ALVAREZ Maria Fernanda
Factors controlling macroalgae assemblages in a Southwest Atlantic coastal lagoon modified by an invading reef forming polychaete
BAZTERRICA, MARÍA CIELO; ALVAREZ, MARÍA FERNANDA; BRUSCHETTI, CARLOS MARTÍN; HIDALGO, FERNANDO JOSÉ; FANJUL, MARÍA EUGENIA; IRIBARNE, OSCAR; BOTTO, FLORENCIA
JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY
ELSEVIER SCIENCE BV
Lugar: Amsterdam; Año: 2013 vol. 443 p. 169 - 177
In the Mar Chiquita coastal lagoon (37° 40′S, 57° 23°W, Argentina), the invasive reef building polychaete Ficopomatus enigmaticus, change the composition and abundance of macroalgae by providing habitat tosome species and by excluding others. The magnitude of these effects may be regulated by consumers and nutrients availability. Here we evaluate the relative importance of consumers and nutrients in controllingmacroalgae development on the reefs, and on the sediment in areas without reefs. Experiments showed that: (1) large consumers (birds, fishes and crabs) had no effect on red (Polysiphonia subtilissima) andgreen (Cladophora sp.) macroalgae on reefs; (2) large consumers had positive effect on green macroalgae development on the sediment of areas without reefs, probably by enhancing the availability of bivalve shellsfor macroalgae attachment; (3) small consumers (amphipods, hydrobiid snails and crabs) had negative effect on green macroalgae development, probably by direct consumption; (4) small consumers had positive effecton the biomass of the red macroalga P. subtilissima; and (5) nutrient had no effect on macroalgae. These interactions would determine the abundance and the spatial distribution of macroalgae (e.g., patchiness).Consequently, the effect of an invader ecosystem engineer in the composition of species assemblages may be mediated by other community structuring forces, which in turn may have different effects according totheir interaction with the invader.