French scientist Antoine Collin has recently been in French Polynesia on a six-day field campaign to test and validate the capabilities of the Sentinel-2 satellite to monitor coral bleaching.

While the field work may now be over, the task of analysing the data lays ahead. This video, sent from the field, takes a look back at the group’s time spent surveying the waters around Fatu Huku.

Fatu Huku Island in French Polynesia was chosen as the survey site because of the presence of developed coral reefs and it is an area water temperatures are high as a result of the current El Niño event.

Antoine explains, “Unlike other Marquesas islands, Fatu Huku exhibits a significant spatial coherence of the coral reefs. During our survey, we systematically recorded water temperature exceeding 30°C.”

This means that hard corals are very likely to expel their symbiotic algae, the zooxanthellae. In addition to losing their vivid colours, the health of hard corals suffers. Unfortunately, Antoine and the team could see that this had happened.

In this next video we see Antoine summing up the field campaign, which included some pretty bad weather and sea condition, before he headed off back to Europe to start analysing the wealth of data they collected.