1. Short title This Act may be cited as the Great Lakes Environmental Sensitivity Index Act of 2017 . 2. Update to environmental sensitivity index products of National Oceanic and Atmospheric Administration for Great Lakes (a) Update required environmental sensitivity index products for Great Lakes Not later than 180 days after the date of the enactment of this Act, the Under Secretary for Oceans and Atmosphere shall commence updating the environmental sensitivity index products of the National Oceanic and Atmospheric Administration for each coastal area of the Great Lakes. (b) Periodic updates for environmental sensitivity index products generally Subject to the availability of appropriations and the priorities set forth in subsection (c), the Under Secretary shall— (1) periodically update the environmental sensitivity index products of the Administration; and (2) endeavor to do so not less frequently than once every 7 years. (c) Priorities When prioritizing geographic areas to update environmental sensitivity index products, the Under Secretary shall consider— (1) the age of existing environmental sensitivity index products for the areas; (2) the occurrence of extreme events, be it natural or man-made, which have significantly altered the shoreline or ecosystem since the last update; (3) the natural variability of shoreline and coastal environment