Does the gas turbine include externalities of fabricating, assembling, shipping installing, maintaining, and decommissioning oil drilling rigs? And of shipping, storing, and burning the gas? And the climate change caused by gas leaks? And the harms to humans, the fishing industry, and bird losses and whale harms by oil spills (I know you really care about those)?

The biggest harm to whales is indeed human-based, but more along the lines of being collateral damage from the fishing industry.

The project life cycle cost: yes. The birds and whales: no. But neither do the fossil power plants.

Yes.