# Which Factors Move The Phytoplankton?

Tudi Guillou, Vincent Bertrin, Sébastien Boutry, Aurélien Jamoneau

► To cite this version:

Tudi Guillou, Vincent Bertrin, Sébastien Boutry, Aurélien Jamoneau. Which Factors Move The Phytoplankton?. e-TOX 2025: journées scientifiques 2025, May 2025, Cestas Gazinet, France. .
hal-05086861

HAL Id: hal-05086861

https://hal.inrae.fr/hal-05086861v1

Submitted on 27 May 2025

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## CONTEXT

Cyanobacterial blooms are increasingly occurring on a global scale and pose a significant threat to ecosystem services. Prevailing western winds and associated wave action can play a crucial role in displacing phytoplankton communities across the lake. This study analyzes the effects of western wind and waves on the spatio-temporal distribution and concentration of phytoplankton.

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## TIME SERIES

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### EDI¹

Effective Displacement Index measures the cumulative wind speed weighted over several days.

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### ARIMAX

Is a time series model using exogenous variables to test the effect of a potential wind lag (EDI) on the concentration of phytoplankton groups.

## SPATIAL

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### KEDDY²

Evaluate wind exposure across the horizontal water surface of the lake using fetch and wind data.

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### GAM

The Generalized Additive Model will be used to show how spatial environmental variables (Keddy, temperature) influence the distribution of phytoplankton.

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