ANNAPOLIS, Md.— The Center for Biological Diversity today sued the Maryland Department of Natural Resources under the state’s Public Information Act for failing to release information detailing exactly how thousands of horseshoe crabs are killed, bled or injured by pharmaceutical companies and fishermen annually.

Horseshoe crabs are threatened with extinction, but because Maryland shrouds in secrecy the process it uses to determine when crabs can be harmed, the Center and other parties can’t meaningfully participate in protecting the imperiled animals.

“It’s outrageous that a shared treasure like horseshoe crabs can be killed and injured at such high levels and that details of these slaughters are then hidden from the public,” said William Snape, an attorney representing the Center. “We’re wiping out one of the world’s oldest and toughest creatures through indifference and brutality.”

Today’s lawsuit was filed in Circuit Court for Anne Arundel County.

Biomedical companies harvest horseshoe crabs and drain their blue blood, which is used to detect toxins in drugs and medical devices. Horseshoe crab blood harvests have virtually doubled since 2017, with nearly 1 million horseshoe crabs harvested for their blood in 2022. Synthetic alternatives to horseshoe crab blood tests are already being used in Europe, but companies in the United States have been slow to adopt the alternatives.

“Lesson one in saving wildlife is to make all take data available to the interested public,” said Snape. “By shielding huge corporate interests from accountability, the Department of Natural Resources is severely harming the horseshoe crab, Maryland’s shared beaches and the residents of Maryland.”

Horseshoe crabs are brown, body-armored arthropods with 10 eyes and a long, spiked tail. Despite their intimidating appearance, they are completely harmless to humans. Each spring along the Atlantic coast, horseshoe crabs lay their eggs in massive beach spawning events.

Nearly twice as old as the dinosaurs, horseshoe crabs have been crawling ashore for more than 450 million years. In the past decades, however, horseshoe crab populations have declined steeply in all states, including Maryland.

Several horseshoe crab mass mortality events have occurred along the Atlantic coast in recent years. A 2021 horseshoe crab die-off in Ocean City, Maryland, resulted in thousands of horseshoe crabs clogging canals. The die-off was specific to horseshoe crabs: No other aquatic species were associated or observed with the horseshoe crab die-off.

Mass horseshoe crab mortality events were observed in Ocean City again in 2022 and 2023. Another horseshoe crab die off was reported at Brigantine Beach, Maryland, in 2022.

The Center petitioned the U.S. Fish and Wildlife Service earlier this year to protect horseshoe crabs under the federal Endangered Species Act.