Seiche on marine mammal safety mission at Hornsea Two

Seiche Ltd. has mobilized onboard two vessels at the Hornsea Two offshore wind farm to support marine mammal safety during project construction.

The Seiche team is in charge of ensuring compliance with procedures that seek to minimize the effects of construction noise on the local marine population.

Key species known to occur in the project area are harbor porpoise, white-beaked dolphins, minke whales, as well as grey and harbor seals.

Prior to any construction activities taking place, dedicated Marine Mammal Observers (MMOs) will monitor the area for any animals that could be affected by the noise produced from pile driving.

Monitoring is taking place from DEME’s jack-up vessels during the installation of the monopiles, as well as Heerema’s semisubmersible crane vessel Sleipnir during the construction of the two offshore substations.

In addition to visual monitoring to ensure marine mammals are not within close proximity to piling operations, acoustic deterrent devices (ADDs) are used to deter animals from the area to protect them from harmful levels of noise.

According to Seiche, should a mammal be detected within the designated protection zone piling operations are delayed until it leaves the area.

“We adhere to a strict consenting process before any construction works commence offshore and it’s imperative that outlined procedures are fully adhered to,” said Natalia Lopez, Senior Environment & Consents Specialist for Ørsted.

“It’s great to be able to work alongisde UK based suppliers with specialist expertise in this field so that together, we can deliver the world’s largest offshore wind farm in the most sustainable way possible.”

Hornsea Two will comprise 165 Siemens Gamesa 8 MW turbines located some 89 km north-east of Grimsby.

The 1.4 GW project entered the offshore construction phase in October, while commissioning is scheduled for 2022.