Aegean Bath Sponges: Historical Data and Current Status

Abstract

This study attempts to evaluate the status of the populations of bath sponges (species of the genera Spongia and Hippospongia) in the Aegean, combining historical sources dated before a series of disease outbreaks that occurred from 1986 on, unpublished data obtained during the recovery phase after the first incident, as well as a current survey of the main spongiferous beds in the area. The latter was implemented through an extensive sampling trip assisted by professional sponge fishermen, including 55 stations distributed in 17 Aegean islands. Our analysis of population and morphometric data exhibits regeneration potential for bath sponge stocks, yet highlights the contrast between their present status and that of historical times. Uniformity is not evident, as several populations retain high abundances, while simultaneously areas purportedly rich in bath sponges appear deprived. Small-scale environmental regimes in the Aegean are proposed as the shaping factors of this situation; however, the importance of additional elaborate studies and the implementation of an effective regulation scheme regarding their fisheries are stressed.