This measure tracks the number of protected species stocks for which adequate assessments are available. Assessments are vital to determine the scientific basis for supporting and evaluating the impact of management actions. To be deemed adequate, assessments must be based on recent quantitative or qualitative analysis sufficient to determine current stock status based on a variety of data category levels (e.g., life history, threats, stock structure, assessment quality, assessment frequency, and abundance), and conservation status. Stock status projections are highly dependent on survey frequencies, assessment time frames, and fiscal constraints. This measure covers the protected species stocks covered by the Marine Mammal Protection Act (MMPA) or listed under the Endangered Species Act (ESA). The number of such stocks continues to increase as new species are listed and as new stocks of listed species and marine mammals are identified— the latter typically indicates increased knowledge about population stock structure.