INVESTIGADORES
DALEO Pedro
congresos y reuniones científicas
Título:
Positive relationship between two conspicuous intertidal components, the sponge Hymeniacidon sp. and the algae Ulva lactuca?
Autor/es:
GASTALDI, M.; DALEO, P.; NARVARTE, M.; IRIBARNE, O.
Lugar:
Mar del Plata
Reunión:
Congreso; CERF's Inaugural International Conference of the Americas; 2012
Resumen:
Sponges and
algae are common components of intertidal ecosystems all over the world
and their ecological relationships have notbeen extensely studied. Most
of studies, performed in subtidal environments, indicate that macroalgae
out-compete and displace sponges causing their death through smothering,
shading or release of allelochemicals. The main goal of this study was to
evaluate the relationship between the sponge Hymeniacidon sp. and the algae
Ulva lactuca in a stressful intertidal environment of Patagonia. In order to
assess whether the abundance of the sponge is affected by the presence of algae
we examined, during the spring of 2011 in four sampling times, the variation in
sponges cover in plots at sites with and without algae. Also, to evaluate if
the survivorship of sponges? colonies is determined by the presence of algae,
we carried out a transplant experiment. Results showed that at in early spring,
sponges cover was higher in plots without algae. However, this difference was
substantially reduced in the subsequent time samples. The transplant experiment
showed that survivorship of sponge colonies with algae was71-78%, and that of
sponge colonies without algae was 29-32%. These results show a negative effect
of the algae on the sponge cover at the beginning of the spring, but as
temperature rises (and the dessication stress increases) the effect of the
algae becomes positive both on sponges cover and its survivorship. Future
experiments will evaluate this relationship seasonally, both in intertidal and
subtidal environments.