This bill, titled the Harmful Algal Bloom and Hypoxia Research and Control Amendments Act of 2025, comprehensively amends the existing 1998 Act to bolster the nation's response to harmful algal blooms (HABs) and hypoxia. It significantly expands the scope of federal activities to include not only coastal waters and the Great Lakes but also all marine, estuarine, and freshwater systems , such as lakes, rivers, and upper estuaries. The legislation broadens the definition of HABs to encompass various types of algae and cyanobacteria, recognizing their diverse ecological, economic, and human health impacts. A central provision requires the Task Force to develop and submit a comprehensive Action Strategy for harmful algal blooms to Congress every five years. This strategy will include scientific assessments of HABs, examine their causes, ecological and economic consequences, and evaluate potential prevention and mitigation methods. It also aims to identify research priorities and improve coordination among federal agencies to avoid duplication of effort. The bill strengthens the National Harmful Algal Bloom and Hypoxia Program by integrating these new assessments and the action strategy. It directs the National Oceanic and Atmospheric Administration (NOAA) to enhance response activities, develop operational forecasting programs, and improve communication for marine, coastal, and Great Lakes HABs. Crucially, it establishes new, dedicated activities for the Environmental Protection Agency (EPA) to conduct research and develop monitoring and forecasting programs specifically for freshwater HABs and hypoxia, ensuring coordination with NOAA where appropriate. Furthermore, the legislation mandates the creation of a National Harmful Algal Bloom Observing Network , integrating existing federal, state, regional, and local observing capabilities for improved monitoring, detection, and forecasting. It also establishes a National-Level Incubator Program to foster the development of novel strategies, technologies, and measures for preventing, mitigating, and controlling HABs. This program will provide merit-based funding and prioritize solutions that protect key habitats, public health, and vulnerable communities, including low-income, rural, and Indian tribal communities. The amendments emphasize consultation with and support for States, Indian tribes, local governments, and affected industries , such as fisheries and agriculture. It authorizes specific appropriations for fiscal years 2026 through 2030 for both the Under Secretary and the Administrator to carry out these expanded activities. The bill also allows for waivers of non-Federal share requirements and provides authority for contracts and grants to support entities responding to events of national significance, recognizing the diverse impacts on subsistence use and local economies.