The latest report by GEN-GOB highlights a critical decline in the Posidonia oceanica meadows of Ibiza, with 17 out of 18 sampling stations showing unfavorable conditions. The increase in dead seagrass is alarming, prompting concerns for the marine ecosystem’s health.
Significant Findings from the 2025 GEN-GOB Report
Conducted as part of the Xarxa Posidonia initiative by the Government of the Balearic Islands, this report sheds light on alarming statistics regarding Ibiza’s seagrass. The sampling points analyzed were predominantly located in the following areas:
- Talamanca
- Cala Roja
- Cala Vedella
- Sa Conillera
- Cala d’Hort
- Cala Llentrisca
- Porroig
- The Xanga
Critical Areas of Concern
The study identifies Talamanca as critically affected, with an average of 50% dead seagrass. Variability ranged from 30% to 70%, significantly indicating stress on the ecosystem. Additionally, Cala Vedella shows a concerning downward trend over recent years, reinforcing the report’s findings about continuous degradation.
Contributing Factors to Deterioration
The report attributes the decline of Posidonia meadows to several human-induced factors:
- Anchoring of boats on the seabed
- Brine discharge from desalination plants
- Submarine outfalls
Furthermore, marine heatwaves exacerbate these problems. Temperature sensors reveal water temperatures exceeding 28 degrees Celsius for weeks during summer, stressing the seagrass and affecting its vitality.
Positive Indicators in Certain Areas
In contrast to the general decline, Cala Roja displayed the most favorable metrics, exhibiting stable coverage of living Posidonia. This resilience is attributed to its lower exposure to anthropogenic impacts.
Monitoring and Future Efforts
Since 2019, GEN-GOB has been actively monitoring these meadows. The ongoing program utilizes non-invasive techniques for assessing the extent and density of the Posidonia coverage and identifying degraded areas and invasive species. Field surveys are scheduled throughout the year to continue tracking the health of these vital habitats.
The Importance of Posidonia Oceanica
Posidonia oceanica is crucial for marine biodiversity across the Pitiusas. These meadows serve essential roles, including carbon sequestration, oxygen production, stabilization of seabeds, and improvement of water quality. The meadow in Es Freus, noted for its exceptional ecological value, is recognized as part of UNESCO’s World Heritage designation for Ibiza.
The findings from the 2025 report underscore the urgent need for enhanced protective measures and a collective commitment to reducing human pressures on this vital Mediterranean ecosystem.
