Offshore wind specialist Ørsted has commissioned three “industry first” nearshore artificial nesting structures (ANS) specially designed to house kittiwake, a vulnerable species of seabird, off the East Suffolk coastline.
The nearshore ANSs have been installed as part of plans to compensate for potential impacts of the Hornsea 3 wind farm on the species.
Despite a lack of suitable natural nesting sites, such as cliffs, in Suffolk, Black-legged Kittiwake (Rissa Tridactyla) have colonised the area, and populations are expanding.
This makes East Suffolk one of the most likely places for artificial structures to be colonised quickly, Ørsted says, and for the compensation measures to have the highest chance of success.
The structures are located approximately one kilometre off shore – with one close to the Minsmere Nature Reserve and the other two located near South Beach, Lowestoft.
These nearshore locations place the structures close to existing, thriving kittiwake colonies, whilst minimising disturbance to local residents and business owners, according to Ørsted.
Hornsea 3 is the first UK offshore wind project to require ecological compensation.
Each ANS comprises an octagonal topside with capacity for around 500 breeding pairs of kittiwake supported above the water on a single monopile.
The roof pitch and overhang were specifically designed to mitigate avian predators.
The nesting faces have alternating rows of fully partitioned, open, and semi-partitioned ledges.
Ørsted says the experimental design will provide “valuable insight” on the nesting preferences of kittiwake and help inform future compensation projects for the industry.
Individual nesting spaces are fitted with a sliding Perspex panel, which will allow researchers to view the kittiwake from inside the structures without the birds being able to see them, as well as allowing for safe handling for monitoring purposes.
Two cameras have been installed on each ANS to capture birds prospecting and nesting attempts.
Ørsted says it will continue to monitor the existing colonies in Lowestoft and Sizewell for the lifetime of the ANS.
Additionally, Ørsted is providing an initial £50,000 of funding to the Lowestoft Kittiwake Partnership, which aims to safeguard nesting birds.
Suffolk-based Red7Marine took the Principal Contractor role for the fabrication and installation of the structures, working with contract partner Four Tees Engineering to deliver the unique octagonal nesting structure.
All components were delivered to the quayside at Lowestoft for load out onto a jack-up barge before being transported out to location and installed.
‘Could help considerably’
Commenting on the development of the nests, Eleni Antoniou, environmental manager at Ørsted, said: “Kittiwake are listed as at risk from extinction, and with climate change as a key driver to their decline, a move towards a green energy system could help considerably in the long-term conservation of the species.
“In the meantime, the provision of these structures will provide a safe, nesting space to enable future generations to raise young away from predators and out of town centres.
“This is a first-of-its-kind project that required a great deal of collaborative work with stakeholders, architects, engineers, and ecologists to develop a bespoke solution.
“We have already had our first kittiwake visitor to the structures and look forward to seeing our first long-term residents.
“We’d like to thank all those involved in this groundbreaking project so far.”
Image: The nearshore artificial nesting structures, which have been specially designed to house kittiwake. Credit: Red7Marine/Ørsted
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