-Temporal Model of Shell Disease in American Lobster

The expansion of epizootic shell disease (ESD) in the northeastern United States has become a threat to the American lobster (Homarus americanus) fishery. We conducted an anthropological investigation of New England lobster harvesters to quantify the perceived threat of ESD in the Gulf of Maine and Southern New England to guide the construction of an ecological model of the disease’s distribution. Using surveys and interviews, we determined that harvesters are significantly worried about the impact of ESD on the lobster fishery. Additionally, in alignment with current scientific hypotheses, most harvesters believe that physiological stress from numerous factors cause ESD outbreaks, although they would like this belief to be substantiated. To this end, a generalized additive model was developed to quantify relative importance of potential biotic and abiotic contributors to disease prevalence. Our model identified significant abiotic (i.e. depth, bottom temperature) and biotic (i.e. carapace length) variables contributing to ESD prevalence. Given these relationships, we have developed graphical representations of potential ESD spread from 1984 to 2013. Our model provides the knowledge necessary for early detection and forecasting of the environmental conditions that contribute to spread of ESD and consequently could be of value for the management of the American lobster.