Paul Shannon 

Abstract

Harmful algal blooms (HABs) represent a significant, pervasive threat to global aquatic ecosystems, impacting ecology, economies, and ultimately, overall human health. Hepatotoxic blooms in particular, such as Microcystis blooms, are known to produce a classification of cyanotoxins known as the Microcystins (MCs), of which there are over 270 recognized variants (Yang et al., 2020). MC-LR, one of the most common and most deadly hepatotoxins, is a known liver tumor enhancer. Following injection with a lethal dose of MC-LR, liver damage and cell death can be seen microscopically in as soon as twenty minutes (OEHHA, 2009). This study investigates the potential of the common water hyacinth (Eichornia crassipes) in mitigating a Harmful Microcystin Bloom through rhizofiltration, a phytoremediation process involving the uptake of nutrients, such as phosphates, through the macrophyte's root system. The presence of water hyacinth, as supported by the data, influences cyanobacterial growth, indicated by fluctuations in turbidity. Secchi depth measurements unexpectedly showed a decrease in water clarity within groups with water hyacinth compared to the control group; however, remediation was observed as the algal scum visibly decreased and PO4 / TDS levels decreased. Despite supporting the hypothesis in part, the study acknowledges the complexity of the constructed system, and thus, further controlled research may be necessary. Factors such as water hyacinth growth and shedding, potential shading effects, dissolved oxygen levels, and the settling of algae should be considered in future investigations. The study emphasizes the need for a balanced approach to all future water hyacinth applications, ensuring its effective utilization while preventing issues such as hyacinth matting.