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A 25-kilometer swim along the coast of Saint Barthélemy. That is the distance Jade Laidin covered over six months during an internship with the Territorial Environmental Agency (ATE) to observe the coral reef within the first ten meters from the shore and assess its health. On Tuesday, September 1, the student pursuing a “Master 2 in Biodiversity, Ecology, Evolution, Marine Studies, Anthropogenic Impacts, and Assessment” at the University of Angers defended her internship report. The 41-page document is now available in its entirety on the ATE website (www.agencedelenvironnement.fr). The report concludes that 66.4% of the studied area—which spans 25.17 hectares, or two-thirds of the surveyed coastal stretch—is in a “degraded to highly degraded” state.
“A marked decline”
“Despite high coral density, the northeastern coastline is characterized by a significantly more degraded state of health than the western and southern areas, due to the combined effects of hydrodynamics and massive Sargassum washups,” the student notes. Jade Laidin’s findings were compared to an initial study conducted in 2023. The ATE notes that they highlight “a marked decline in the health of the reefs over the past three years.”
The Master’s student’s work also focused on the health of the diadem sea urchin. “As a key regulator of algae, it is significantly more abundant in the south and west than in the north,” Jade Laidin points out. A temporal comparison reveals a marked deterioration between 2023 and 2026: 57.1% of the area common to both surveys deteriorated, 34.4% remained stable, and only 8.6% improved. ” She believes this deterioration could result from “local pressures (domestic runoff, soil erosion linked to goat grazing) combined with global pressures (global warming, coral diseases, Sargassum strandings).”
Multiple Factors
In her conclusions, Jade Laidin discusses the multiple factors behind the observed degradation. “Some, such as warming waters, ocean acidification, or the frequency of Sargassum blooms, are driven by global dynamics over which local managers have no direct control,” writes the student. Others, however, such as wastewater discharges, grazing pressure from goats, and the use of anchorage areas, are locally driven and therefore potentially manageable at the local level.”
In addition to observations, analyses, and assessments, the report is enhanced by mapping. “This allows us to identify refuge areas that should be protected as a priority and sites where restoration efforts, visitor management, or enhanced monitoring would be most effective,” explains Jade Laidin.
At the same time, the scientist is careful to mention the “methodological limitations” of her work. “Since the assessment protocol relies in part on the observer’s visual judgment, a certain degree of subjectivity remains inevitable,” she writes, adding the possibility “that the overall health of the reefs may be better in deeper areas or those farther from the coast.” In any case, the quality of her work has been praised by the Regional Environmental Agency.
In fact, the Agency emphasizes that the student’s work will be included in the Ifrecor 2020–2025 report.
A Nature Outing to Petit-Cul-de-Sac with the ATE
Explore Petit-Cul-de-Sac Beach, discover its ecosystem and vegetation, and observe sea turtle nesting sites. Here is the itinerary for the nature outing organized by the Territorial Environmental Agency (ATE) on Wednesday, September 16.
The event, scheduled for 5:00 p.m. at the entrance to Petit-Cul-de-Sac Beach, is open to adults and children ages nine and older who are accompanied by an adult.
Those wishing to take part in this short nature excursion—organized as part of the upcoming 30th anniversary of the Nicole Aussedat Nature Reserve—can register by contacting the Agency via email (contact@agencedelenvironnement.fr).
The outing is free and open to everyone.
