DISTRIBUTION OF BENTHIC INVERTEBRATES IN THE BEAGLE CHANNEL, ARGENTINA

DIEZ M.; ROMERO M.C.; OBENAT, S.; ALBANO, M.; TAPELLA, F.

Anales Instituto Patagonia (Chile)

Universidad de Magallanes

Año: 2009 vol. 37 p. 29 - 40

0718-686X

Bathymetric and spatio-temporal distributions of both abundance and biomass as well as secondary production of benthic invertebrates in the Beagle Channel were determined. The sampling stations were seasonally placed in three different areas in the Beagle Channel at two depth ranges, 15-40 m and 70-259 m. A total of 32,686 specimens distributed in 30 taxonomic groups were identified. In addition, 4 taxa were quantified only in terms of biomass. The invertebrate abundance and biomass were different with depth. Secondary production at this range was 0.59 ±0.51 kJ·m-2 year-1 whereas it decreased to 0.09 ±0.08 kJ·m-2 year-1 at 70-259 m. In contrast to secondary production, P/B ratio showed a positive increment with depth. Furthermore, seasonal variations were not observed in secondary production of the macrozoobenthos. Parameters directly associated with depth could be involved in structuring the macrobenthic assemblages in the Beagle Channel.