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As part of a long-term study to examine the ecological effects of beam-trawling, we investigated the immediate impact of fishing on the megafaunal component of a benthic community and the extent to which it had recovered 6 months later. A quantitative dredge was used to collect megafaunal samples following a replicated, paired control and treatment design to maximize the chances of detecting any effects due to trawling. There were two different habitats with distinct communities in the experimental area, one with stable sediments and a rich fauna, the other with mobile sediment and a relatively impoverished fauna. Immediately after fishing the composition of the community in the stable sediments was significantly altered. While the abundance of some species decreased (e.g. sea mice Aphrodita aculeata), others apparently increased (e.g. hermit crabs Pagurus bernhardus). Variation between samples from the fished areas was higher than those from the control areas. This suggests that the effects of trawling were not uniform, even though the treatment area was entirely swept at least once. The effects of fishing were not detectable in the mobile sediments. Six months later, seasonal changes had occurred in both communities and the effects of the trawling disturbance were no longer evident.British Crown copyright 1998

Many tropical terrestrial planarians (Platyhelminthes, Geoplanidae) have been introduced around the globe. One of these species is known to cause significant decline in earthworm populations, resulting in a reduction of ecological functions that earthworms provide. Flatworms, additionally, are a potential risk to other species that have the same dietary needs. Hence, the planarian invasion might cause significant economic losses in agriculture and damage to the ecosystem. In the Iberian Peninsula only Bipalium kewense Moseley, 1878 had been cited till 2007. From that year on, four more species have been cited, and several reports of the presence of these animals in particular gardens have been received. In the present study we have: (1) analyzed the animals sent by non-specialists and also the presence of terrestrial planarians in plant nurseries and garden centers; (2) identified their species through morphological and phylogenetic molecular analyses, including representatives of their areas of origin; (3) revised their dietary sources and (4) used Species Distribution Modeling (SDM) for one species to evaluate the risk of its introduction to natural areas. The results have shown the presence of at least ten species of alien terrestrial planarians, from all its phylogenetic range. International plant trade is the source of these animals, and many garden centers are acting as reservoirs. Also, landscape restoration to reintroduce autochthonous plants has facilitated their introduction close to natural forests and agricultural fields. In conclusion, there is a need to take measures on plant trade and to have special care in the treatment of restored habitats.

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