As a flare lit up the Cameron, La., night sky, John Allaire served up etouffee with homemade roux, shrimp, and blue crab plucked from his swampy, birdsong-filled 311-acre property on the Gulf of Mexico.

His trailer’s dinner table was stacked with maps, pollution estimates, letters of dissent to the Federal Energy Regulatory Commission, and handwritten logs documenting busy vessel traffic entering the mouth of the Calcasieu River.