INVESTIGADORES
GIBERTO Diego Agustin
congresos y reuniones científicas
Título:
Structure and spatial distribution of benthic assemblages of a coastal area of Argentina (El Rincón, 38°S-42°S)
Autor/es:
GIBERTO, D.A.; CUEVILLAS, A.; GARCÍA ALONSO, V.; BREMEC, C.S.
Lugar:
Punta del Este
Reunión:
Congreso; XV Congreso Latinoamericano de Ciencias del Mar (COLACMAR); 2013
Resumen:
This study characterizes the structure and spatial distribution of benthic assemblages in a wide marine coastal area of the Argentinean shelf, “El Rincón”, between 7 and 50 m depth. As the study area is subjected to demersal fisheries, information is given about the feeding grounds of many of the benthofagous commercial species, mainly crustaceans and fishes. Samples were collected during 1994 and 1999 (INIDEP Cruises, by means of a Picard dredge (38 x 95 cm mouth), and sorted on board (0.5 mm mesh size). Bottom salinity, bottom temperature and depth were registered with a Sea Bird-19 CTD (“Conductivity-Temperature-Depth profiler”). Sediments were taken with snapper Dietz-Lafond (0.02 m2) to conduct granulometric analysis. Species were identified and quantified (abundance and biomass) at laboratory. Univariate (Diversity, Dominance) and Multivariate Analyses (CLUSTER, MDS, ANOSIM, BIO-ENV) were used. During 1994, 76 taxa were collected: molluscs more diversified with 28 species, followed by polychaetes and crustaceans. During 1999, a total of 195 taxa were identified, in this case crustaceans represented by 73 taxa, followed by mollusks and polychaetes. In general, shallower and deeper stations were clustered in two different groups and diversity was higher in the latter area according to the analyses. Mytilus e. platensis, Corbula pulchella and Encope emarginata were the conspicuous species that most contributed to differences between years. Bottom temperature (correlated with depth), gravel and mud contents best explained the distribution of samples in the whole area. Results are discussed taking into account different considerations. Although taxonomical experience was undoubtedly enhanced, the external area was mostly covered in 1999, year when total species richness was highest.