Towards Non-Invasive Methods to Assess Population Structure and Biomass in Vulnerable Sea Pen Fields

Colonies of the endangered red sea penPennatula rubra ( Cnidaria: Pennatulacea) sampled by trawlingin the northwestern Mediterranean Seawere analyzed. Biometric parameters, such as total length, peduncle length, number of polyp leaves, fresh weight, and dry weight, were measured and related to each other by means of regression analysis. Adhoc modelsfor future inferencing of colonies size and biomass through visual techniques were individuated in order to allow a non-invasive study of the population structure and dynamics of P. rubra.