The Harmful Algal Bloom and Hypoxia Research and Control Amendments Act of 2013 (S. 1254; Pub.L. 113–121) is a U.S. public law that reauthorizes and modifies the Harmful Algal Bloom and Hypoxia Research and Control Act of 1998 and would authorize the appropriation of $20.5 million annually through 2018 for the National Oceanic and Atmospheric Administration (NOAA) to mitigate the harmful effects of algal blooms and hypoxia. The bill was introduced into the United States Senate during the 113th United States Congress.