A letter from Congress requesting the Government Accountability Office (GAO) investigate the federal government’s response to harmful algal blooms (HABs). The letter asks GAO to investigate the federal government’s response to HABs and hypoxia, including how it is helping state and local governments address the problem, what adaptation methods are being employed, and officials’ plans for studying and addressing the role of climate variability and extreme weather events in exacerbating HABs and hypoxia.