Ecological impacts of two non-indigenous macroalgae on an urban rocky intertidal shore.

M. G. PALOMO; MARIA BAGUR; MARINA QUIROGA; SABRINA SORIA; ANA BUGNOT

MARINE BIOLOGY

SPRINGER

Lugar: Berlin; Año: 2016 vol. 163 p. 1 - 12

0025-3162

Non-indigenous marine species often change theabundance and diversity of native species in coastal ecosystems.On the SW Atlantic coast, the macroalgae Ahnfeltiopsissp. (Rhodophyta, Phyllophoraceae) and Schizymeniadubyi (Rhodophyta, Schizymeniaceae) have invadedthe intertidal rocky shore of Mar del Plata, Argentina(38°S, 57°W). To study the spread and ecological associationsof these invasive species, algal abundance, biomassand biodiversity of benthic assemblages at three differenttidal levels were examined during five years. Sparse Ahnfeltiopsissp. thalli (3 % cover) were detected in February2007 at the three tidal levels. By January 2011, its coverhad increased to 11 %, while its biomass showed a 27-foldincrease. S. dubyi was detected at the lower intertidal levelin January 2010 with a cover of 2 %. By January 2011, ithad increased to 5 % and spread to the other intertidal levels.The presence of these two non-indigenous algae modifiedthe substrate and the structure and composition of thebenthic assemblage. The constant increase in the algalbiomass and presence along the intertidal suggest that theeffect will be greater in the future. Moreover, the effects ofthese exotic algae could potentially displace Brachidontesrodriguezii?an important ecosystem engineer that createsmicrohabitat for a large number of organisms on these shores.