Climate change: A pointer to increased small-scale fisher drowning deaths

of unintentional injury mortality, accounting for 7% of the world’s injury related deaths [1]. Around 90% of unintentional drowning deaths occur in low- and middle-income countries, with the highest estimated death rates occurring in Africa [1, 2]. In some African communities located near water, drowning death rates exceed those of well-known public health threats, such as malaria, HIV, or tuberculosis [3]. However, unlike these well-known threats, drowning has received little attention in academia, practice, and policy [2, 4], particularly in low-income countries [5]. While drowning mortality is typically highest in children [6, 7],occupational groups such as fishers are often at extremely high risk as well. Climate change is projected to increase the frequency and intensity of extreme weather events [8], with East Africa particularly vulnerable to thunderstorms [9]. While little is known about how climate-related increases in storms are already altering the incidence of drowning deaths among fishers, stormy weather conditions are an established drowning risk factors for fishers, with significant reported cases from East Africa [2, 3, 10, 11]. For example, a recent study in Lake Victoria, Africa’s largest lake, indicates an estimated 1,500 drowning deaths occur annually, of which two-thirds (1,000) are estimated to be weather related [12]. These weather shifts are therefore predicted to compound the risk of drowning for small-scale fishers in low-income countries [13, 14], who already face a range of occupational drowning risk fac-

tors: lack or inadequacy of safe boats, little life-saving equipment (e.g., life preservers), and weak safety regulation enforcement [2, 3, 10, 11]. Information on the role of stormy weather conditions, alongside other risk factors, is thus needed to shed light on the potential contribu- tion of climate change to mortality in small-scale fishing communities and proactively design climate-related strategies (e.g., improved storm warning systems) to mitigate risks. Lake Victoria has high fishing pressure from approximately 200,000 fishers operating on the lake [15] and is a hotspot for severe thunderstorms [16, 17] and therefore, claimed to be among the most dangerous stretches of water in the world [13, 18]. Thunderstorms over Lake Victoria are predicted to become more intense, including the intensity of precipitation and wind gusts, and up to 10 times more frequent by the end of the century [13, 14]. In 2018, on the Tanzanian side of Lake Victoria, fisher drowning death rates were estimated at a staggering 1.4%, a rate that exceeds that of even other high-risk groups (e.g., children, boat passengers) [3]. Compounding climatic effects is a change of fishing pattern over the latest few decades. As Nile perch (Lates niloticus), a key commercial fish species, has declined [19], fishers have increasingly turned to a sardine-like species omena (Rastrineobola argentea) [20]. Omena are fished far offshore, and at night when lights are used to illuminate their food sources and thereby attract fish [21]. However, thunderstorms are most likely to occur at night [13], and

visibility is limited, increasing the risk of collision and poor navigation, all of which make fish- ers more vulnerable to drowning. Further, as fishers are often key providers within their households, pressure to fish, even in poor weather conditions to bring in needed income, can be high and drowning deaths can also have far-reaching, negative socio-economic conse- quences for households [3]. The interactions between climate change, vulnerability, pressure to fish, and fish declines create a negative feedback loop or socio-ecological trap that exacer- bates fishers’ drowning death risks. In the Lake Victoria region, fishing provides substantial income and health benefits locally in context where vulnerability to food insecurity is widespread [22, 23]. Fishing is interrelated with the health and well-being of local fishers who alter fishing practices in response to illness [22]. Fishers and traders on the shores of Lake Victoria have faced a longstanding risk of HIV [24, 25] with transactional sexual exchanges exacerbating risks [20, 26, 27]. Today, HIV preva- lence within fishing communities along the shores of Lake Victoria remains some of the high- est in the world [28]. This omnipresent health risk has been described as intertwined within a PLOS ONE Climate change and small-scale fisher drowning deaths PLOS ONE | https://doi.org/10.1371/journal.pone.0302397 May 22, 2024 2 / 16 2009658) received by KJF. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.