The Trump administration has issued a key fisheries approval for five proposals to shoot oil and gas seismic surveys off the US Atlantic coast, potentially paving the way for the first offshore data collection there in decades that would apply modern imaging technology.

The "incidental take" authorisation -- essentially the government's OK for companies to conduct activity bothersome to marine mammals in a controlled way -- had been caught up in regulatory no-man's land for years since the permits were initially filed in 2014.