Assessing the Behavioral Responses of Dungeness Crab Exposed to Laboratory-Induced Electromagnetic Fields

The developing marine and hydrokinetic (MHK) renewable energy industry is faced with a broad range of permitting issues, including environmental concerns related to impacts on sensitive life stages of commercially and recreationally important aquatic organisms. One such concern in coastal and estuarine areas is the potential effect of electromagnetic fields (EMF) produced by underwater power transmission cables.  In many cases little is known about the behavioral response of organisms to EMF, or the cumulative impacts of multiple devices that might elicit a behavioral or physiological response.  In this presentation we will focus on the results of a series of recent and on-going laboratory trials measuring the behavioral responses of adult male Dungeness crab to a simulated EMF source (Helmholtz coil).  In initial trials a change in the antennular flicking rate of the crab before and after an EMF increase has been used as a measure of detection.  The crabs ability to detect a food extract after a longer-term exposure to EMF has also been examined using the antennular flicking rate.  On-going and future trials are examining the avoidance/attraction behaviors to EMF by Dungeness crab under varied conditions of refuge and prey availability.  Results from these experiments, as well as planned studies for other species of invertebrates will be discussed in the context of permitting challenges facing the marine and hydrokinetic renewables industry.