How Citizen Scientists are Protecting Horseshoe Crabs
Microbial Solutions
Mary Ellen Mateleska

How Citizen Scientists are Protecting Horseshoe Crabs

More than 2,500 individuals have participated in evening population counts, midnight tagging events and marine debris removal activities.

[inlinetweet prefix="" tweeter="" suffix=""]Citizen Science can be a polarizing topic within the scientific community[/inlinetweet], but it also allows organizations to bridge the gap between researchers and the public. With a mission to inspire people to care for and protect our ocean planet through research, education and conservation, Citizen Science provides the Mystic Aquarium an opportunity to engage a wide audience in all three aspects of our mission.

For over 10 years, we have partnered with community organizations to support the collection of horseshoe crab population data for Sacred Heart University’s Project Limulus, so-named for the genus of horseshoe crab found in the Atlantic. More than 2,500 individuals have participated in evening population counts, midnight tagging events and marine debris removal activities. This collaboration between professionals and the public allows for significantly more data on species distribution, mortality and human impact than what a single research team could possibly compile on its own.

The horseshoe crab, itself, has served as a conduit for scientists and citizens. Participants increase their knowledge of horseshoes crabs and expand their skills at collecting and interpreting the data. In the process they help create a community of environmentally literate individuals. We have seen participants change personal day-to-day behavior, become an active advocate for policies protecting local coastlines, and join other on-the-ground stewardship endeavors. In fact, it is this group of individuals who have challenged the Aquarium to play a more active role in horseshoe crab conservation.

Horseshoe crab populations in Connecticut are primarily impacted by bait harvesting, habitat destruction, and land-based predators. Sadly, over the past three years, a marked increase in dead horseshoe crabs have been found during population study counts at Bluff Point State Park in Groton, the only sizeable, mostly undeveloped public coastal land remaining in the state. This past season, over 40 horseshoe crabs were found dead along the coastline, twice the yearly average. Photos from concerned citizens confirmed the mortalities were the result of bait harvesting and predators, probably raccoons, foxes, and gulls.

As both demand for these animals and mortality increase, scientists and Citizen Scientists are looking to ensure that the horseshoe crab population remains stable. In response, Mystic Aquarium is partnering with Project Limulus and Charles River Laboratories to elevate local horseshoe crab conservation efforts by bringing increased awareness, through educational events and ongoing research and development projects, the pivotal role horseshoe crabs play in our ecosystem and the valuable contribution they make to biomedical research community.

During monitoring events, Mystic Aquarium and Citizen Scientists will continue to visit local beaches to search for and tag horseshoe crabs that descend upon local beaches to mate and lay eggs. Participants will then have the option to join Aquarium staff on a later date to collect a small selection of horseshoe crab eggs, which will be reared at the aquarium in a public display. This breeding activity will support a much larger endeavor involving the release of reared crabs that hopefully will boost horseshoe crab populations in impacted areas.

In the case of the Atlantic horseshoe crab, every year there seems to be more notoriety surrounding this remarkable species. Whether you are an animal lover, a private non-profit such as Mystic Aquarium, a government agency or a responsible drug manufacturer, we invite you to help get the word out about these amazing creatures, the role they play in our lives every day and what we can do to protect them.

How to Cite:

Mateleska, Mary Ellen. How Citizen Scientists are Protecting Horseshoe Crabs. Eureka blog. Aug, 16, 2016. Available: