On 18-19 September in Vienna (Austria), the IAEA will hold its annual Scientific Forum. The theme for this year is Nuclear Technology for Climate: Mitigation, Monitoring and Adaptation. One of the topics discussed will be addressing global change impacts on the marine environment by using nuclear techniques.
The geographical range and intensity of harmful algal blooms (HABs) have been increasing over the last decade, a change linked to global warming. An increasing number of countries are turning to nuclear science in order to identify and measure these blooms and the biotoxins they produce, and then — armed with the data — establish appropriate policies and countermeasures to control their impact more effectively.
Each year, HABs are responsible for the poisoning of thousands of people worldwide through consumption of contaminated seafood and inhalation of toxins. “Faced with the apparent increase in frequency, geographical distribution and intensity of such blooms, addressing them on a global scale has become urgent,” said Marie-Yasmine Dechraoui Bottein, a research scientist at the IAEA Environment Laboratories in Monaco.
Microscopic algae at the base of the marine food chain provide nutrients for marine organisms and are responsible for producing more than half the earth’s oxygen supply. However, factors such as the surface water temperature, the circulation of wind and water, the natural movement of nutrient-rich waters towards the surface or the accumulation of agricultural run-off into the sea can trigger algal blooms, which can sometimes include toxic species.
Although strategies to control the impact of planktonic toxic HABs, which float in the water, are well defined, there remain gaps in the scientific understanding of those on the ocean floor, known as benthic species. Environmental changes linked to climate change could make matters worse in tropical areas, as dead coral reefs constitute good habitats for macroalgae, said Clemence Gatti, a research scientist at the Louis Malardé Institute in French Polynesia. With the increasing number of corals dying, a proliferation in benthic HABs and associated health risks are likely. Likewise, with temperatures increasing globally, tropical toxic species thrive in expanded areas of the subtropics and temperate seas and oceans.
The impact of foodborne illnesses is of the same magnitude as illnesses like malaria and tuberculosis. More work is needed to gather data and develop methodologies so States can address this issue.
