One summer night about 40 years ago my friends and I did something only crazy college kids do. We slept on the beach right where Raritan Bay meets the Atlantic Ocean. When the sun came up there were hundred of horseshoe crabs climbing all over us. I was totally grossed out. Horseshoe crabs have been around for millions of years. Scientists believe there are about 25 million living in Delaware Bay alone. What many people don't know is the blue blood from horseshoe crabs has been an essential part of every vaccine produced since the 1960's. That's when scientists discovered the blood was super sensitive to endotoxins. Since then a small amount of blood taken from horseshoe crabs has been added to every vaccine to protect us from bacteria. Now that billions of doses of Covid-19 vaccine are on the way environmentalists are concerned taking too many crabs will seriously damage New Jersey's ecosystem. Although the crabs are returned to the ocean after their blood is taken. Up to 15 percent die. Eggs laid by female horseshoe crabs are food for thousands of migratory birds.