Seeing Red

Dave Kulis and Liann Correia, research assistants in the lab of biologist Don Anderson, retrieve a CTD—an instrument that measures conductivity, temperature, and depth—from Salt Pond, part of the Cape Cod National Seashore’s Nauset Marsh system. In early May 2015, a large bloom of the toxic dinoflagellate Alexandrium fundyense, or red tide, occurred while the researchers were monitoring the pond and is visible here as bands of reddish-brown water. As part of the Anderson Lab’s ongoing study of harmful algal blooms in Nauset Marsh, this program helps regulatory agencies determine when to close shellfish beds to protect public health.(Daniel Cojanu, UnderCurrent Productions ©Woods Hole Oceanographic Institution)