A Die-Off of Horseshoe Crabs

I've been fond of horseshoe crabs since I discovered them here on Cape Cod; I never saw them before. They are "fossil" creatures, not really crabs. One shell decorates my wall -- painted by Rachel with an oriental face. en she and Patrick first came to the Cape they used all their artistic skills to earn a bit here and there. Rachel came upon the idea of painting these faces on the shells of molted horseshoe crabs, and sold quite a few for a couple of years. 

That was then (25 years ago). Now I am here and walk on Long Beach and each August observe the many sizes and colorations of the molted shells I find lying on the beach.  Some are quite small, some are huge and encrusted with other crustations, occasionally one is black with age (or polluted seabed ).  Sometimes there have been enough that I and other people gather them into "conventions" like the picture here.

Last week, after the very high tide that came with the very huge summer moon, I walked on the beach early in the morning and saw, in the sea wrack at high tide line, literally hundreds of shells (and not all empty, many with dead crabs in them).  They were nearly all the same size, about as big as my hand, all the same young shade of beige. There were no big ones among them and certainly no ancient ones. They seemed to be the same age. I'm no expert at all but I guess about three years old.  The strewn shells at tide level stretched for a good half mile.  I did not attempt to count them, it was more than hundreds. 

Again I saw Stehanie as I was returning toward the parking lot. She was aghast as was I. Who could answer the question: why? We didn't know. She felt the Cape Cod Times would be unwilling to print anything about  an obvious die-off which would hint that something might be wrong with the water, at high tourist season. I don't read the paper so I don't know if they have written anything. I called the Woods Hole Oceanographic Institute because they surely have someone knowledgeable about these creatures that were here before the dinosaurs. But it's summer; the operator didn't know to whom to direct me and the Information Center was manned by a young woman who was "filling in." She said she would leave a message to whomever.  I got a call the next day suggesting I call the town enrvironmental director since this person thought it might be the water also. I met other locals on the beach who were concerned and had said they would call "somebody". I was remiss and did not make more calls. (I admit to a nearly neurotic aversion to making phone calls -- imagine that in this day and age of everyone on their smart phones. Well, not me, I don't have one and don't want one.)

So it's a mystery and perhaps an answer will turn up -- after the tourists are gone.