The high discards rates of non-commercial benthic species is one of the main problems of the Mediterranean bottom trawl fishery developed on the continental shelf. The present work analyzes data from 22 bottom trawls, carried out in parallel by two commercial trawlers between 70 and 90 m depth on maërl beds off eastern Menorca (Balearic Islands). One vessel used an experimental trawl gear (EXP) equipped with a lighter and smaller groundrope in the mouth of the net, leaving a gap without net between the main groundrope and the secondary one. The other vessel used a trawl gear traditionally used by the fleet operating in the area (TRA), without that modification. Catches, discards and commercial yields between both gears were compared. Discarded biomass of non-commercial benthic species with EXP was reduced by half when compared to TRA, particularly for rhodoliths (54%) and ascidians (51%). The reduction of discarded rhodoliths is especially relevant in the Balearic Islands where sensitive habitats, such as maërl beds, are an important part of the benthic communities. The modification of the net, at the same time, does not imply a reduction of yields of commercial captures and can easily be implemented in any bottom trawl net. It is concluded that this could be an appropriate and plausible technical measure to improve the ecological efficiency and the sustainability of the Mediterranean bottom trawl fishery.

非商业底栖物种的高丢弃率是在大陆架上发展的地中海底拖网渔业的主要问题之一。本工作分析了22个底部拖网的数据，该拖网是由两个深度在70至90 m的商用拖网在梅诺卡岛东部（巴利阿里群岛）东部的马尔尔河床上并行进行的。一艘船使用的是实验拖网渔具（EXP），其网孔中装有较轻和较小的地网，在主地网和副地网之间留有没有网的间隙。另一艘船使用拖网渔具，该拖网渔具传统上是在该区域（TRA）运营的船队使用的，而没有进行任何修改。比较了两个渔具之间的渔获量，丢弃物和商业收益。与TRA相比，EXP非商业底栖物种丢弃的生物量减少了一半，特别是对杜鹃石（54％）和海鞘（51％）。减少废弃的杜鹃石在巴利阿里群岛尤为重要，在巴利阿里群岛，敏感的栖息地（如马尔埃河床）是底栖生物群落的重要组成部分。同时，对网的修改并不意味着降低商业捕捞的产量，并且可以轻松地在任何底拖网中实施。结论是，这可能是提高地中海底拖网渔业生态效率和可持续性的一种适当而合理的技术措施。这并不意味着减少商业捕捞的产量，并且可以很容易地在任何底拖网中实施。结论是，这可能是提高地中海底拖网渔业生态效率和可持续性的一种适当而合理的技术措施。这并不意味着减少商业捕捞的产量，并且可以很容易地在任何底拖网中实施。结论是，这可能是提高地中海底拖网渔业生态效率和可持续性的一种适当而合理的技术措施。