Article Date: March, 2026
The report, “Biodiversity at the WindFloat Atlantic Project – Floating Offshore Wind Farm, Viana do Castelo, Portugal,” is a non-technical summary of biodiversity monitoring at the 25 MW WindFloat Atlantic floating offshore wind farm, located about 18 km off northern Portugal in water depths of roughly 95-100 meters. The project has three floating wind systems and entered operation in September 2020.
The study combines required environmental monitoring with additional scientific work to understand how the floating wind farm affects marine biodiversity. It examined water quality, underwater noise, plankton, fish, octopus, invertebrates, marine mammals, seabirds, bats, and biological growth on the platforms. Monitoring included baseline surveys before installation and operational-phase surveys through April 2025.
The main conclusion is that the wind farm has not disrupted overall ecosystem functioning. Natural seasonal and year-to-year changes were the main drivers of biological variation, while the project area showed signs of local ecological benefits, especially for fish and invertebrates. Fish abundance and biomass were consistently higher inside the WindFloat Atlantic area, likely due to a combination of fishing exclusion, habitat protection, and reef effects from the floating structures.
The report found no significant negative effects on plankton, while higher-trophic groups such as fish, octopus, and some invertebrates showed positive trends in the wind farm area. It recorded 52 fish species, including commercially important and conservation-relevant species, and found that platform surfaces were colonized by marine life such as kelp, barnacles, mussels, sea stars, and anemones.
For wildlife, the study recorded five marine mammal species, 33 bird species, and three bat species. Marine mammals, especially common dolphins, showed increased activity during operation, while bats were detected only sporadically and did not appear to use the turbines as shelter. For seabirds, the area appears mainly to function as a migration corridor; no collision mortality was recorded, although models identified some gulls and northern gannets as higher-risk species.
The report also notes areas that require continued monitoring, especially the presence of non-native species on the platforms. Most remained low in abundance, but wakame algae increased over the last two monitoring years. Overall, the findings suggest that floating offshore wind farms can coexist with marine biodiversity and may create local refuge and reef benefits, but long-term monitoring remains important as the technology scales up.
Source: Windfloat Atlantic