15 CFR 990.51(b)

Determining injury. To make the determination of injury, trustees must evaluate if:

1. The definition of injury has been met, as defined in Sec. 990.30 of this part; and

2. 1. An injured natural resource has been exposed to the discharged oil, and a pathway can be established from the discharge to the exposed natural resource; or

   2. An injury to a natural resource or impairment of a natural resource service has occurred as a result of response actions or a substantial threat of a discharge of oil.

15 CFR 990.52

Injury assessment quantification.

1. General. In addition to determining whether injuries have resulted from the incident, trustees must quantify the degree, and spatial and temporal extent of such injuries relative to baseline.

2. Quantification approaches. Trustees may quantify injuries in terms of:
   1. The degree, and spatial and temporal extent of the injury to a natural resource;

   2. The degree, and spatial and temporal extent of injury to a natural resource, with subsequent translation of that adverse change to a reduction in services provided by the natural resource; or

   3. The amount of services lost as a result of the incident.

3. Natural recovery. To quantify injury, trustees must estimate, quantitatively or qualitatively, the time for natural recovery without restoration, but including any response actions. The analysis of natural recovery may consider such factors as:
   1. The nature, degree, and spatial and temporal extent of injury;
      
   2. The sensitivity and vulnerability of the injured natural resource and/or service;
      
   3. The reproductive and recruitment potential;
      
   4. The resistance and resilience (stability) of the affected environment;
      
   5. The natural variability; and
      
   6. The physical/chemical processes of the affected environment.

1. Injury Determination phase.

   The purpose of this phase is to establish that one or more natural resources have been injured as a result of the discharge of oil or release of a hazardous substance. The sections of subpart E comprising the Injury Determination phase include definitions of injury, guidance on determining pathways, and testing and sampling methods. These methods are to be used to determine both the pathways through which resources have been exposed to oil or a hazardous substance and the nature of the injury.

2. Quantification phase.

   The purpose of this phase is to establish the extent of the injury to the resource in terms of the loss of services that the injured resource would have provided had the discharge or release not occurred. The sections of subpart E comprising the Quantification phase include methods for establishing baseline conditions, estimating recovery periods, and measuring the degree of service reduction stemming from an injury to a natural resource.