A description is given of the response of phytoplankton composition to eutrophication caused by an increase in fresh water flux in four Empordà salt marsh basins. Cyanobacteria and mixotrophic phytoplankters (especially haptophytes and dinoflagellates) are the most abundant organisms in these basins. Under stable conditions, cyanobacteria take competitive advantage of the lack of inorganic nitrogen caused by confinement. Mixotrophs dominate coinciding with water inputs. The importance of the allochthonous supply probably favours mixotrophs, which may also take nitrogen heterotrophically. The phytoplankton-invertebrate biomass ratio (P/I) and the chlorophyll-phytoplankton biovolume ratio (Chl/BV) respond differently to stabilisation of freshwater input, depending on the degree of eutrophy of the basins. Thus, in more eutrophic basins flux regulation causes an increase in P/I and a decrease in Chl/BV, indicating higher density of mixotrophs and lesser density of invertebrates. Less eutrophic basins respond in the opposite fashion.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 36 • No. sp1