DMF announces horseshoe crab closure dates

Commercial horseshoe crab fishing will be closed April 24-28 and during each new and full moon in May and June. — Nelson Sigelman

To promote the conservation of horseshoe crabs, the Massachusetts Division of Marine Fisheries (DMF) has announced closure dates for the commercial horseshoe crab fishery during spawning periods in April, May, and June.

Harvesting will be prohibited during five-day lunar closure periods coinciding with the second lunar period in April, from April 24 through April 28. Closures during May and June will be during each new and full moon — May 8 through May 12, May 23 through May 27, June 7 through June 11, and June 21 through June 25.

Closures will begin at 12 am (midnight) two days prior to the new or full moon and end at 11:59 pm two days after the new or full moon. The DMF lunar calendar is derived from NOAA data.

“Horseshoe crabs are very valuable to the biomedical industry, and their eggs are an important source of nutrition for shorebirds,” DMF policy director David Pierce told The Times. “These lunar closures also enable us to do surveys, but they’re easily picked off the beach, so without the closures it’s hard to get a good reading on the population.”

Horseshoe crabs are sometimes called “living fossils” because fossils of their ancestors date back almost 450 million years — 200 million years before dinosaurs existed.

The full text of the regulations relevant to horseshoe crabs can be found at 322 CMR 6.34. More information regarding horseshoe crabs is available at the DMF website,