Current knowledge of turbid coastlines relies heavily on extrac ve sampling methods with less destruc ve visual techniques limited primarily by underwater visibility.  Such coastlines are present around Wales, especially dynamic loca ons targeted for marine renewable energy developments.  Baited Remote Underwater Video (BRUV) is now a commonly used non-extrac ve sampling technique which involves the use of bait to a ract mo le fauna to the fi eld of view of the camera, but its use is s ll restricted to clear water environments.  Here we describe and test the addi on of a clear liquid op cal chamber (CLOC) to a BRUV system to improve underwater visibility when observing mo le fauna in turbid waters.  The CLOC method was trialled with respect to the ability of the system to iden fy taxa to 

species level in both controlled laboratory and fi eld condi ons across gradients of underwater visibility.  This study found that the introduc on of a CLOC to a conven onal BRUV system signifi cantly improved the ability to observe iden fying features of four fi sh species in a controlled low visibility environment.  The ability to iden fy taxa to species level in fi eld condi ons was also signifi cantly increased with the addi on of a CLOC. We conclude that the introduc on of a CLOC to a conven onal BRUV system is a reliable way of improving underwater visibility when assessing mo le fauna allowing for a more consistent iden fi ca on of taxa to species level.  This system may be applied to both marine and freshwater aqua c environments.