Preliminary Study on the Effects of Electromagnetic Fields on the Burial Behavior and Location of Dungeness Crab, Cancer Magister

摘要

Ocean-energy devices offer a vast potential for providing renewable power, however there are a number of environmental concerns related to the location and routine operation of these devices. A variety of designs harness the oceans currents, waves, wind, or some combination of the three to generate electricity for land-based needs. While it is known that underwater structures may attract marine communities, it is not well understood yet how the electromagnetic fields (EMF) generated by power transmission cables bringing electricity to shore will affect marine life. In this preliminary laboratory study we examined how exposure to an EMF source might affect the behavior of the Dungeness crab, Cancer magister, in a 72-hr experiment. We recorded crab location preferences and activity level in a control tank and an exposure tank that contained a non-uniform EMF generated by a Helmholtz Coil. We found that crabs in the EMF exposure tank were located more frequently in a zone of high EMF compared to other areas of the tank, and compared to the same zone in the control tank. In addition, the activity level of crabs in the zones of low EMF in the exposure tank was greater than in the same zones on the control tank receiving background EMF levels. These results suggest there may be possible behavior responses to EMF, however further replication is needed in the laboratory as well as field verification.