Shrimp being tested for toxins found in harmful algal blooms.

Scientists with the U.S. Geological Survey and Restore the Delta gather shellfish samples collected at Martinez Harbor, Contra Costa County. The shrimp are tested for levels of toxins found in Harmful Algal Blooms (HABs). P. macrodactylus shrimp is an invasive shrimp found in the region and commonly caught in the USGS traps. Two of their identifying characteristics are their distinct rostrum, which is the pointed horn-like feature on their head and their orange joints.