It is well known that bottom trawling affects the abiotic (seafloor morphology, sediment
resuspension, water turbidity) and biotic components (biodiversity, biomass and
production) of habitats. However, comparative studies on the effect of trawling on epibenthic
communities of sedimentary bottoms are scarce. One of the objectives of LIFE IP
INTEMARES project is to assess the impact of bottom trawling on vulnerable benthic
habitats of the circalittoral bottoms of the Menorca Channel (western Mediterranean),
designated Site of Community Importance (SCI) within the Natura 2000 network. The
present study compares the benthic communities of four areas subjected to different
bottom trawl fishing intensity levels (null, intermediate and high). The assignment of
fishing effort levels was based on the fishing effort distribution in the area calculated from
Vessel Monitoring System (VMS) data. The biological samples were collected from 46
beam trawl stations sampled during a scientific survey on April 2019. In order to detect
differences related to the different levels of fishing intensity, we calculated four
“traditional” diversity indices (i.e. species richness, Margalef’s richness, Pielou’s evenness
and Shannon’s diversity), and the recently developed N90 diversity index, which has shown
to be useful in the detection of the response of demersal and benthic communities to
fishing pressure. Our results show the highest values of all the analyzed indices in the nonimpacted
area, suggesting a negative effect of bottom trawling on the benthic communities
present in Menorca Channel. However, no clear pattern was observed between different
degrees of trawling intensity and diversity values, so other factors such as environmental
conditions must be also considered to explain these results
