New Chromatography Method Detects Fish Toxins from Algae Blooms

Some harmful algal blooms create toxins that can hurt animals and people, who are usually exposed to them by eating seafood. Right now, because we do not know enough about how much of these toxins build up in fish, researchers are seeking fast, dependable ways to check toxin levels in different types of larger fish (the ones higher up the food chain), so a conclusion can be come to as to why fish are dying, as well as to stop people from getting sick from tainted seafood. In one study, a method was developed for the extraction and cleanup of phycotoxins from plasma of juvenile sandbar sharks (Carcharhinus plumbeus) using ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). A paper based on this work was published in the journal ACS Omega.¹

What is a Harmful Algal Bloom (HAB), and Why Is It Becoming a Bigger Problem?

A harmful algal bloom (HAB) occurs when tiny algae or cyanobacteria grow out of control and end up hurting the plants and animals around them. These blooms can damage fish and wildlife populations, hurt fish farms and fishing industries, and even affect tourism and human health. In the United States, many different types of algae can cause these blooms, and they can happen in freshwater, saltwater, or the brackish water where the two mix. Over the past several decades, these blooms have been happening more often and spreading over larger areas, likely due in part to human activities like nutrient pollution (from fertilizer runoff, for example), the growth of fish farming, and warming ocean temperatures. As the climate continues to change, scientists expect these harmful blooms to become even more of a problem.^2-4

Which Cleanup Method Works Best for Detecting Algal Toxins in Fish Blood, and Can It Be Used Across Different Fish Species?

For this study, three cleanup methods were evaluated by QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe): two national laboratory standards, standard solid phase extraction (SPE) and Hexane wash, and a dispersive solid phase extraction (d-SPE) method (which is based on the addition of a sorbent directly into the analytical solution followed by dispersion favoring the contact between the sorbent and the analytes).⁵ Each method was measured by how well each recovered 14 different algal toxins—some that dissolve in water, some that dissolve in fat. Using statistical models, the researchers found that QuEChERS d-SPE worked about as well as the standard laboratory cleanup methods tested along with it. In fact, QuEChERS d-SPE recovered the most toxin overall—about 101%—while also being the fastest method and the second cheapest. The research team then tested QuEChERS d-SPE on blood plasma from two kinds of fish, Atlantic striped bass and blue catfish, and fine-tuned it to work well for all the toxins. Across all three fish species tested, this method recovered about 95% of the toxins on average.¹

The QuEChERS d-SPE method, according to the authors of this paper,¹ “provides a nonlethal way of sample collection to set a baseline of phycotoxin exposure in fish and illustrates that differences in sample cleanup between species may be necessary, which can help guide future monitoring, management, and public health efforts.”

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References

1. Hernandez, O. S.; Sanderson, M. P.; Latour, R. J. et al. Development of Analytical Methods for Multiple Phycotoxins in Fish Plasma. ACS Omega 2026, 11 (31), 46172-46180. DOI: 10.1021/acsomega.6c02812
2. Rattner, B. A.; Wazniak, C. E.; Lankton, J. S. et al. Review of Harmful Algal Bloom Effects on Birds with Implications for Avian Wildlife in the Chesapeake Bay Region. Harmful Algae 2022, 120, 102319 DOI: 10.1016/j.hal.2022.102319
3. Anderson, D. M.; Fensin, E.; Gobler, C. J. et al. Marine Harmful Algal Blooms (HABs) in the United States: History, Current Status and Future Trends. Harmful Algae 2021, 102, 101975. DOI: 10.1016/j.hal.2021.101975
4. Hu, Z.; Li, A.; Li, Z. et al. Editorial: The Impacts of Anthropogenic Activity and Climate Change on the Formation of Harmful Algal Blooms (HABs) and Its Ecological Consequence. Front. Mar. Sci. 2024, 11, 1397744. DOI: 10.3389/fmars.2024.1397744
5. Islas, G.; Ibarra, I. S.; Hernandez, P. et al. Dispersive Solid Phase Extraction for the Analysis of Veterinary Drugs Applied to Food Samples: A Review. Int. J. Anal. Chem. 2017, 2017, 8215271 DOI: 10.1155/2017/8215271