Revista Chilena de Historia Natural 76 (3): 401-415, 2003
RESEARCH ARTICLE
Composition, structure and energy flux of the meiobenthos off central Chile
The general objective of this study was to determine the structure of metazoan meiofauna
(at a high taxonomic level) and to estimate its role in the energy flux of the benthic sub system off Concepción, Chile (~36º30’ S).
Samples were collected in May and November 1997 and May 1998 at five sites located at the: inner Bay of Concepción (28 m), bay
mouth (35 m), inner-shelf (64 m), mid-shelf (88 m) and outer-shelf (120 m). The study period coincided with the El Niño 1997-1998
(EN) event. The diversity of the meiobenthos was low, but density and biomass were moderate to high compared with average values
reported for muddy sub-littoral environments elsewhere. Nematodes were the dominant group, with over 95 %
(10<sup>3</sup>–10<sup>4</sup> ind 10 cm<sup>–2</sup>) of the total density, followed by copepods
and polychaetes. Highest densities and biomasses were always found at the bay-mouth, followed by the inner-bay and the inner-shelf,
while the lowest values occurred at the mid- and outer-shelf. Off Concepción, the meiofauna plays an important role in the energy flux
through the benthic sub-system. Indeed, the meiofauna could be converting to biomass and remineralizing in the inner-bay and bay-
mouth up to 36 and 45 %, respectively, of the organic carbon reaching the sediments from the water column.
Key words:
meiofauna, secondary
production, energetic flux, El Niño, central Chile
