Monday, September 27, 2010

In search of young of the year

One of the projects I'm working on this year is an attempt to study disease in blue crabs during early life history. It is part of a collaboration with Dr. Eric Schott and his students at the University of Maryland Institute of Marine and Environmental Technology.

Blue crab larvae spend their first month or so in the ocean, then migrate into estuaries where they grow as juveniles and mature into adults. Our team has been out a couple of times a month since April searching for young of the year crabs. Juveniles have been relatively easy to catch, hiding in the shallows at the edge of tidal creeks during low tide. "Easy" is a relative term here in the Georgia salt marshes as you can see from the photo.
Megalopae (the larval stage that migrates from the ocean to the estuary) have been harder to come by. After many unsuccessful nights of plankton sampling over the summer, I've finally been catching a few each night that I've been out over the last month. There are far fewer here than where I did my Ph.D. work in Beaufort, NC. In NC we could have caught the several hundred we need for this study in a single night.