Effects of macroalgae on the recruitment, growth, and body condition of an invasive reef forming polychaete in a south-western Atlantic coastal lagoon

M CIELO BAZTERRICA; MARTIN BRUSCHETTI; FERNANDA ALVAREZ; OSCAR IRIBARNE; FLORENCIA BOTTO

JOURNAL OF SEA RESEARCH

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2014 vol. 88

1385-1101

Species interactions could mediate species invasive processes. InMar Chiquita coastal lagoon (37° 40′S, 57° 23´W, Argentine), the invasive reef building polychaete Ficopomatus enigmaticus (Fauvel 1923) enhances the biomass of the red alga Polysiphonia subtilissima Montagne 1840 on reef surfaces, and excludes green macroalgae (mainly Cladophora sp. Kützing, 1843) from sediment between reefs. In turn, macroalgae could have several community structuring effects (e.g., as food or by competing for space). Therefore,   macroalgae may affect F. enigmaticus. To evaluate this hypothesis we studied (1) the interaction between macroalgae and F. enigmaticus during the colonization of new substrates and (2) the effects of macroalgae on the recruitment, growth, and body condition of F. enigmaticus. Field sampling and experiments suggested a lack of competition on  newsubstrates. However, therewas a positive effect ofmacroalgae on F. enigmaticus during thewarmseason, since its recruitment, tube length, and body condition were higher in areas with macroalgae on reef surfaces.Considering that previous studies showed that reefs  positively affect macroalgae, our results suggest that there is a positive feedback on F.  enigmaticus created bymacroalgae on established reefs and during the reefs´ growing season. This interaction may contribute to the maintenance and growth of established reefs.