What is the importance of horseshoe crabs?

• A. 500-yard approach limit by law
• B. Ecological role, biomedical use
• C. Provide habitat near coast
• D. Protected, avoid disturbing nests

Answer: (B)

Horseshoe crabs matter because they link coastal ecosystems with human health. Ecologically, their eggs on beaches provide a vital food source for migratory shorebirds during their long journeys, helping sustain bird populations that rely on coastal habitats. The spawning cycle also contributes nutrients to beach and dune ecosystems, supporting a healthy coastal environment that paddlers and wildlife depend on.

Beyond ecology, their blue blood has a unique biomedical use. The blood contains substances that clump around bacterial endotoxins, enabling the Limulus amebocyte lysate test to detect contamination in vaccines, medical equipment, and medications. This medical role has made horseshoe crabs incredibly valuable to public health and sterile medicine.

The other options miss this broader significance. While horseshoe crabs do occur on beaches and are protected in some areas, the most important reasons people study and protect them are their ecological role for shorebirds and their essential biomedical use.