#South Korea #Incheon #Incheon University #Harmful Algal Blooms #Prorocentrum lima

Researchers Uncover Toxin Risks in Algal Blooms

Researchers from Incheon National University have brought critical insights into the risks posed by harmful algal blooms (HABs) during periods of nutrient starvation. Their study, which highlighted the increased toxin production in the dinoflagellate _Prorocentrum lima_, reveals significant implications for seafood safety and coastal ecosystems.

Algal Blooms and Their Dangers

Harmful algal blooms are a growing concern globally, threatening both marine environments and public health due to their capacity to produce dangerous toxins. One particularly concerning species, _Prorocentrum lima_, is known for producing toxins such as okadaic acid and dinophysistoxin 1, which can cause severe gastrointestinal illnesses in humans who consume contaminated seafood.

Traditionally, research has focused on short-term responses of these algae to nutrient changes. However, the current study delves into the effects of prolonged nutrient depletion, which had not been extensively analyzed.

The Study's Findings

Led by Professor Jang K. Kim, the researchers observed _P. lima_ cultures under nutrient-rich conditions until they reached a stationary growth phase. Subsequently, the nutrient supply was halted, and the cultures were monitored over a thirty-day period, focusing on changes in cell density, nutrient uptake, photosynthesis, and toxin levels.

The results were alarming. Although the overall cell numbers remained stable, the toxin concentration per cell rose drastically. Researchers found that, surprisingly, nutrient starvation led to an over threefold increase in okadaic acid levels and more than double the concentrations of dinophysistoxin 1, which were significantly above the levels reported in previous studies.

Implications for Seafood Safety

This unexpected rise in toxin levels during nutrient depletion suggests that even when algal growth seems stable, the potential danger to seafood safety can be increasing undetected. The researchers proposed that this disconnect between algal abundance and toxicity presents new challenges for predicting hazardous conditions. As environments experience nutrient scarcity, the possibility for heightened toxicity in alga becomes an unrecognized risk for consumers of affected seafood.

Prof. Kim noted, "Our work aims to enhance the understanding of the dynamics of algal growth and toxin production during nutrient-poor spells. This knowledge can be pivotal for improving the monitoring and management of DSP-related harmful algal blooms."

Conclusion

The findings from Incheon National University pave the way for a deeper understanding of how nutrient dynamics affect harmful algal blooms. By shedding light on the hidden risks linked to nutrient depletion, these researchers emphasize the need for advanced methods in monitoring algal blooms and ensuring public health safety. This study not only adds to the body of knowledge on HABs but also plays an essential role in developing strategies to mitigate their risks.

Reference

• - Kim, J.K., et al. (2025). Effects of nutrient depletion duration on growth, photosynthesis and toxins (OA and DTX) in the dinoflagellate _Prorocentrum lima_. Harmful Algae, 149, DOI: 10.1016/j.hal.2025.102932.