A floating, electric fence (1) arranged to inflict injury on a pelagic larva in sea water； the electric fence (1) is provided with a buoyancy element (5； 12, 12'； 26), a bottom element (14, 14', 14"), an anchoring device (18), at least two electrical conductors (16, 16a, b) which are positioned side by side and which are submerged at least in a portion, the at least two electrical conductors (16, 16a, b) being connected to an electric DC source arranged to provide the first of the at least two electrical conductors (16, 16a, b) with pulsating electrical current and with alternating polarity, and to provide the second one of the at least two electrical conductors (16, 16a, b) with pulsating electrical current of opposite polarity to that of the first electrical conductor (16, 16a, b). A method of damaging a pelagic larva in sea water is described as well, the method including letting the larva drift into a pulsed electric field in which the field direction is reversed between pulses.
