Saturday marks the third anniversary of the explosion at the Deepwater Horizon rig in the Gulf of Mexico. The BP accident left 11 rig workers dead and caused one of the worst offshore oil spills in history.
NWF President Larry Schweiger said scientists are still seeing environmental effects in the gulf ecosystem.
"Just this month scientists announced the spill's underwater oil plume caused a massive die-off of creatures at the base of the gulf's food web," he said in a statement. "It's clear that we will not know the full fallout from the disaster for years."
The first phase of a trial involving the incident concluded in federal court in New Orleans this week. The trial focused on whether operator BP, oil-field services contractor Halliburton or rig-owner Transocean were negligent in the events that culminated in the spill.
Each of the companies involved in the incident tried to blame each other for the accident. Gross negligence would result in a four-fold increase in penalties, The (New Orleans) Times-Picayune reports.
The second phase of the trial should get begin in September.