The ocean around the Canary Islands is experiencing exceptionally high water temperatures in 2026. Data from the observation system IEOOS of the Instituto Español de Oceanografía show that the Demarcación Marina Canaria has recorded values mostly above historical averages since mid-June. On 29 September 2026 the mean daily water temperature was 25,54 °C; only the 2023 peak of 25.76 °C was higher in the series. The annual peak generally occurs between August and October.
Experts attribute the current extremes to two factors acting together: the current El Niño, which warms sea surfaces over large areas, and the ongoing global warming trend. IEOOS time series show that averages in the 2020s are significantly higher than in previous decades. The European climate service Copernicus also reported exceptionally high global sea-surface temperatures in September 2026, supporting the view that the heat anomaly is widespread.
Research groups on the islands clearly identify the ecological risks. Higher surface temperatures alter stratification and mixing, which can affect oxygen levels and nutrient availability. Observed changes include shifts in fish populations, a rise in the occurrence of heat-loving invasive species, and signs of stress in larval stages and benthic communities. Laboratory studies of the starfish species Coscinasterias tenuispina report that persistently very high temperatures can lead to physiological collapse. Coastal seagrass and algal beds, which serve as nurseries, are considered particularly vulnerable.
For the region, this has economic as well as biological consequences. Coastal fisheries and downstream value chains must prepare for changing species distributions and possible fluctuations in yields. Authorities and scientists therefore advocate close, systematic monitoring, prompt analysis of IEOOS measurement series and close coordination with the regional administration to prepare adaptation measures. These include more flexible stock management, stronger monitoring of invasive species and protection of particularly vulnerable habitats.
The measurements and assessments cited refer to publicly documented IEOOS data series and current analyses by the Copernicus service. Statements about long-term changes in populations remain provisional; they depend on future weather, the intensity of El Niño and local marine conditions, and are subject to ongoing review.
Editor: Andreas M. Brucker (Article created with AI assistance).