A scientist collects samples to test for algal blooms in the ocean that can make people sick, harm ocean life and cost millions of dollars in lost seafood revenues. Photo: IAEA

Scientists at the International Atomic Energy Agency (IAEA) are working with researchers in Cuba to detect and measure biotoxins in ocean organisms and develop monitoring and reference tools that will help identify such outbreaks worldwide.

“With a better understanding of how harmful algal blooms behave and how their toxins enter the food chain, it will be easier for countries to monitor toxins and control the consumption of contaminated seafood,” said Marie-Yasmine Dechraoui-Bottein, a research scientist at the IAEA leading this collaborative project with the Centre de Estudios Ambiantales de Cienfuegos (CEAC) in Cuba. “Harmful algal blooms have a particularly big impact on small island states that rely heavily on their fisheries and tourism.”

In Cuba, the fishing and sale of thirteen fish species including groupers, snappers and jacks have been prohibited year-round since 1996 due to a high risk of ciguatera fish poisoning – due to toxic algae. It is only recently that Cuban scientists, with the help of the IAEA, acquired the capability to measure ciguatera toxins in seawater and in fish and shellfish using a nuclear technique called radioligand receptor binding assay (RBA).

This method of measurement is based on the specific interaction between the toxins and the receptor they bind (pharmacological target), in which a radiolabeled toxin competes for a limited number of receptor binding sites with the toxin in the sample being analyzed, allowing quantification of the toxicity of the sample.

During the course of a recent field mission in Cuba, a team of IAEA scientists and local fishermen collected fish and algae samples at different depths to study the distribution of toxic harmful algal bloom species.

Once the samples have been processed in Cuba, they will be tested at the IAEA’s marine laboratory in Monaco. As a result, the IAEA will develop the first-ever reference material for ciguatoxin monitoring worldwide.

Such reference materials are critical for national authorities in managing marine environments and adhering to fish trade regulations. While the exact number of people affected and economic losses are difficult to estimate, the impacts of harmful algal blooms are nevertheless considerable.

“With these data and reference materials, we can refine how we monitor toxins to help minimize their impact,” said Dr. Dechraoui-Bottein. “It is important to keep in mind that ciguatera fish poisoning remains the most common non-bacterial seafood intoxication worldwide.”

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