| Water category: | Lake |
| Pressure categories | Nutrients |
| Pressure detail | Commonly termed eutrophication. Usually increase in phosphorus load. |
| Specific Index | Proportion of cyanobacteria (exc. Chroococcales, but with Microcystis & Woronichinia) on total algal biovolume |
| Brief text description | The proportion of cyanobacteria shows a non-linear increase ('threshold') with increasing eutrophication. |
| Long text description | Filamentous and colonial cyanobacteria (such as Anabaena, Aphanizomenon, Microcystis, Planktothrix) are characterized by a high efficiency for using light, thus they may withstand low light conditions better than many common taxa. Moreover, they are poor quality foood or even toxic for grazers, making them less affected by zooplankton grazing. Both factors make them superior competitors under eutrophic conditions. Thus, eutrophication causes often (but not always) dominance by cyanobacteria. |
| History of development | Qualitiative relationship is known for long time. Downing et al. have quantified th relationship in a global dataset. Within the REBECCA project, the relationship was analysed for separate regions and lake types. |
| References | DS Rawson. (1956) Limnol. Oceanogr. 1(1) 18-25. JA Downing et al. (2001) Can. J. Fish. Aquat. Sci. 58: 1905–1908. R. Ptacnik et al. (2007) Aquat. Ecol.(in rev.) |
| Geographic region (GIG) - L | LNO - Northern LCE - Central+Baltic |
| Ecoregion - LR | 22. Fenno-Scandian shield |
| Country | D Germany A Austria DK Denmark FIN Finland S Sweden LV Latvia NO Norway XX Other country |
| Geographical location of source data | Multi-national |
| Reference conditions | Considered |
| Development | Rebecca |
| Uncertainty | Considered |
| Link to document store | Yes |
| BMW Toolbox | No |
| Entry status | Unvalidated |
| Attachment 1 | proportion of cyanobacteria [16025 bytes] |