Marine heat waves are becoming increasingly frequent, longer-lasting, and more intense as the planet warms. Beyond the effects on marine life, these phenomena of abnormally high sea temperatures may also be adversely affecting the health of children living in coastal communities.
The conclusion comes from a study by the University of North Carolina at Chapel Hill and Pennsylvania State University (United States of America), which analyzed health data for children and women from more than 9,800 coastal zones across 36 low- and middle-income countries. Using these data, they cross-referenced information on global sea surface temperatures.
Subsequently, the researchers identified marine heatwaves that occurred in waters near the communities in the months and years before the health data were collected. The team then applied statistical techniques to reveal the relationship between exposure to marine heatwaves and health outcomes.
They found that increases in the number of marine heatwaves raised the probability of infant mortality by 5.4%, of children being too underweight for their height by 6.5%, and of being too short for their age by 8.8%.
The researchers suggest that these impacts may be due to fish being an important source of protein and micronutrients for many coastal communities, and that marine heatwaves may affect the amount of fish available locally and cause episodes of mass mortality that deplete stocks, as well as their nutritional quality.
“Such disruptions can have direct impacts on food supply and can also have secondary effects, affecting fishermen’s incomes and food prices for consumers,” explains Brian Thiede, of Pennsylvania State University and co-author of the study published in the journal ‘PNAS.’
“These factors can influence families’ ability to buy food or to have the financial resources needed to access other essential services, such as healthcare,” he adds.
According to this work, the impacts of marine heatwaves on children’s health in coastal communities are most significant in countries dependent on artisanal fishing (as opposed to industrial fishing) and in urban areas.
The researchers point out that the results make clear that climate change is impacting many of the Earth’s systems that are vital to human health and survival, including for coastal communities that depend on the ocean for their food and livelihoods.
“Coastal populations face climate-related risks unique to their environment and livelihoods,” adds Thiede.
Since human populations globally tend to concentrate in coastal environments, or around them, the researchers suggest implementing measures to help these communities most exposed to the effects of marine heatwaves obtain the nutrition and support needed to mitigate these impacts on their health.
