Influence of a burrowing, metal-tolerant polychaete on benthic metabolism, denitrification and nitrogen regeneration in contaminated estuarine sediments. Joanne L. Banks, D. Jeff Ross, Michael J. Keough, Catriona K. Macleod, John Keane, Bradley D. Eyre. Marine Pollution Bulletin 68 (2013) 30–37.
We investigated the effects of the burrowing cirratulid polychaete Cirriformia filigera (Delle Chiaje, 1828)
on benthic respiration and nitrogen regeneration in metal-contaminated estuarine sediments using laboratory
mesocosms. C. filigera is a dominant component of assemblages in the most severely contaminated
sediments within the Derwent estuary, southern Australia. In the presence of C. filigera sediment
O2 consumption doubled, with approximately 55% of this increase due to their respiration and the
remaining 45% attributable to oxidation reactions and increased microbial respiration associated with
burrow walls. Combined NO3 and NO2 fluxes were unaffected. The addition of labile organic matter
did not affect benthic fluxes, in the presence or absence of C. filigera, presumably due to the short timeframe
of the experiment and naturally enriched test sediments. The results suggest that a combination of
tolerance and burrowing activity enables this species to provide an ecosystem service in the removal of N
from contaminated sites.