polychaeta

The sediment type units used were: predominantly gravel (the most abundant sediment type around Punta León colony [34 ]), rocky, characterized by the presence of reefs (i.e. isolated small rocky outcrops that extend no longer that a few metres on a flat bottom [35 ]) and grasslike where more than 50% of the seabed was covered by structures such as polychaeta tubes and algae.