Psychological effects of a toxic bloom – a lesson from Australia

A year ago, in Wodne Sprawy we wrote about a toxic bloom off the coast of southern Australia caused by the dinoflagellate Karenia mikimotoi. It was a red tide typical of warm waters such as the Great Australian Bight. The bloom began in March, at the end of the local summer. It proved deadly mainly for fish and octopuses. In comparison, surfers and even people walking along the beach who inhaled aerosol containing the toxins suffered less. In their case poisoning manifested as watery eyes, sore throat or coughing. In March alone about one hundred people sought medical help.

Summer passed, yet the bloom continued until July. Its impact on health attracted the interest not only of physicians but also of psychoecologists led by Dr Brianna Le Busque from the University of Adelaide (as well as the Centre for Marine Socioecology at the University of Tasmania). For several years psychology has distinguished the concept of eco-anxiety, and one of the tools used to study it is a scale developed by Teaghan Hogg, also an Australian psychologist. The researchers managed to reach more than 600 adults (aged 18 to 88) who had visited the beach during the bloom. Of these, 568 completed the Hogg questionnaire in a way suitable for statistical analysis. The results of the study were published a few days ago in the Journal of Environmental Psychology.

Mental health also suffers as a result of blooms

The principle of the questionnaire was to select recurring effects rather than only single incidents. The largest group of respondents, nearly 70 percent, reported rumination, meaning intrusive recurring thoughts related to the bloom. Slightly fewer admitted to a sense of helplessness when confronted with an ecological disaster. A feeling of fear or anxiety as such was reported by more than half of the participants. Fewer, though still 20 percent, experienced behavioral disturbances that made it difficult to sleep at night or concentrate at work.

Most respondents admitted that observing the bloom and its consequences affected their lives. The study concerned a recently experienced situation, so the durability of this influence cannot be assessed. Nearly half of those surveyed abandoned their previous ocean-related activities. It should be remembered that the questions were asked to people who had previously used the beach for various purposes, mainly recreational ones – from walking and fishing to swimming and surfing. Meanwhile, ways of spending time that had previously relaxed them became a source of stress. Comparisons with grief also appeared. A small group eliminated seafood from their diet. Some respondents also reported problems affecting their pets.

One quarter of respondents experienced direct physical health effects of the bloom. These included irritation of the respiratory tract and coughing, sometimes nausea. This effect is probably temporary, whereas the persistence of psychological impacts is harder to estimate. In psychology, and even psychiatry, studies on the therapeutic effects of nature are well known. Most of them concern the presence of forests, urban greenery and trees, as well as birdwatching, but an analogy can also be found with contact with water. Toxic blooms, regardless of whether they are natural or anthropogenic, undermine the trust that people have developed toward nature.

Did the Oder bloom trigger eco-anxiety?

Research on eco-anxiety is also conducted in Poland. So far the greatest attention has been devoted to the impact of climate change. This is understandable given the all-encompassing influence of this phenomenon on humanity. However, I have not managed to find evidence of similar studies related to toxic blooms, which may be surprising in the context of the Oder disaster in 2022. The topic of that event itself is not limited to broadly understood water management and the environment. It appears in numerous initiatives that can be described as anthropological, yet the voice of psychologists does not stand out among them. And it is hard to believe that the many members of the “Oder tribe” did not experience eco-anxiety.

Climate change favors blooms, including toxic ones, so the role of psychologists exploring this issue is likely to grow. Le Busque notes that blooms are recognized as a problem for the economy and nature, but it is also important to remember the costs borne by people: interference with daily routines, undermining the sense of attachment to places, and disrupting relationships with nature.

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Source:

Scientific publication: Brianna Le Busque, Laura J. Falkenberg, Craig Williams, Carla Litchfield. 2026 Psychological toll of a marine environmental crisis Journal of Environmental Psychology, 110, 102964 https://doi.org/10.1016/j.jenvp.2026.102964