Mauve Stinger Logbook Wales 2025

24/7
Monitoring Coverage
Wales
​Coastal Coverage
2025
​Research Project
Mauve Stinger Logbook Wales 2025
Project Status Completed

Data collection closed on 31 December 2025. No further observations are being accepted.
The dataset is now locked and preserved as a permanent scientific record of Pelagia noctiluca in Welsh waters.

About the Mauve Stinger Project

The Mauve Stinger (Pelagia noctiluca) is one of the most common stinging jellyfish in European waters. Our citizen science project tracks bloom events across the Welsh coast to protect communities and advance marine research.

  • Record Blooms

    Track jellyfish bloom events across Welsh coastal waters with precise location data.

  • Public Engagement

    Engage communities in marine conservation through accessible citizen science participation.

  • Safety Guidance

    Provide essential safety information for communities and coastal visitors.

  • Scientific Research

    Share data with researchers to better understand bloom patterns and marine ecosystems.

What to Look For

  • Bell Shape: Translucent with purple-pink coloration as adult, and brown-orange coloration as juvenile
  • Size: Bell diameter 3-12cm (1.2-4.7 inches)
  • Tentacles: Four long, trailing tentacles
  • Behavior: Often found in groups (blooms)

⚠️ Safety First ​

  • Do not touch jellyfish, even if they appear dead
  • Maintain safe distance when photographing
  • Wear protective footwear on beaches
  • Report to lifeguards if swimming areas are affected

About Pelagia noctiluca

Pelagia noctiluca is a common scyphozoan jellyfish in temperate European waters. It has a translucent bell often showing mauve or purple pigmentation and short marginal tentacles. The species is capable of forming large swarms that may wash ashore, affecting recreation and small-scale fisheries.

The tentacles of the mauve stinger (Pelagia noctiluca) can extend to more than 2 meters when fully outstretched and actively feeding.
​
Everyone needs to know where mauve stingers (Pelagia noctiluca) have been observed, as this information helps build a clearer picture of their seasonal patterns, abundance, and potential risks to swimmers, fishers, and coastal communities. By reporting your sightings, you are directly contributing to citizen science and helping researchers, conservationists, and decision-makers better understand the distribution of this species.

We encourage you to share your observations with us so we can maintain these records as open data. This means that the information will be freely accessible and can be used by educators for teaching, by the media for raising awareness, by organizations for planning coastal activities, and by the public to stay informed and safe.
Every report matters, whether it is a single jellyfish or a large bloom. Even simple details such as date, location, water conditions, and abundance can provide valuable insights. Over time, these collective contributions form a powerful resource that supports science, conservation, and community awareness. 

​At the end of our page, you can submit your observation.

During the summer and autumn months, it is when one needs to be cautious, when the sea temperature rises and currents concentrate plankton.

Mauve Stinger Safety Guidelines

Mauve stingers can deliver painful stings even when washed up on beaches.
Follow these essential safety guidelines to protect yourself and your family.
⚠️ Important Warning

Mauve stingers remain dangerous even after death. Their nematocysts (stinging cells) can remain active for hours on beached jellyfish. Never touch jellyfish with bare hands, even if they appear dead.

□️ Prevention Tips

  • Wear protective clothing: Full-body wetsuit, rash guard, or protective swimwear
  • Use closed footwear: Water shoes or boots when walking on beaches
  • Check beach conditions: Look for warning signs or ask lifeguards
  • Avoid swimming during blooms: Wait for all-clear from authorities
  • Stay alert in water: Look out for jellyfish while swimming

❤️ First Aid Treatment

Immediate Steps:

  1. Remove from water safely
  2. Rinse the affected area with seawater. Do not use fresh water, ammonia, or vinegar
  3. Do not rub the affected area
  4. Remove visible tentacles with tweezers, plastic card, or stick
  5. Apply a baking soda slurry (approximately 50% baking soda, mixed with seawater)

Pain Relief:

  • Apply hydrocortisone after seawater and baking soda mix treatment (to help reduce local inflammation and itching)
  • Antihistamines for allergic reactions

999

Severe reactions, difficulty breathing

NHS 111

111

Non-urgent medical advice

Coastguard

999

Marine emergencies

Data & Sightings Map

View jellyfish sightings across Welsh waters and explore our comprehensive data collection
   Data Log​
    Complete database of sighting reports and scientific data
   Sightings Map​
    Interactive map of all reported mauve stinger locations