Harmful Algal Blooms (HABs) occur in all coastal states and cause adverse public health, socioeconomic, and environmental impacts. Competitive Research Program funds research on HAB prevention, forecasting, ecosystem and socioeconomic impacts, detection, monitoring, control, and mitigation to provide new tools to federal, state, local, and tribal managers and industry partners. Forecasts predict bloom size and movement, providing early warning to managers. New methods of detecting HAB cells and toxins are improving monitoring capacity. Field tests of bloom control are ongoing. Together, these efforts are making drinking water and shellfish safer and minimizing impacts to tourism, aquaculture, and wildlife.