Seasonal variation in δ13C and δ15N of size-fractionated plankton at a coastal station in the northern Baltic proper

作者：Carl Rolff · 发表于：Marine Ecology Progress Series · 年份：2000 · DOI：10.3354/meps203047 · 被引用次数：257 · 研究领域：Isotope Analysis in Ecology、Marine and coastal ecosystems、Marine and fisheries research

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 203:47-65 (2000) - doi:10.3354/meps203047 Seasonal variation in δ13C and δ15N of size-fractionated plankton at a coastal station in the northern Baltic proper Carl Rolff* Department of Systems Ecology, Stockholm University, 10691 Stockholm, Sweden *E-mail: crolff@system.ecology.su.se ABSTRACT: Seasonal cycles of δ13C and δ15N in dissolved organic carbon and size-fractionated plankton, ranging from bacteria to the jellyfish Aurelia aurita, were studied during a 1 yr cycle at a coastal station in the Baltic Sea. The observed isotopic changes were found with time lags in all size-fractions of plankton. The δ13C showed a bimodal cycle with 2 local maxima, the first coinciding with the spring bloom and the second with the autumn bloom. In δ15N, the annual cycle was trimodal with 3 local maxima. The first occurred in connection with the spring bloom, the second in mid-summer and the third was a broad autumn-to-winter maximum. The causes of these patterns are discussed in relation to measured oceanographic variables. In the summer, a depleted nitrogen isotopic signal was propagated through all size-classes of plankton, indicating direct or secondary utilisation of fixed nitrogen from cyanobacteria. The strength of the signal indicated that nitrogen-fixing cyanobacteria are more ecologically ...