Friday, October 17, 2008

Mudflats


We had a great field trip at Hadley Point this week, where we helped with a student project on clams and collected all manner of worms to look at back in class. More on the worms in a later post. First, we helped Sarah census her baby clams to see if soft-shelled clams, Mya arenaria, exhibit enhanced recruitment in her two treatments (raked and brushed) compared to control plots. Raking roughens the bottom while "brushing," in which small branches of spruce trees are stuck into the mud, provides structure that affects water flow, which may increase the likelihood that clam larvae that are ready to settle out of the plankton encounter the bottom. Using sections of 6 inch PVC pipe to collect core samples, students scooped out the mud and counted all the little clams they found in the sample. I'm hoping Sarah will present her results to the class soon and will also comment here in the blog. Adequate recruitment is only the first step in maintaining a population that's able to be harvested sustainably. Subsequent predation on the baby clams before they reach harvestable size is also an important factor, and some resource managers will seed clam flats with babies from hatcheries or elsewhere, thus ensuring there are plenty of individuals there to start with, and then protect those flats with netting to exclude predators. That's an approach used here on MDI, in Southwest Harbor. Soft-shelled clams are an important component of Maine's fishing industry, although their importance is dwarfed by the commercial lobster fishery. To find out more about Maine's fisheries, including both recreational and commercial, check out the Department of Marine Resources website.

4 comments:

Robin said...

If you follow the link on the latest post on The Loom, there’s a cool gallery of sciency tattoos. Invertebrates, trilobites in particular, are fairly strongly represented. This one has both a ctenophore and a brittle star in it.
http://blogs.discovermagazine.com/loom/science-tattoo-emporium/?nggpage=9&pid=79

Sarah D. said...

I want to say thank you all very much! Your help was greatly appreciated! I was able to finish on Sunday with the help of several wonderful volunteers and I plan to enter my data and run statistical tests later this week. I'll be sure to give an update with my results!
Thanks again!

linda said...

I would just like to say that that picture was totally taken before we started! Look how clean and happy we all are! Not to say that we weren't happy afterward, but we certainly weren't clean...

Sasha said...

On invert tattoos: Milton Love (author of Probably More Than You Want to Know About the Fishes of the Pacific Coast) says that all true biologists have tatoos of their favorite creatures. What might this mean for you?