Identifying drivers of sub-surface chlorophyll peaks in lakes

The vertical distribution of chlorophyll fluorescence, a proxy for chlorophyll a concentration and algal biomass, has important implications for the structure and function of lake ecosystems by regulating vertical gradients in primary production, net ecosystem production, diversity and food web interactions. Many lakes exhibit sub-surface (often meta-limnetic) peaks in chlorophyll, yet the drivers of this phenomenon are not well understood and the diversity of vertical distributions is poorly characterized. This project is using vertically resolved profiles of chlorophyll fluorescence to understand the drivers of variation in the distribution of chlorophyll in the water column across GLEON and GLEON-affiliated lake sites. Data from > 100 lakes where chlorophyll fluorescence, temperature, and light profiles have been collected along with associated sensor, lake morphology, and water quality characteristics are being used to address these research topics. The project is being led by Taylor Leach, Beatrix Beisner and Cayelan Carey.