The April 2010 Deepwater Horizon oil spill, or BP oil spill, had far-reaching and catastrophic environmental effects. According to a 2013 study [PDF] published by the National Academy of Sciences, it is difficult to know the full extent of environmental damage caused by the spill because of the movement of ocean currents and the difficulties of monitoring the great variety of natural resources found in the Gulf of Mexico. In addition to the challenges of every incidence of environmental damage, it is no easy task to assess the damage in economic terms. Furthermore, the National Research Council expressed concern about the unknown environmental effects of products used to clean-up the oil, primarily the massive use of dispersants to break up the oil in the water, on the Gulf’s ecosystem. The study, requested by the US Congress, also warned that the environmental impact of the oil spill would exert a substantial impact on the Gulf’s economy as well, because many residents of that region relied on the Gulf’s varied natural resources for survival.

Some groups have set out to identify specific damage caused by the oil spill. For example, a 2013 study by the National Wildlife Federation (NWF) noted that the Gulf’s bottlenose dolphin population was suffering from severe illnesses caused by exposure to the oil spill. The NWF also observed decreases in the population of the Gulf’s marine wildlife caused by the oil spill adversely affecting hatcheries and interfering with the aquatic ecosystem’s food chain. The Department of the Interior reported similar environmental impacts, including negative effects on waterfowl populations and oyster beds. Scientists that used submersible equipment to study coral located near the Deepwater Horizon site witnessed extensive damage to coral beds caused by the blowout and spill. Environmental group Greenpeace obtained photographs of a dead sperm whale found in the Gulf in the weeks following the oil spill, allegedly killed by the effects of the spill, through a FOIA request.

In addition to the diverse wildlife population, many human residents and industries of the Gulf Coast region rely on the natural resources and suffered from the spill’s environmental effects. Fishermen in the region are bringing in reduced hauls of seafood and noticing the reduced populations of commercial seafood species. Some of the seafood brought in by fishermen continues to display notable deformities and has caused concern about the consumption of contaminated food on the human population. Scientists also express concern about the impact of toxic dispersal chemicals used in the Gulf on the human population, especially as humans consume seafood from the Gulf that has been exposed to the toxic chemical’s lingering effects. Gulf Coast beaches, a major tourist attraction for the region, periodically suffer from “tar balls” washed ashore after storms. While many of the catastrophic environmental effects of the BP oil spill remain largely unknown, such studies are important for calculating the economic damages caused by the spill attributable to BP.