Abstract.Two geographically distantPosidoniameadows located in the Western Mediterranean Sea were analysed using SCUBA diver‐taken samples. The material was collected at depths of 1, 5, 15 and 30 m, sampling all the plants within a 400cm2area, as well as selecting bundles with epiphyticPoriferafrom a 5 m:area divided into quadrates. The effectiveness of both methods is compared, as the data in the literature were obtained from dredgings.The abundance and distribution of the seventy‐five identified species ofPoriferawere examined, taking into account the depth of the sampling stations and additional environmental factors. The two meadows studied were compared using statistical methods; some doubts are raised about the existence of a specificPoriferapopulation characteristic ofPosidoniab