You sound quite skeptical, and seem to be presenting offshore wind as Big Industry riding roughshod over the environmentalists, and that does not fit with reality.

Projects in offshore wind have taken pains from the start to take into account environmental impacts (and indeed that's why many zones are avoided or abandoned, and why plans are modified after studies are done (- as in this case, where the area has been reduced). They are then slapped with additional requirements (is it because other industries don't behave the right way and anything that industry proposes is insufficient by definition?).

Potential impacts have been identified painstakingly, and mitigants are implemented whenever possible, indeed at significant cost (no installaiton over the summer, bubble curtains and the like).

And as noted, the medium term and long term impacts will be largely positive - as offshore wind farms are no-access zones for any kind of activity, they are turning into natural preserves (fish in particular, but not only), and the existing ones have been shown to have no other impact on migratory birds (who avoid them) or big mammals (who come back after leaving for the construction period).

And naturally that ignores the very real impact of having less coal burned in the atmosphere and not sending our money to Russia, Iran or similar...

Wind power