Under Section 7 of the ESA, Federal agencies must consult with NMFS and/or the USFWS when an action the agency carries out, funds, or authorizes (such as through a permit) may affect a listed endangered or threatened species and/or designated critical habitat. The purpose of the consultation is to assist the action agency in meeting its duty to insure that its action is not likely to jeopardize the continued existence of any listed species or result in the destruction or adverse modification of designated critical habitat. Upon completion of consultation the USFWS and/or NMFS provides the action agency with either a letter of concurrence that the proposed project is not likely to adversely affect any listed species or a biological opinion. If the biological opinion concludes that the project is not likely to jeopardize the continued existence of any listed species and is not likely to result in destruction or adverse modification of critical habitat for any listed species, the USFWS and/or NMFS also provides an incidental take statement including terms and conditions, which if complied with, provide an exemption from the ESA's prohibitions on incidental take of listed species. If the biological opinion concludes that the proposed action is likely to jeopardize the continued existence of any listed species (or result in the destruction or adverse modification of designated critical habitat), the USFWS and NMFS develop reasonable and prudent alternatives that would avoid jeopardy or adverse modification that are shared and discussed with the action agency prior to completion of the biological opinion. NOAA generally manages marine species. The USFWS generally manages freshwater and terrestrial species. NOAA and the USFWS share responsibility for sea turtles, Atlantic salmon, and gulf sturgeon.