Algal bloom response and risk management: On-site response tools

Area of Science:

• Environmental Science
• Public Health
• Analytical Chemistry

Background:

• Harmful algal blooms (HABs) caused by cyanobacteria produce microcystin toxins, posing risks to water safety and public health.
• Current analytical methods for microcystin detection are time-consuming, hindering rapid risk assessment and management.
• Commercial test kits offer a potential solution for faster toxin detection, but require rigorous field validation.

Purpose of the Study:

• To evaluate the performance of two commercial microcystin test kits in real-world conditions.
• To compare kit results against established laboratory analyses (ELISA and PPIA) for accuracy and reliability.
• To determine the suitability of these kits for routine monitoring and risk management of HABs.

Main Methods:

• Two commercial microcystin test kits with different detection ranges were field-tested.
• Samples with diverse water quality, matrices, and bloom compositions were analyzed.
• Kit performance was compared against Enzyme-Linked Immunosorbent Assay (ELISA) and Protein Phosphatase Inhibition Assay (PPIA) laboratory results.

Main Results:

• Both kits accurately distinguished between high (>10 μg/L MCequiv) and low/no toxin samples.
• A significant rate of false positives (32%) and some false negatives (8%) occurred for toxin levels between 1-5 μg/L.
• The kits demonstrated potential for screening, with successful integration into a municipal beach monitoring program.

Conclusions:

• Commercial microcystin test kits are valuable tools for initial screening and informing risk management decisions, such as beach closures.
• Results from these kits should be confirmed with more rigorous laboratory testing for intermediate toxin levels (1-5 μg/L).
• The validated kits can be effectively incorporated into routine public health monitoring programs for harmful algal blooms.