Datasets for: Light and temperature as triggers for surface filamentous green algal blooms in shallow freshwater systems

Datasets used in the analysis of the jounral artical: Light and temperature as triggers for surface filamentous green algal blooms in shallow freshwater systems (Kemp et al, In review) Blooms of filamentous green algae (FGA) form dense mats at the surface of shallow freshwaters and have multiple negative impacts on aquatic ecosystem functions, services and aesthetics. Although nutrient enrichment in freshwaters is a primary driver of excessive FGA growth, much less is known about other abiotic factors controlling bloom growth rate, extent and timing. We performed a series of indoor mesocosm (Limnotron) experiments to investigate the effects of photosynthetically active radiation (PAR) irradiance, photoperiod and water temperature on the growth and surface bloom formation of FGA using underwater and surface photography. The results revealed that a minimum daily light integral of ~13.2 mol m-2 day-1 (a combination of PAR irradiance measured at the water surface and photoperiod) was required for bloom formation and substantial FGA growth. Surface blooms did not occur at short daylengths (i.e. 8 hours), whereas a longer daylength (i.e. 16 hours) allowed more time for photosynthetically derived gas bubbles to accrue in the FGA masses, making them rise to the water surface through buoyancy. We also found that temperatures between 16 – 22°C were optimal for FGA to form surface blooms. As freshwater ecosystems are increasingly impacted by climate change, our study sheds new light on factors affecting the occurrence of surface blooms and helps identify when waterbodies may be at risk of FGA blooms in the future. The datasets for the above experiments include: FABLIGHT_FGA_area.csv FABLIGHT_FGA_final_biomass.csv FABLIGHT_limnotron_chlorophyll_a.csv FABLIGHT_limnotron_nutrients.csv FABLIGHT_limnotron_oxygen.csv Each file has a READ ME tab which includes asociated metadata for each dataset.