Citizen Science: Count the Gulf’s Ghost Crabs

Brandon Keim Wired Science 23 Jun 10;

While the oil disaster’s terrible toll on birds and turtles will at least be measured, less charismatic creatures tend to be ignored. That’s why conservationists are organizing a citizen science project to count the Gulf Coast’s ghost crabs.

Also known as sand crabs, they’re not classically cute, but they’re an important part of coastal food webs. Because the crabs are relatively easy to spot, it’s possible for people to help scientists estimate their numbers, providing baseline counts for comparison against future surveys.

“A lot of people are speculating that this spill could have severe effects on marine invertebrates,” said Drew Wheelan, a conservation coordinator for the American Birding Association, who came up with the idea for a ghost crab count. “Ghost crabs are conspicuous and easy to count.”

Wheelan modeled his project after an ongoing Gulf Coast bird count organized by the Audubon Society and Cornell Lab of Ornithology. Since early May, birders have submitted approximately 150,000 observations from Gulf states. That data will be invaluable to scientists trying to quantify the oil’s impacts, especially in areas where precise population counts didn’t previously exist.

University of Florida zoologist Sea McKeon designed the ghost crab-counting methodology, which is described on Wheelan’s blog, along with instructions for submitting data. It involves measuring distances between tideline crab burrows at a specific time and place each day for as long as possible, and requires little more than a measuring tape, notebook and pen, GPS reading and some sunscreen.

Wheelan said counts need to start as soon as possible in areas where oil hasn’t yet come ashore. Pre-disaster data is needed, and BP — which is trying to bar journalists and citizens from many affected areas — may close beaches as oil approaches.

Wheelan is still counting birds, too. During an ABA film project, Wheelan was interrogated by a policeman who appeared to take orders from BP.

But for now, “at least in Florida and Alabama and Mississippi, people are still able to travel on beaches” and count crabs, said Wheelan.