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Levin, L, Blair N, DeMaster D, Plaia G, Fornes W, Martin C, Thomas C.  1997.  Rapid subduction of organic matter by maldanid polychaetes on the North Carolina slope. Journal of Marine Research. 55:595-611.   10.1357/0022240973224337   AbstractWebsite

In situ tracer experiments conducted on the North Carolina continental slope reveal that tube-building worms (Polychaeta: Maldanidae) can, without ingestion, rapidly subduct freshly deposited, algal carbon (C-13-labeled diatoms) and inorganic materials (slope sediment and glass beads) to depths of 10 cm or more in the sediment column. Transport over 1.5 days appears to be nonselective but spatially patchy, creating localized, deep hotspots. As a result of this transport, relatively fresh organic matter becomes available soon after deposition to deep-dwelling microbes and other infauna, and both aerobic and anaerobic processes may be enhanced. Comparison of tracer subduction with estimates from a diffusive mixing model using Th-234-based coefficients, suggests that maldanid subduction activities, within 1.5 d of particle deposition, could account for 25-100% of the mixing below 5 cm that occurs on 100-day time scales. Comparisons of community data from the North Carolina slope for different places and times indicate a correlation between the abundance of deep-dwelling maldanids and the abundance and the dwelling depth in the sediment column of other infauna. Pulsed inputs of organic matter occur frequently in margin environments and maldanid polychaetes are a common component of continental slope macrobenthos. Thus, the activities we observe are likely to be widespread and significant for chemical cycling (natural and anthropogenic materials) on the slope. We propose that species like maldanids, that rapidly redistribute labile organic matter within the seabed, probably function as keystone resource modifiers. They may exert a disproportionately strong influence (relative to their abundance) on the structure of infaunal communities and on the timing, location and nature of organic matter diagenesis and burial in continental margin sediments.

Bridges, TS, Levin LA, Cabrera D, Plaia G.  1994.  Effects of sediment amended with sewage, algae, or hydrocarbons on growth and reproduction in two opportunistic polychaetes. Journal of Experimental Marine Biology and Ecology. 177:99-119.   10.1016/0022-0981(94)90146-5   AbstractWebsite

The effects of organic- (sewage and blue-green algae) and hydrocarbon- (no. 2 fuel oil) amended sediments on growth schedules, age and size at maturity, fecundity, and reproductive output were examined for the opportunistic polychaetes Streblospio benedicti Webster and Capitella sp. 1. The two species responded very differently to the amended sediments. For S. benedicti, asymptotic size was reduced and age at first reproduction occurred later in the algae and hydrocarbon treatments compared to the marsh mud only and sewage treatments. Organic- and hydrocarbon-amended sediments did not affect per brood measures of fecundity or C and N investment in S. benedicti. In contrast, Capitella sp. I exhibited strong, positive responses to the organically amended sediments; this was seen in terms of more rapid growth (2 x), younger age at first reproduction (50%), larger asymptotic size (6 x), and higher per brood fecundity and C and N investment (4 x). Reproductive output, a relative measure of reproductive investment, was not directly affected by treatments in either species. For Capitella sp. I in organically enriched settings, the benefits of larger body size appear to include higher per brood fecundity without increasing the relative cost (in terms of reproductive output) of producing a brood of young. The population explosions of Capitella sp. I in response to organic enrichment are the result of earlier reproduction and increased body size and fecundity. Positive population-level responses of S. benedicti to contaminated sediments may be the result of its ability to tolerate conditions that other members of a community do not.