Date Awarded


Document Type


Degree Name

Doctor of Philosophy (Ph.D.)


Virginia Institute of Marine Science


Linda Schaffner


For many shallow water environments, ecosystem function depends on the cycling and flow of materials and energy between benthic and pelagic subsystems. Benthic suspension feeders often are important links between the water column and sediment in coastal ecosystems. Populations of the suspension feeding polychaete Chaetopterus pergamentaceus (previously reported as Chaetopterus variopedatus) are widely distributed along the United States East Coast, ranging from New England to Florida. This species is a structurally and functionally important member of the lower Chesapeake Bay benthic community, where it has maintained stable populations for at least the last 15 years. Little is known regarding the dynamics of this population and its role in benthic-pelagic coupling. For this study, I elucidated demographics, identified the organic matter sources fueling growth and production, determined the in situ behavior, rates and allometry of filtration, and developed an energy budget for this polychaete within the lower Chesapeake Bay estuary. Chaetopterus pergamentaceus exhibited high seasonal and interannual variability in growth, reproduction, and secondary production. High secondary production was mainly due to the rapid growth and maturation of new recruits during summer. Highly variable interannual production was due to inconsistency in recruitment success. Spatial variations in population processes, concordant with major environmental gradients, may influence the population dynamics. Locally produced organic matter, primarily fresh phytoplankton and secondarily recycled material from microbial sources with minimal to no terrestrial input, was utilized for growth and reproduction. Chaetopterus pergamentaceus has a filtration rate comparable to oysters and has the potential to transfer large quantities of matter from the water column to the benthos. This polychaete may filter a large portion of, or an amount equivalent to, the net water column community production on an annual basis. When considered on a daily basis, the potential carbon flux may be greater than net community production. Thus, this organism plays an important role in benthic-pelagic coupling in the lower Chesapeake Bay.



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