I have always been interested in understanding how the world works and how even the smallest animals have an impact on making the world work as it does today. It wasn't until the second year of my bachelor’s studies that I was formally introduced to the field of freshwater zooplankton ecology. My first encounter with this field took place during a course focused on ecological continuity in river ecosystems, and I became immediately captivated by it.
This interest continued to grow during my master’s thesis, which I realized in Denmark. There, I examined the relationship between ground coverage and zooplankton distribution, deepening my understanding of how terrestrial factors influence aquatic ecosystems before moving to Austria, where I shifted my focus to the study of zooplankton in alpine climates—environments characterized by extreme seasonal variability and unique ecological challenges.
The aim of my PhD project, “Phenotypic plasticity in alpine copepods: acclimatization to environmental stress on a spatio-temporal scale,” is to investigate the seasonal and spatial influences on copepod populations living in lakes above the tree line in the Austrian Alps. To achieve this, I intend to investigate which acclimation and defense strategies alpine copepods employ in response to specific and/or combined environmental stressors. I will focus especially on the impact of the temporal dynamics and spatial gradients involved in the accumulation of photoprotective compounds and the expression of molecular stress responses. Whereas, I am exploring how environmental stressors affect the phenotype and gene expression of alpine copepods, more specifically Cyclops abyssorum tatricus, a microscopic crustacean that is found in many lakes and most interestingly for me also in high-elevation Alpine lakes. My PhD is divided into three work packages: investigating seasonal variation in clear and glacier-fed turbid lakes, making a spatial comparison along a turbidity gradient, and examining the combined effect of turbidity (the cloudiness of the water measured in NTU) and ultraviolet radiation (UVR) using an experimental approach.
Being in Austria allows me to study lakes in the Alpine region, particularly during the 8-months long ice-cover period, which is still nowadays a very limited area of study. My research focuses on a specific aspect that provides a rare opportunity to study zooplankton in extreme and fluctuating conditions, particularly in lakes that are still influenced by glacial activity. I conduct monthly to bimonthly sampling over a one-year period over two lakes to capture the responses of copepods to seasonal transitions and the effect of high UVR entering the water in a clear lake, as well as the increase in turbidity, which is caused by inorganic particles from the melting glaciers, in a lake that is still in contact with the glacier.
The spatial focus of my study is on the effect of a turbidity gradient ranging from 0 (clear lakes) to 20 NTU (turbid lakes) in 12 lakes. Another exciting part of my study is creating the first de novo transcriptome for a freshwater copepod species to be used in studying the molecular response of copepods to this ever-changing environment.
My PhD aims to get a better understanding of the ecology of zooplankton in ecosystems with sharp environmental contrasts, such as clear and glacier-fed turbid alpine lakes, and to improve our knowledge of under-ice ecology.
Ambre PLACIDE
Research Group: Lake and Glacier Ecology