Greater knowledge of the macroalgae from rocky shores is essential to monitor and manage marine coastal conservation units. Previous surveys of the coastal zone of the Picinguaba unit in the Serra do Mar State Park (PESM), Ubatuba, northern São Paulo state, list macroalgal species from the rocky shores and the mangroves of Fazenda Inlet. The present study aimed to improve the taxonomic survey of seaweeds from the Picinguaba unit and to evaluate the suitability of sampling methodology for rocky shore communities in this conservation unit. Thirteen sampling stations, situated between Almada and Cambury Headlands, were studied in summer 2007; this part of the PESM coastal zone is subject to anthropogenic interference. We carefully searched for macroalgae in different rocky habitats, from the sublittoral fringe towards the sand domain. Aiming to standardize sampling effort at each station, the same specialist searched for macroalgae over a 20 m horizontal extension of the rocky shore, for one hour, by apnea diving. 128 infrageneric taxa were identified (80 Rhodophyta, 22 Ochrophyta and 26 Chlorophyta). Callithamniella flexilis Baardseth, Cryptonemia seminervis (C. Agardh) J. Agardh, Cladophora pseudorupestris C. Hoek and Cladophora cf. pygmaea Reinke are new records for the coast of São Paulo state. These species are described and illustrated here. Sixty four species are new occurrences for the rocky shores of PESM. Taking into account other studies, carried out on the northern São Paulo coast and on the southernmost Rio de Janeiro coast, the sampling effort of the present study can be considered suitable for taxonomic surveys, because it produced a comparable number of macroalgal species. In conclusion, for monitoring purposes of the Picinguaba coastal environment, we recommend sampling rocky shore macroalgae yearly, in the summer, using the methodology described in this paper.
macroalgae; floristic survey; conservation unit; rocky shores
