Fish hotels




TenneT, The Rich North Sea, Ecocean


To enhance biodiversity around their Offshore High Voltage Station (OHVS), TenneT constructs marine nursery habitats. These ‘Fish hotels’ are steel constructed covered with mesh to allow entry to small fish and partly filled with shell or rock, keeping larger predatory fish out, thus providing shelter and safe foraging opportunities for small fish.


• Potential benefits for diverse fish species and crustaceans, including through increased food availability from faecal deposition
• Part of TennetT’s standardised offshore grid design with integrated nature-inclusive measures

About this practice:

TenneT's goal of having zero net impact on nature by 2025 means that positive practices are needed, compensating for any unavoidable negative impacts on the offshore environment. To create new habitat opportunities for marine life around their OHVS, TenneT worked closely with an interdisciplinary team of engineers, cost and maintenance experts, offshore surveyors, ecologists and NGOs ‘Ecocean’ and ‘The Rich North Sea’. The first fish hotels were installed in 2021 and monitoring commenced soon thereafter. Their robust structure makes them transferable to most conditions and geographical regions and TenneT will continue to share the practice with TSOs and industry specialists.

RGI gratefully acknowledges the EU LIFE funding support:

EU LIFE funding support Logo

Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the LIFE Programme. Neither the European Union nor the granting authority can be held responsible for them.