Towards effective management of the marine-origin Prymnesium parvum (Haptophyta): A growing concern in freshwater reservoirs?

Abstract

Freshwater ecosystems are highly susceptible to harmful algal blooms (HABs), which are often caused by monospecific dense blooms. Effective preventive management strategies are urgently needed to avoid wide-ranging and severe impacts often resulting in costly damage to resources and unsustainable management options. In this study, we utilized SDM techniques focused on Prymnesium parvum, one of the most notorious HABs species worldwide. We first compare the climatic space occupied by P. parvum in North America, Europe and Australia. Additionally, we use MaxEnt algorithm to infer, for the first time, the potentially suitable freshwater environments in the aforementioned ranges. We also discuss the risks of invasion in reservoirs - prone habitats to persistent blooms of pests and invasive phytoplanktonic species. Our results show populations with distinctive niches suggesting ecophysiological tolerances, perhaps reflecting different strains. Our model projections revealed that the potential extent for P. parvum invasions is much broader than its current geographic distribution. The spatial configuration of reservoirs, if not sustaining dense blooms due to non-optimal conditions, favors colonization of multiple basins and ecoregions not yet occupied by P. parvum. Our models can provide valuable insights to decision-makers and monitoring programs while reducing the resources required to control the spread of P. parvum in disturbed habitats. Lastly, as impact magnitude is influenced by toxicity which in turn varies between different strains, we suggest future studies to incorporate intraspecific genetic information and fine-scale environmental variables to estimate potential distribution of P. parvum.

Keywords: Biopollution; Freshwater reservoirs; Invasion; Prymnesium parvum; SDMs.