Scientists monitored three floating wind turbines off Portugal for eight years, and 270 species showed up around them—including more octopuses, sole, and rays

Three floating wind turbines stand in the Atlantic some 12 miles off the coast of northern Portugal, with marine life swimming beneath.

Offshore wind is frequently described as a compromise between clean energy and disturbance of the ocean. But after eight years of monitoring around WindFloat Atlantic, there was something more complex.

Increase in abundance was observed in some animal groups within the project area compared to nearby comparison areas. The results were released in April 2026, providing additional data for the offshore wind debate.

The project also observed an increase in dolphin and porpoise activity during operations, but the area is already used for dolphin migration.

What animals were actually working at this working energy site?

The transition from three floating turbines to a long running field study

WindFloat Atlantic is located off Viana do Castelo and operates with three semi-submersible floating platforms.

This 25-MW project started to feed electricity into Portugal’s electricity grid in 2020. Environmental monitoring started earlier and continued through construction and operation.

That long history provided researchers with something unusual in the offshore energy world. They were able to compare the conditions before the turbines were installed with conditions after a number of years operating.

The work encompassed various levels of the ecosystem, ranging from plankton to marine mammals and seabirds.

Fish, bottom-associated invertebrates, bats, and other wildlife were also examined around the project and nearby control areas.

The turbines are not fixed on foundations driven into shallow sea bed. Rather, each one floats and is held in place with mooring systems.

Those structures provide hard substrate and cover in open water below the surface.

The surrounding safety zone also limits normal navigation and fishing activity close to the turbines.

All of those changes combined provided a valuable indicator of the compatibility of energy infrastructure and marine communities.

The biggest shift occurred with larger animals

The monitoring was not consistent across all levels of the food web.

During the study period, Ocean Winds found no significant negative impacts on phytoplankton or zooplankton.

The researchers observed greater differences between the wind farm and the surrounding waters at higher levels of the ecosystem.

The abundance and biomass of octopus increased in the project area. There was also an increase in the abundance of some fish groups.

Researchers specifically highlighted sole and elasmobranchs, the group containing sharks and rays.

The project also observed an increase in dolphin and porpoise activity during operations, but the area is already used for dolphin migration.

These patterns were important because the turbines were not just attracting one conspicuous species.

Rather, monitoring indicated that multiple species of animals were utilizing the protected area surrounding the floating structures.

The overall ecosystem was still more strongly influenced by natural seasonal and year-to-year variations.

Despite this, the project area had local variations which were correlated with two interacting features.

One decreased fishing pressure. The other altered the physical habitat in the water.

The 270 species constituted a much wider community

During the monitoring program, researchers spotted over 270 species around WindFloat Atlantic.

Of those, 52 fish species, five marine mammal species, 33 bird species and three bat species were counted.

Mammals recorded included common dolphins.

The fish community consisted of commercially important fish species and sharks and rays which increased in abundance within the project area.

Another big element of the story was the octopus. Their abundance and biomass were also higher near the turbines.

The reason for spinning blades was not to make the ocean better.

Instead, researchers cited a fishing exclusion effect and an artificial reef effect around submerged structures.

How to keep the local benefit within limits

The exclusion zone helps to protect animals from regular fishing and provides a shelter from the fishing pressure near the turbines.

The submerged platform surfaces also provide attachment points, hiding spots, hunting grounds, and feeding areas for organisms.

Those changes can help fish and invertebrates share the same space

No bird collisions or bat roosting were reported during the monitoring period.

This does not mean floating wind farms are automatically marine sanctuaries.

WindFloat Atlantic has just three turbines, and the site, fishing regulations and ocean conditions are particular.

Overall, seasonal and interannual variability continued to be the primary driver of marine community variability.

Local coexistence is thus not a general ecological benefit of offshore wind, but rather a description of the researchers.

The size, configuration, fishing access, and adjacent habitat of future projects can vary.

Nonetheless, the observations made over eight years have more evidence than a short survey following installation.

They demonstrate that the arrival of the turbines did not cause the disappearance of marine life.

At first glance, WindFloat Atlantic remains a wind energy installation designed to capture powerful Atlantic winds.

Its meaning is less simple below

The marine landscape remained the same, with octopuses, sole, rays, dolphins, fish, birds and other animals continuing to use it.

Others increased in abundance where fishing pressure was reduced and underwater structures provided shelter.

This doesn’t remove all ecologic concerns about offshore wind.

It does demonstrate that coexistence is measurable, not assumed.

Three turbines continued to produce power, and a much larger community continued to pass through the water around them.