As of 21 June 2010, the area closed to fishing encompassed 86,985 square miles (225,290 km²), or about 36% of Gulf of Mexico federal waters.
In BP's Initial Exploration Plan, dated 10 March 2009, it said that "it is unlikely that an accidental spill would occur" and "no adverse activities are anticipated" to fisheries or fish habitat. On 29 April 2010, Louisiana GovernorBobby Jindal declared a state of emergency in the state after weather forecasts predicted the oil slick would reach the Louisiana coast. An emergency shrimping season was opened on 29 April so that a catch could be brought in before the oil advanced too far. By 30 April, the Coast Guard received reports that oil had begun washing up to wildlife refuges and seafood grounds on the Louisiana Gulf Coast. On 22 May, The Louisiana Seafood Promotion and Marketing Board stated said 60 to 70% of oyster and blue crab harvesting areas and 70 to 80% of fin-fisheries remained open. The Louisiana Department of Health and Hospitals closed an additional ten oyster beds on 23 May, just south of Lafayette, Louisiana, citing confirmed reports of oil along the state's western coast.
On 2 May, the National Oceanic and Atmospheric Administration closed commercial and recreational fishing in affected federal waters between the mouth of the Mississippi River and Pensacola Bay. The closure initially incorporated 6,814 square miles (17,650 km²). By 21 June, National Oceanic and Atmospheric Administration had increased the area under closure over a dozen times, encompassing by that date 86,985 square miles (225,290 km²), or approximately 36% of Federal waters in the Gulf of Mexico, and extending along the coast from Atchafalaya Bay, Louisiana to Panama City, Florida. On 24 May, the federal government declared a fisheries disaster for the states of Alabama, Mississippi and Louisiana. Initial cost estimates to the fishing industry were $2.5 billion.
On 23 June, National Oceanic and Atmospheric Administration ended its fishing ban in 8,000 square miles (21,000 km²), leaving 78,597 square miles (203,570 km²) with no fishing allowed, or about one-third of the Gulf. The continued fishing ban helps assure the safety of seafood, and National Oceanic and Atmospheric Administration inspectors have determined that as of 9 July, Kevin Griffis of the Commerce Department said, only one seafood sample out of 400 tested did not pass, though even that one did not include "concerning levels of contaminants". On 10 August, Jane Lubchenco of NOAA said no one had seen oil in a 8,000 square miles (21,000 km2) area east of Pensacola since 3 July, so the fishing ban in that area was being lifted.
On 31 August, a Boston lab hired by the United Commercial Fishermen's Association to analyze coastal fishing waters said it found dispersant in a seafood sample taken near Biloxi, Miss., almost a month after BP said it had stopped using the chemical.
According to the European Space Agency, the agency's satellite data was used by the Ocean Foundation to conclude that 20% of the juvenile bluefin tuna were killed by oil in the gulf's most important spawning area. The foundation combined satellite data showing the oil spill extent each week with data on weekly tuna spawning to make their conclusion. The agency also said that the loss of juvenile tuna was significant due to the 82% decline of the tuna's spawning stock in the western Atlantic during the 30 years before the oil spill.
The waters had been reopened to fishing on 15 November 2010, but on 24 November NOAA re-closed 4,200 square miles (11,000 km²) area to shrimping. A Florida TV station sent frozen Gulf shrimp to be tested for petroleum by-products after recent reports showed scientists disagreed on whether it is safe to eat after the oil spill. A private lab found levels of Anthracene, a toxic hydrocarbon and a by-product of petroleum, at twice the levels the FDA finds acceptable. On 20 April, NOAA reopened 1,041 square miles (2,700 km2) of Gulf waters immediately surrounding the Deepwater Horizon wellhead to commercial and recreational fishing of fish, oysters, crabs and shrimp after testing results found that 99 percent of samples contained no detectable dispersant residues or oil-related compounds, and the few samples that did contain residues showed levels more than 1000 times lower than FDA levels of concern. This was the twelfth and final reopening in federal waters since 22 July, and opened all the formerly closed areas in Federal waters. Allowable levels for the toxins in Gulf seafood are based on health impacts for a 176 pound adult eating less than 2 medium shrimp per day.
In July 2011 BP released a report claiming that the economy had recovered and there was no reason to believe that anyone would suffer future losses from the spill, with the limited exception of oyster harvesters. However, Bruce Guerra, a crab fisherman in Louisiana for 25 years, said that since the BP oil spill crabbers are trapping 75 percent fewer crabs and that "crabs have been coming up dead, discolored, or riddled with holes since last year's spill". Others in the fishing industry say it could take years to fully realize the spill's effects. "The problem is right when they used the dispersants, that's when the tuna came to the Gulf to spawn," said Cheril Carey, a national sales representative for a Louisiana company specializing in yellow fin tuna. "It takes a tuna five to 15 years to mature. So although we may have fish now, we may not have them in five to 15 years."
In late 2012 local fishermen report that crab, shrimp, and oyster fishing operations have not yet recovered from the oil spill and many fear that the Gulf seafood industry will never recover. One Mississippi shrimper who was interviewed said he used to get 8,000 pounds of shrimp in four days, but this year he got only 800 pounds a week. Mississippi's oyster reefs have been closed since the spill started. A Louisanna fisherman said the local oyster industry might do 35 per cent this year, "If we're very lucky." Dr Ed Cake, a biological oceanographer and a marine and oyster biologist, said that many of the Gulf fisheries have collapsed and "If it takes too long for them to come back, the fishing industry won't survive".