Staying safe in a changing ocean
Author: Kerri Hall, Communications Manager, BlueAdapt
Understanding waterborne infections
Every summer, millions of people swim in coastal waters, but how many stop to think about what’s in them? Before we launch our new facts series, we explain what coastal pathogens are, where they lurk, how they impact our health, and how to stay safe.
What are coastal pathogens?
Coastal pathogens are harmful microorganisms, including bacteria, viruses, and parasites, found in coastal and river waters. They can cause infections ranging from stomach upsets and skin rashes, in some cases, more serious illness. Understanding them is the first step to staying safe.
Why are coastal pathogens a growing concern?
- Warmer seas = faster pathogen growth: Rising sea temperatures enable pathogens to multiply quickly. This increases infection risks for swimmers, seafood consumers and coastal communities – including infections that antibiotics can’t treat.
- Extreme weather is amplifying exposure: Heatwaves, heavy rainfall, and flooding can increase pathogen transmission and spread antimicrobial‑resistant (AMR) bacteria.
- Pollution creates conditions where pathogens can linger: Wastewater and pollution enable viruses and bacteria to survive longer in coastal and river waters.
How can you stay safe in coastal waters?
While BlueAdapt focuses on research and solutions, there are practical steps you can take to minimise the risk of exposure to harmful infections. These actions not only support personal safety, but they also help to improve overall public health and boost coastal resilience.
1️⃣ Pay attention to local water quality alerts
BlueAdapt is exploring how early‑warning systems and smartphone alerts can improve how warnings are delivered. Staying informed (especially after heavy rainfall or pollution leaks) reduces risks.
2️⃣ Avoid swimming after storms or flooding
Extreme weather increases the level of contaminants washed into the sea, from sewage discharge and from off the land, elevating the risk to human health. It is recommended to leave it at least 48-72 hours after heavy rain before entering the water.
3️⃣ Choose designated bathing sites when possible
Europe has over 20,000 monitored bathing water sites, where pollution and pathogen levels are regularly assessed. These locations provide safer swimming options. This map shows tested bathing waters in Europe. For the UK, you can use the Safer Seas and Rivers App. For Ireland, check www.beaches.ie.
4️⃣ Reduce contact with water near known pollution sources
Rivers impacted by storm runoff and wastewater discharges allow viruses to persist for longer, making nearby coastal waters riskier to bath in.
5️⃣ Clean up after enjoying the water
Showering after swimming, avoiding swallowing water, and cleaning cuts promptly all reduce the risk of exposure to harmful microorganisms.
6️⃣ Stay informed about antimicrobial resistance risks
Swimming in contaminated water can expose you to antibiotic-resistant bacteria like E. coli, Enterococcus, and Staphylococcus aureus (MRSA). Research shows that coastal water users can be more likely to carry antimicrobial-resistant (AMR) bacteria in their gut, which has likely entered the water through agricultural runoff and sewage.
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Over the next 12 weeks, we’ll share short weekly facts on climate change, pollution, coastal pathogens and what they mean for coastal communities.
As a pan-European project, BlueAdapt is collecting, analysing and translating evidence to help experts develop protective policies, health communications and more effective early‑warning systems. Together we hope that communities can continue to live, work and enjoy the coast safely.
