Webbläsaren som du använder stöds inte av denna webbplats. Alla versioner av Internet Explorer stöds inte längre, av oss eller Microsoft (läs mer här: * https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Var god och använd en modern webbläsare för att ta del av denna webbplats, som t.ex. nyaste versioner av Edge, Chrome, Firefox eller Safari osv.

Molecular size of riverine dissolved organic matter influences coastal phytoplankton communities

In English

Författare

Summary, in English

Dissolved organic matter (DOM) concentrations in many northern European freshwater systems have been increasing during the past decades. DOM affects the marine plankton community where rivers discharge into the sea. Large DOM molecules have been suggested to be more available to aquatic plankton than smaller ones due to their more recent origin in the degradation process. In this study, we investigated the effect of riverine DOM molecular size on coastal plankton with the hypothesis that nitrogen associated with large molecules stimulates the plankton more than nitrogen in smaller molecules. Three size fractions of riverine DOM were isolated with tangential ultrafiltration and introduced at similar nitrogen concentrations to mesocosms with a natural coastal marine plankton community under nitrogen limiting conditions. The results show that growth of bacteria and dinoflagellates, but not diatoms, was stimulated by addition of large DOM molecules. Even though organic nitrogen concentrations tended to decrease more in large DOM treatments compared to smaller DOM treatments, no significant differences were detected. However, proteolytic enzyme activities were elevated in treatments with the largest DOM molecules, suggesting that more organic nitrogen was utilized in this treatment. We suggest that input of larger river DOM molecules to nitrogen limited coastal systems may influence the composition of the coastal phytoplankton community in favour of dinoflagellates.

Publiceringsår

2010

Språk

Engelska

Sidor

17-25

Publikation/Tidskrift/Serie

Marine Ecology - Progress Series

Volym

409

Dokumenttyp

Artikel i tidskrift

Förlag

Inter-Research

Ämne

  • Ecology

Nyckelord

  • Molecular size
  • DON
  • River
  • Dissolved organic matter
  • DOM
  • Marine
  • phytoplankton

Status

Published

Forskningsgrupp

  • Aquatic Ecology

ISBN/ISSN/Övrigt

  • ISSN: 1616-1599