In the 1976-1986 period Urothoe brevicornis was observed outside the coastal area with a low distribution frequency and in low densities (maximum 140 ind./m2). A higher distribution frequency, higher densities (maximum 350 ind./m2) and observations near the western coastal zone were characteristic of the species in the 1994-2001 period.
Degraer, S.; Wittoeck, J.; Appeltans, W.; Cooreman, K.; Deprez, T.; Hillewaert, H.; Hostens, K.; Mees, J.; Vanden Berghe, E.; Vincx, M. (2006). The macrobenthos atlas of the Belgian part of the North Sea. Belgian Science Policy. D/2005/1191/3. ISBN 90-810081-6-1. 164 pp. (look up in IMIS)