Seasonality of community structure and carbon flow in Narragansett Bay sediments

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1984

OSTI ID:6872684

Rudnick, D T

Seasonal patterns of benthic community dynamics and the pathways of detrital decomposition in Narragansett Bay were examined. Benthic meiofauna and macrofauna exhibited a pronounced seasonality, with peak abundances in the late spring and minima in the late summer. This pattern was most pronounced for surface dwelling fauna, particularly harpacticoid copepods. These results were attributed to the seasonality of detrital inputs to the sediment and the fate of these inputs. A six month study in which {sup 14}C-sodium bicarbonate was added to a large (13 m{sup 3}) microcosm enabled the author to observe pathways of carbon flow. Half of the labeled organic carbon that was deposited on the sediment during the winter and spring was found in the sediment in July. At least 20 gC/m{sup 2} had accumulated since December. Within the sediment, the existence of two discrete food webs was distinguished by measurement of faunal specific activity. Surface fauna, dominated by the meiofauna, exclusively assimilate fresh (labeled) organics, while subsurface fauna (meiofauna and macrofauna) predominantly assimilated older, non-labeled organics for the duration of the study. Only the subsurface food web had access to the storage of buried detritus. While there was a surplus of detritus for both food webs during the winter and spring, the authors expect that benthic respiration rates exceed organic deposition rates during the summer. Detrital storage may be critical for the survival of the fauna through the summer.

• Research Organization: Rhode Island Univ., Kingston, RI (USA)
• OSTI ID: 6872684
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540311* -- Environment
Aquatic-- Basic Studies-- Radiometric Techniques-- (1990-)
ACID CARBONATES
ALKALI METAL COMPOUNDS
AQUATIC ORGANISMS
BAYS
BENTHOS
BIODEGRADATION
CARBON 14 COMPOUNDS
CARBON CYCLE
CHEMICAL REACTIONS
DECOMPOSITION
DETRITUS
FOOD CHAINS
LABELLED COMPOUNDS
NORTH AMERICA
POPULATION DYNAMICS
SEASONAL VARIATIONS
SEDIMENTS
SODIUM COMPOUNDS
USA
VARIATIONS