INVESTIGADORES
BOTTO Florencia
artículos
Título:
Cascading top-down effects on estuarine intertidal meiofaunal and algal assemblages
Autor/es:
FERNANDA ALVAREZ; SOLEDAD ESQUIUS; MARIANA ADDINO; JUAN ALBERTI; OSCAR IRIBARNE; FLORENCIA BOTTO
Revista:
JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2013 vol. 440 p. 216 - 224
ISSN:
0022-0981
Resumen:
Interactions between organisms are
important determinants of species distributions and abundances. Due to thehigh
complexity of interactions between species in natural systems, the outcome of a
given interaction can affect others, finally modifying community composition. In
South-Western Atlantic intertidal mudflats, the zonation of the burrowing crab Neohelice (Chasmagnathus) granulata and the intertidal
snail Heleobia
australis rarely overlaps, suggesting
that both speciesmight have negative interactions; and, given that both species
have different foraging strategies, these negative interactions can have top-down
impacts on community composition. Zonation patterns of both species showed that
snails are more abundant in areas without crab burrows, and field experiments revealed that snail
density correlated with a reduction in crab density and that when crabs were
excluded, snails were able to colonize those higher intertidal areas.
Bioturbation and not competition seems to drive that pattern, given that crabs
have no effects onmicroalgae, but negatively affect infaunal organisms such as
copepods, flagellates, nauplli
larvae and snails. Conversely, snails negatively affect algal assemblages,
specifically
cyanobacteria, chlorophytes, and euglenophytes, although diatoms, the most
abundant group, was not modified. Our results show
that crab?snail competition
disrupts snail herbivory upon microalgae by limiting the area over which algal
consumption occurs and highlight the complex web of interactions that
frequently regulates community structure in natural systems.