Abstract
This report summarizes the results of a top-level literature survey on the topic of the electromagnetic (EM) effects on marine biota. The primary driver for this survey was to determine the basic state of knowledge on the topic of potential biological effects that EM fields (EMF) may have on marine species, and then to apply that knowledge to identify EMF sensing requirements. In particular, specific knowledge was sought on species sensitivity to field strength to electric or magnetic fields and on the frequency range of such sensing sensitivity. It was noted as a result of the survey (Table 1) that EM sensitivities varied significantly by species. Elasmobranchs (sharks and skates) were noted to have extreme sensitivity to low frequency AC electric fields, including the area between 1/8th to 8 Hz, but no notation was made for sensitivity to magnetic fields. Telost fish, including salmonids, also have an electric field sensitivity, but one that is orders of magnitude lower (less sensitive) than sharks. Elasmobranchs provide the most stringent requirement for electric field sensing, with some species sensitive to levels as low as 1 nV/m (1 x 10-9 volts/meter). On the other hand, benthic species and some marine mammals have been observed to be affected to varying degrees by magnetic fields, but not electric fields. Magnetic sensing requirements appear to be driven by eels, which the literature reports as having sensitivities to magnetic fields on the order of a few μT (1 x 10-6 Tesla). Some benthic species have been shown to be affected by stronger magnetic fields, although there has been little research reported on the subject of certain species native to the Pacific Northwest, including the Dungeness crab. In summary, a number of species were reported to be sensitive to EM fields, and could potentially be affected by EM fields created by wave energy devices and cables. Thus, instrumentation used to assess the impact of EM fields should provide adequate resolution to allow direct measurement of known sensitivity levels. Furthermore, it would be desirable, but not required, to investigate instrumentation that is capable of measuring levels below the known levels of sensitivity to enable future research on any collected data that may have an observable impact.