Resource biology of Pterocladia capillacea (Gelidiales,Rhodophyta) populations in Brazil

Pterocladia capillacea has been already exploited in Brazil and Uruguay, but exploitation was discontinued due to source depletion. Our attempts to cultivate this species in the sea, or in tanks, gave poor results. In this communication we present some ecological data as a contribution to evaluate the possibility of a production increase in natural beds on the southeast coast of Brazil.Our results show that: (i) the populations are perennial varying from 323 (i.c._0.05 = 51) to 600 (i.c._0.05 = 78) g dry weight throughout the year; (ii) horizontal distribution is affected by irradiance, with higher biomass in shaded areas and by water movement, with higher biomass in intermediate sites; (iii) vertical distribution is limited above by desiccation and below by herbivores — sea urchins removal increases cover by 20–50%; (iv) Sargassum vulgare is the main competitor for space, and its removal on areas of contact between both populations increases coverage of P. capillacea by ca 80%.