Booming or blooming? The future of lakes in a changing world


Clean water in lakes is essential for food production and drinking water, yet water quality of many lakes declines due to excessive nutrient input. Excessive nutrient input exerts high environmental pressure that ultimately causes lakes to shift from a healthy and economically productive clear water state into a blooming toxic algal soup. Attempts to reduce algal blooms have, so far, had mixed success.
Importantly, adaptation and mitigation strategies in response to algal blooms close a feedback loop in which algal blooms are both caused by, and affect environmental pressure from nutrients. Essentially, mitigation strategies aim to reduce nutrient input and adaptation strategies aim to cope with algal blooms. To date, solutions typically focus on the effect of nutrients on algal blooms thereby ignoring how algal blooms trigger nutrient management.
By neglecting part of the feedback, underlying causes of algal blooms, and their solutions are missed. Therefore, I will study the feedback loop between environmental pressure and ecosystem state to find optimal solutions to reduce algal blooms under four scenarios of mitigation and adaptation strategies. In step 1 I will develop a baseline for the effect of environmental pressure on lake ecosystem state. In step 2 I will develop a new model to optimize nutrient reductions given an available budget to study how the lake ecosystem state affects environmental pressure. In step 3 I will build the full feedback loop to identify optimal solutions for nutrient reductions for dynamic social-ecological systems.
My Veni is novel in studying a feedback loop that combines ecological responses of algae in lakes with economic optimisation. This combination allows me to develop optimal solutions for algal blooms. These solutions will help to restore lakes to their former healthy and economically productive state thereby securing future support of lakes in food and drinking water supply.


Project number


Main applicant

Dr. A.B.G. Janssen

Affiliated with

Wageningen University & Research, Omgevingswetenschappen, Water Systems and Global Change Group (WSG)


01/11/2019 to 31/10/2023