INVESTIGADORES
LUPPI tomas Atilio
artículos
Título:
Effect of biodeposition of an invasive polychaete on organic matter content and
Autor/es:
BRUSCHETTI MARTIN; BAZTERRICA CIELO; FANJUL EUGENIA; LUPPI TOMAS; IRIBARNE OSCAR
Revista:
JOURNAL OF SEA RESEARCH
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Año: 2011
ISSN:
1385-1101
Resumen:
The reef-forming polychaete Ficopomatus enigmaticus is the main benthic suspension-feeding species of the 24Ficopomatus enigmaticus is the main benthic suspension-feeding species of the 24
Mar Chiquita lagoon (37¡ã 40¡ä S, 57¡ã 23¡ä W; Argentina) and exerts a strong top-down control on phytoplankton 25¡ä S, 57¡ã 23¡ä W; Argentina) and exerts a strong top-down control on phytoplankton 25
biomass. A large portion of the ingested material is rejected as faeces, and a fraction of the material filtered is 26filtered is 26
packed and discarded as pseudofaeces, which could be deposited on the sediment or horizontally displaced by 2727
water flow. In this work we evaluate the effect of this biodeposition on the organic matter (OM) content and 28flow. In this work we evaluate the effect of this biodeposition on the organic matter (OM) content and 28
productivity of the sediment between reefs. Laboratory experiments show that the OM from biodeposition 2929
was 21 times higher than the sediment between reefs and with low C per mg matter/N per mg matter. 3030
Sediment traps underneath live reefs showed higher OM content compared to traps underneath dead reefs 3131
but only in areas with low water currents, suggesting the importance of hydrodynamic conditions for this 3232
process. In situ mesocosms showed that F. enigmaticus decreased up to 45% the phytoplankton biomass, up to 33In situ mesocosms showed that F. enigmaticus decreased up to 45% the phytoplankton biomass, up to 33
50% the turbidity and up to 20% the particulate OM of the water column and, consequently enhanced up to 3434
50% the OM deposited on the bottom. But there were no differences in the OM of sediment with increased 3535
distance from the reefs. Sediment gross primary production was lower in the sediment closer to reefs, but 3636
when adults of the high-density local crab that live underneath reefs were excluded, the productivity 3737
increased, suggesting that the activity of the crabs could be counteracting the reef effect on sediment. In 3838
summary, biodeposits of F. enigmaticus can enrich the sediment, but crab activity and water currents can 39F. enigmaticus can enrich the sediment, but crab activity and water currents can 39
disperse the suspended and/or deposited material, decreasing the OM content of sediment close to the reefs. 4040
However, these effects (suspension feeding and biodeposition) are linked, and could increase flux of particles 41flux of particles 41
from water column to the bottom of the lagoon, increasing the benthic¨Cpelagic coupling.¨Cpelagic coupling.