What is Meduseo?
Meduseo is above all an information tool, an aid to save time and favor the right beach with complete peace of mind. Arriving on a beach and seeing jellyfish in the water is annoying. The ultimate goal of Meduseo is to provide a jellyfish weather service.
A Unique Scientific Database
Historically, Meduseo relied on indirect data extraction. Today, the model has radically evolved: 90% of the signals now come directly from user reports on the site and the app.
As of 04/16/2026, nearly 90,000 reports have been collected over the last 4 years. This colossal amount of data isn't just for beach forecasts: we collaborate scientifically with the MARBEC team at the University of Montpellier to analyze and exploit this data.
The Power of the Crowd
The accuracy of Meduseo now relies on your engagement. By reporting a jellyfish, you are participating in a global participatory science program.
You can now make GPS reports anywhere in the world, upload a photo of your observation and describe the jellyfish (color, size, species). These details are crucial for our scientific partners to better understand the life cycles and movements of these organisms.
Please note that no personal information or private data is collected or stored.
What about reliability?
With 90% direct validated reports, reliability has never been higher. To see how we verified the reliability of our historical model, you can check out our dedicated page here.
Coverage
France, Italy, Spain, Australia, New Zealand... We provide information on jellyfish presence for all these countries, and the list continues to grow.
You too can participate!
You can report the presence of jellyfish via the Android app, iPhone app, or the website. Send your GPS location, describe what you saw, and inform the community!
Become a Certified Contributor
The certified contributor status ensures that the information comes from a reliable source. While we actively manage the data, false reports can occasionally slip through. It is therefore important to have trusted individuals (swimmers, organizations, associations, or local authorities) to confirm the data and help the community choose their swimming spots safely.
How to become one? Simply create an account specifying your location and the context of your observations (swimming, water sports, surveillance, or leisure). This status is not just for professionals! Once validated, you will have access to a Meduseo account that allows you to submit certified reports. To learn more, visit this page.
AI and Forecasts
Artificial Intelligence helps us analyze the submitted data to identify species automatically. This approach will allow us to predict the appearance of jellyfish at D+1 in the future.
Explorer: Analytics & Probabilities
Thanks to this massive database, you can now use our Explorer tool. It displays a calendar showing the probability of presence of jellyfish for a given city, based on the average of past observations for each day of the year.
Additionally, for cities with sufficient data, you will find a detailed environmental analysis highlighting the impact of meteorological variable differences between days with and without jellyfish.
Who created this tool?
My name is Jérémy Deverdun, I am a research engineer. In my spare time, I develop and improve Meduseo to make it available to as many people as possible.
The tool is completely free. Do not hesitate to contact me: contact@meduseo.com.
Thank you ...
To all contributors, the University of Montpellier (MARBEC), and the media for their support.