The Aquarium La Rochelle has founded the Centre d'Etudes et de Soins pour les Tortues Marines to welcome, care for and study these animals found in distress on the English Channel and Atlantic coast of France.

One of their patients, a juvenile loggerhead turtle (Caretta caretta) nicknamed 'Neige', was rescued on the Landes coasts at the end of 2022, and released in June 2023 with an Argos telemetry tag. On the first leg of its journey, Neige headed north, then rounded Brittany before reaching the English Channel. There, it began to zigzag, with a distinctive period of about 12 hours. In the North Atlantic, tides are semi-diurnal, and the Mont Saint-Michel Bay is a site well-known for its particularly large tidal amplitudes.

When comparing the turtle's zigzagging path with FES model tidal currents, one can see that they are in phase, so most probably Neige was carried by the strong tidal currents of the English Channel. Whether or not the turtle realized its trajectory, or even was able to take advantage of these currents, would be a topic for a dedicated scientific study. This is possible, unlike the examples we showed earlier, with drifting buoys!

See also:

• Image of the Month, Sept 2021: A buoy spiraling at Burdwood bank
• Image of the Month, Feb 2017: Tidal currents make a buoy's path spiral
• Applications: Biology

Other web sites on this topic:

• Argonautica educational project and data access (in English)
• CESTM (Centre d’Études et de Soins pour les Tortues Marines):