Work on a £1.3billion wind farm off the Sussex coast has temporarily halted due to spawning fish.
Laying of foundations for scores of wind turbines for the Rampion Offshore Wind Farm will not resume until July, so as not to disturb shoals of black seabream during spawning season.
Experts are also considering how to deal with unexploded ordnance, which was discovered at the construction site last month.
A spokesman for E.ON, which is delivering the 116-turbine initiative alongside the UK Green Investment Bank, said: “Planned construction of the Rampion Offshore Wind Farm remains on track and is unaffected by the recent unexploded ordnance discovery, for which experts are determining the best course of action.
“We have now installed 18 turbine foundations and, as planned, piling work has now been paused to protect the black bream spawning season.”
A spokesman for the Marine Management Organisation (MMO) said the spawning issue was identified after it received a marine licence application to dispose of unexploded ordnance and relocate boulders.
The MMO placed a condition on the licence, stating ordnance cannot be exploded between April 15 and June 30 in each year of construction.
The spokesman said: “This condition can be varied providing that Rampion can provide sufficient evidence in the form of noise modelling to demonstrate that the detonation of unexploded ordnance will not disturb spawning black seabream.
“The other works which the licence covers – boulder relocation – can still go ahead during the restricted period.”
The MPI Discovery vessel, the large ship used to lay the foundations and pictured above, has left the site until major works resume.
Other work, including surveys and boulder relocation, is still being carried out.