In the US, vaccines are composed largely of Horseshoe Crab blood. These crabs are captured from the wild and have a third of their blood drained. They are released after this, but most don't survive and the ones that do produce less eggs. Will the populations of Horseshoe Crabs and the birds...
The American Red Knot (subspecies rufa), declined 25% this season due to shortages in Horseshoe Crab eggs:
Red Knots plummet by 25% in a year in Tierra del Fuego