A minus 4 1/2-foot tide drew us out to check the intertidal zone. As we strolled across a wide sandy stretch at the water’s edge, we were startled to see a frond of rockweed steadily disappearing into the sediments.
A few steps later, another algal frond went quickly down and was gone from our view. Then it happened again.
Some buried critter was pulling in algae, but who could it be? The most likely perpetrators were horse clams, withdrawing their siphons as our steps shook the sands and thus pulling down algae that were attached to the siphons.