Determining the safety range of electrical pulses for two benthic invertebrates: brown shrimp (Crangon crangon L.) and ragworm (Alitta virens S.)

A laboratory study was conducted to determine the impact of an electrical field on mortality rates and histological changes on model marine organisms. The tests were carried out to provide more information on the impact of electrotrawling om marine species. Two species of invertebrates, brown shrimp (Crangon crangon L.0) and king ragworm (Alita virens S.) were used as model species for crustaceans and polycheates, respectively. Specimens were expose to a homogeneously distributed electrical field varied by frequency (5-200 Hz), electrical field strength (150-200 Vm-1), pulse polarity, pulse shape, pulse duration (0.25-1 ms), and exposure time (1-5 s). Shrimp tended to do a tail flip in response to some electric pulses and ragworm showed a squirming response independent of the frequency. There were no increases in mortality or injuries for either species with any of the pulse parameters tests. Shrimp exposed to 200 Vm-1 showed significantly higher severity of intranuclear baculoform virus infection.