Distribuição dos organismos bentônicos sésseis em um substrato consolidado artificial na região entremarés (Ceará, Nordeste do Brasil)

Abstract

Seaport structures provides artificial substrate in the coastal zone where organisms are established, promoting an ecosystem of distinct zonation along vertical and horizontal gradient, especially in the intertidal zone. The present study aims to identify the distribution pattern of sessile organisms in artificial consolidated substrate (pier columns) in the Pecém port region. The results indicated a tendency of increase in the occupation of the substrate and a higher upper limit reach of the organisms how closer to the sea column was. Of the species observed, appear in all columns (Brachidontes exustus, Chaetomorpha sp., Balanus amphitrite, Chthamalus bissinuatus). The polychaete Phragmatopoma cf. lapidosa was absent in columns further away from the sea and the algae Ulva spp. was absent in 70% of the columns. The most abundant species was the polychaete Phragmatopoma cf. representing 27.3% of the total number of organisms. The second largest abundance, 22.04%, was Brachidontes exustus, in sequence a barnacle Balanus amphitrite, with 15.3% and the oyster Crassostrea sp. with 13.2%. Chthamalus bissinuatus (cirripedia) represented 10.6% of organisms. As for the algae identified, about 10% of the total, 9.9% belonged to the genus Chaetomorpha sp., generally arranged in the higher places of columns, and was more abundant in columns near to the sea. The results indicate that the structure of the sessile benthic community is dominated by filtering organisms (~ 90% of the coverage percentage) with a low abundance of macroalgae. Benthic ecosystems with a three-dimensional structure dominated by sessile suspensive animals were named in the scientific literature of animal fores. Thus, it is observed that in the substrate analyzed, the columns of the port form an animal forest with competition for space along the vertical and horizontal gradient.