Cyanobacteria (“bluegreen algae”) often proliferate at the same time and under similar conditions that are favourable for internal phosphorus (P) loading from lake bottom sediments. Internal loading as P released from anoxic sediment surfaces often represents the main summer P load to lakes. Because of its high biological availability, the lack of dilution, and the timing, it can have an immense effect on summer-fall water quality of a lake, reservoir, or pond.
In this workshop correlations and coincidences, as well as limnological reasoning is provided in support of the hypothesis that cyanobacteria blooms (in general and for the recently increased frequency), are related to increases in internal P loading. While this workshop is based on my past Internal Load Workshop (2003–2018) much material has been added about the possible links between sediment released P and cyanobacteria blooms. To provide room, some of the more basic limnological and modelling sections of the previous workshop have been shortened.
Nonetheless, ways of quantifying internal load in polymictic and stratified lakes are still presented, sometimes in a stepwise fashion, where missing data may be predicted by subsidiary models. Applications regarding lake quality assessment and trophic state, and an introduction into the theory of lake restoration will be provided. Each workshop topic will include a description of the theory and presentation of case studies covering US, Canadian, and European lake assessment and restoration projects listed at http://www.fwr.ca.
Presenter
Gertrud K. Nürnberg, Ph.D. (McGill, Quebec) is the principal of Freshwater Research, a limnological company focusing on restoration and modeling of eutrophic lakes and reservoirs. She is specialized in internal processes in eutrophic lakes such as internal phosphorus loading and hypoxia and has more than 35 years of experience working with lake associations, governmental agencies, engineering companies, and the private sector in the US, Canada, and Europe. She has published comparative research and empirical lake models on phosphorus, iron, and anoxia and on lake management techniques in numerous scientific journals and was an associate editor of the NALMS journal, Lake and Reservoir Management, where she is still actively involved in the peer-review process.