The effects of electrified submarine cables on movements of two commercially important crustacean species

Submarine energy infrastructure is expanding rapidly as offshore energy extraction and transport intensifies. Power transmission through submarine cables creates anomalies in the Earth's geomagnetic field, potentially affecting marine species that use natural electromagnetic fields (EMF) to navigate and forage. Most research on EMF effects on marine animals use laboratory or mesocosm experiments that constrain subject animal movements. The artificial nature of these studies limits their extension to real-world environments, creating uncertainty in predicting impacts of important infrastructure projects. We use hyperbolic positioning acoustic telemetry to assess the impacts of the Maritime Link submarine transmission line on the movements of commercially important Snow Crab and American Lobster. Our results show that crossing rates were not affected by the presence and operation of the submarine cables, nor was the movement velocity different in the cables' proximity. In contrast, we found effects of temperature and diel period on movement speeds of both species. The methods used here could be useful to future research on EMF effects in other species and in areas with more extensive underwater infrastructure.