Spatial and temporal resolution of carbon fluxes in a shallow coastal ecosystem, the Kattegat

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 252:35-50 (2003) - doi:10.3354/meps252035 Spatial and temporal resolution of carbon fluxes in a shallow coastal ecosystem, the Kattegat Jacob Carstensen1,*, Daniel Conley1, Bärbel Müller-Karulis2 1Department of Marine Ecology, National Environmental Research Institute, PO Box 358, 4000 Roskilde, Denmark 2University of Latvia, 6 Daugavgrivas St., 1007 Riga, Latvia *Email: jac@dmu.dk ABSTRACT: Spatial and temporal variations in pelagic carbon fluxes were examined by means of a large-scale and long-term monitoring data set from the Kattegat, a shallow marginal sea impacted by man-induced eutrophication. Flows of carbon, nitrogen and phosphorus in the upper mixed layer (0 to 10 m) were estimated from a simple descriptive model using measurements of primary production, temperature, and phytoplankton/zooplankton biomass as input variables. For all years combined, annual primary production at coastal stations (171 gC m-2 yr-1; 8 stations) was almost twice that at the deeper open-water stations (105 gC m-2 yr-1; 5 stations), which resulted in an annual primary production of 116 gC m-2 yr-1 for the region as a whole during the entire study period (1989 to 1997). Interannual variation in primary production was substantially smaller than the between-station variation. The phytoplankton spring bloom contributed substantially to annual production (10 to 20%), but the magnitude and timing were highly variable between years. Respiration accounted for on average 12% of the measured primary production. Annual sedimentation was estimated at 55 gC m-2 yr-1, equivalent to 54% of net primary production. The estimated new production was significantly related to nitrogen loading from the land and atmosphere, and a regression analysis predicted declines of between 20 and 47% in annual net primary production from a 50% reduction in nitrogen loading. Carbon and nutrient fluxes are consistent with those of earlier studies from the Kattegat based on small-scale and short-term data sets. However, combining monitoring data with a budget model greatly improved data resolution in both time and space. Estimated C/N/P fluxes from the model can act as reliable indicators for assessing the state of eutrophication in the Kattegat and other inland seas impacted by man-induced nutrient loading. KEY WORDS: Primary production · Respiration · Sedimentation · Budget models · Monitoring data · Eutrophication · Kattegat Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 252. Online publication date: April 30, 2003 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2003 Inter-Research.