## 3 Results
### Epibenthic Communities
\(p\)-values of the Student’s \(t\)-test to test for differences between areas are presented: * \(p<0.05\); ** \(p<0.01\); *** \(p<0.001\). In the southern part of the Menorca Channel, species that most contribute to similarity in Medium effort history area were the echinoderms _Ophioconis forbesi_ and _Spatangus purpureus,_ the crustaceans _P. prideaux_ and _A. laevis_, and the ascidian _A. nordmanii_; while these same species, except _S. purpureus_, jointly with the crustacean _Pagurus forbesii_ and the gastropod mollusk _Gibbula fanulum_, were the important species contributing to similarity in High effort area (Table 3). Species such as _S. purpureus, P. prideaux, E. sepositus, Dardanus arrosor, I. dorsettensis, Inuchus thoracicus,_ and _A. mentula_ showed higher abundances in Medium effort history area compared to High effort area. The sponge _Suberites domuncula_ and the ascidian _P. mamillaris_ just contribute to similarity in Medium effort history area. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Species/Taxa**} & \multicolumn{2}{c}{**Non-Impacted**} & \multirow{2}{*}{**Species/Taxa**} & \multicolumn{2}{c}{**Low Effort History**} \\ \cline{2-3}  & **A** & **\%C** & & **A** & **\%C** \\ \hline _Inachus dorsettensis_ & 113.1 & 12.3 & _Pagurus prideaux_ & 267.0 & 35.4 \\ _Buenia massutili_ & 99.2 & 11.2 & _Buenia massutili_ & 118.3 & 12.8 \\ _Pagurus prideaux_ & 74.9 & 7.4 & _Inuchus dorsettensis_ & 67.3 & 10.7 \\ _Ascidia mentula_ & 64.7 & 6.7 & _Anapagurus laevis_ & 39.3 & 3.9 \\ _Anapagurus laevis_ & 73.2 & 5.3 & _Ophiura ophiura_ & 27.0 & 3.7 \\ _Liocarcinus_ spp. & 45.8 & 4.2 & _Pagurus forbesii_ & 19.4 & 2.8 \\ _Aplidium nordmanni_ & 57.1 & 4.2 & _Ascidia mentula_ & 14.9 & 2.3 \\ _Ophiura albida_ & 48.8 & 4.0 & _Aplidium nordmanni_ & 25.6 & 2.0 \\ _Ciona_ spp. & 28.0 & 2.6 & _Dardanus arrosor_ & 16.3 & 1.9 \\ _Piliumus spinifier_ & 19.0 & 2.2 & _Spatangus purpureus_ & 84.5 & 1.9 \\ _Spatangus purpureus_ & 46.5 & 2.2 & _Molyba appendiculata_ & 21.9 & 1.9 \\ _Dardanus arrosor_ & 18.1 & 2.0 & _Enryomome aspera_ & 15.1 & 1.9 \\ _Pagurus forbesii_ & 18.8 & 2.0 & _Calyptraea chinensis_ & 16.3 & 1.8 \\ _Pallioulum_ spp. & 18.3 & 1.9 & _Fusimus pulchellus_ & 13.9 & 1.6 \\ _Mimachlamys varia_ & 26.0 & 1.7 & _Turritella turbona_ & 10.2 & 1.4 \\ _Mycale (Aegogropila) contarenmi_ & 16.2 & 1.7 & _Piliumus spinifier_ & 10.5 & 1.2 \\ _Turritella turbona_ & 20.9 & 1.3 & _Cystodytes dellechiajei_ & 12.0 & 1.1 \\ _Macropudi lianresi_ & 14.4 & 1.2 & _Ophiura albida_ & 8.7 & 1.1 \\ _Ehulia tuberosa_ & 12.8 & 1.1 & _Ehilinaster expositus_ & 5.7 & 0.8 \\ _Ehiume aspera_ & 18.0 & 1.1 & & \\ _Parthenopoides massena_ & 20.1 & 1.1 & & \\ _Inachus thoracicus_ & 10.4 & 1.0 & & \\ _Moglula appendiculata_ & 10.1 & 1.0 & & \\ _Ophiura ophiura_ & 19.5 & 1.0 & & \\ _Pisa armata_ & 9.0 & 1.0 & & \\ _Polycarpa mamillaris_ & 10.9 & 0.9 & & \\ _Calcarea sp._ & 15.6 & 0.8 & & \\ _Macropudi rostrata_ & 7.7 & 0.8 & & \\ _Laecidarium oblongum_ & 8.1 & 0.8 & & \\ _Cystodytes dellechiajei_ & 11.7 & 0.8 & & \\ _Arroglossus thori_ & 6.8 & 0.8 & & \\ _Vanneaugobius dollfusi_ & 18.2 & 0.7 & & \\ _Calyptraea chinensis_ & 9.2 & 0.7 & & \\ _Diazona violacea_ & 6.5 & 0.7 & & \\ _Clausinella fascita_ & 6.7 & 0.7 & & \\ _Siphonachulina sp._ & 10.7 & 0.7 & & \\ _Echitaster expositus_ & 9.8 & 0.6 & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Results of SIMPER analysis, estimated from standardized abundance data in beam travl samples in Non-impacted and Low effort history areas, showing mean abundance (A; individuals/1000 m\({}^{2}\)) and percentage contribution (%C) of each species contributing up to 90% of within-group similarity.