During the early mornings of June 8th and 9th, groups of 8th-grade students from the Charles M. Sumner Learning Campus filed off their school bus and onto Prospect Harbor’s mudflats. Quadrants hung off of shoulders, and data sheets flapped in the breeze. A survey of green crab populations was about to take place.
The goal was to count the number of green crabs on the town’s flats. The small crustaceans are invasive and a predator of baby clams. Warming waters have led to a boom in the green crab population and, unfortunately, a big dent in clam numbers. The clamming profession is important to the town, the history of Gouldsboro, and to this new generation of kids. During a tour of Gouldsboro’s Clam Lab, Mike Pinkham, Gouldsboro’s shellfish warden, asked the middle schoolers if they knew anyone who dug clams. Most did.
Each group of kids, led by science teacher Sarah Hooper, carried a quadrant (a 1 by 1 meter square of PVC) and a data sheet to record the size, sex, and shell durability of the crabs. The procedure, developed by Gulf of Maine Research Institute (GMRI), required that the quadrants be placed randomly along a 100m tape. Hooper directed the kids to their first research plot, where they laid down quadrants, took pictures, and began the search. Volunteers and interns aided in keeping everything running smoothly.
Some plots revealed quite a few crabs–seven to nine–while others had none. The average number of crabs per quadrant was about three, while sizes ranged between 7mm and 57mm (more than two inches). The specimens were also overwhelmingly male. Both GMRI and the Gouldsboro Shellfish Resilience team will be able to use the data collected to aid in a better understanding of green crabs.
Despite a few mishaps in the mud, the survey was a success. Kids did science in the real world through an investigation that will be used to track changes in the invasive green crab population. The data is open for public view on GMRI’s website. Teachers Sarah Hooper and Ellen Hall honored the good spirits of the day with a picnic at the Gouldsboro Town Park and a surprise trip to Me And Ben’s Dairy Creme.