GULF OF MEXICO — At the height of the oil spill, more than one third of the Gulf’s federal waters were closed as a precaution, amid fears of what the oil could be doing to the water and marine life.

Since then, 40,000 square miles of the Gulf have reopened, though the initial closures prompted calls for testing, especially of seafood.

“We’re making good progress and sampling very, very carefully, making sure areas that we are reopening is in fact safe to reopen and that the seafood is free of contaminants,” said Jane Lubchenco, head of the National Oceanic and Atmospheric Administration.

Multiple agencies are involved in that seafood testing. However, the job mainly falls to NOAA, in conjunction with the Food and Drug Administration. Yet, now, some independent scientists are expressing concerns that the seafood testing falls short of being thorough — even though government officials have said Gulf seafood is safe to eat.