Bottom trawling is a diversified fishing method which uses numerous types of gear designs, sizes, rigging and operational methods. Therefore, impact on the bottom habitat will differ among the various bottom trawl fisheries and also to a large extent depend on the bottom conditions in the area fished. This document describes the basic principles that can be used to reduce the impact of trawling, some of which are already developed as practical solutions and implemented in commercial fisheries. Overall, however, there are presently few examples of low bottom-impact trawl gears in use in commercial fisheries. These basic mitigation measures aim at reducing pressure on the bottom of various trawl components and minimising the impacted area while trawling.