The Trustees' injury assessment has included hundreds of scientific studies. They have looked at a variety of Gulf habitats, including deep sea sediments, water column, nearshore, and shoreline habitat; and wildlife such as fish, marine mammals, sea turtles, shellfish, corals, and birds, among others. Both private and public lands were adversely affected, including critically important national and state wildlife refuges and parks, and national estuarine reserves. While most of the data collection efforts have been completed, determining the full extent and duration of impacts continues.
Interior is assessing injuries to our trust resources - sea turtles, birds and endangered species such as the Gulf sturgeon, beach mouse, brown pelican, the Kemp's ridley sea turtle, and others. Assessing injury involves everything from staff counting the number of oiled birds and sea turtles (alive and dead) to surveying damage to wildlife habitat such as the dunes and beaches essential to nesting birds and sea turtles. The Deepwater Horizon NRDA injury assessment is the largest ever undertaken; thousands of pieces of data have been collected. For sea turtles, studies have looked at factors such as species locations, distribution, nesting habits, and habitat preferences to assess potential exposure to oil. They also included taking blood and other tissue samples for chemical and toxicological analyses.
For birds, studies have looked at numbers of nests that existed at the time of the spill and in subsequent nesting seasons, colony size and location; documenting numbers of oiled and non-oiled birds; and estimating the number of birds killed.
Interior has taken a multi-facted look at the impacts of the oil spill on the Kemp's ridley sea turtle. The Kemp's ridley work is expected to be particularly helpful because an extensive pre-spill database of Kemp's ridley research provides an important source of baseline information for comparison to post-spill data as part of the NRDA.