The effect of pulse stimulation on biota - Research in relation to ICES advice - progress report with preliminary results

In response to questions asked by ICES on the effects of pulse stimulation in commercial beam trawling on components of the marine ecosystem a number of preliminary studies were undertaken in the period between 31 May and 5 October 2007. These activities involved: 1. Measurements on the detailed stimulus applied in the pulse trawling system developed by the company Verburg-Holland Ltd., i.e. the amplitude, pulse width, rise and fall times, repetition rate and field strength along the electrodes. These measurements were done onboard of the commercial fishing vessel MFV “Lub Senior” (UK153), and in tank facilities of the manufacturer of the pulse beam trawl. 2. Simulation of this stimulus in the recirculated aquaculture system available at IMARES 3. Development of a protocol for keeping small-spotted catsharks alive and well, including dietary requirements. 4. The exposure of catsharks to a simulated pulse under laboratory conditions and observation of behaviour, including foraging, and monitoring mortality 5. Investigation of possible spinal damage of cod caught by a commercial vessel using pulse beam trawls by X-ray photography.