Have you ever gone to the beach only to find it closed? Across the U.S., many swimming seasons are cut short due to the presence of waterborne pathogens in the ocean. Beaches are monitored to protect public health and prevent illnesses, such as infections, stomachaches, and diarrhea. What are the most common types of pathogens? Bacteria, viruses, and protozoa. How can they enter our coastal waters? Animal feces from birds and dogs, human sources, such as: leaking sewer pipes, untreated wastewater, and run-off from storm water and agriculture and animal production. How do scientists respond? Scientists first collect water samples and survey people at the beach. Back in the lab, they pinpoint the source of the microbial pollution. Advances in biotechnology, by NOAA and its partners, are leading to new detection tools with huge pay offs: early detection and identification of pollution; ability to scan for multiple pathogens at the same time; reduced costs for monitoring and research programs; and most important, faster notification of health threats at public beaches. With the right tools in hand, we can help improve the water quality at our beaches and reduce threats to public health while sustaining a thriving coastal economy.