BOEM Environmental Studies: EMFs and Marine Life
Naturally occurring EMF are present everywhere in the oceans. Undersea cables used for power transfer are known sources of EMF, but telecommunication cables and undersea communication cables also generate alternating current (AC) and direct current (DC) EMF.
PDF Available here: https://www.boem.gov/sites/default/files/documents/renewable-energy/state-activities/Electromagnetic-Fields-Marine-Life.pdf