Thursday, February 25, 2010

Oyster Thursday

Today was a really nice day; I expected to wake up to 3 inches of snow and crazy wind and have to reschedule the myriad work items on my bill, but there was no such snow. Or wind. I had 4 nice observations with 4 burgeoning teachers, and I got to take three of our 4th graders on a mini-field trip. Most of you know a lot about my school already because, like everything in my life, I talk about it A LOT! But, to recap, I work at a petite charter school started by a group of city teachers with a hope for developing a place where city students, of every economic level, could experience an deeply meaningful, hands-on, well-rounded educational career. We have a special focus on environmental science, and we work closely with the Chesapeake Bay Foundation on many conservation projects. One such project is oyster restoration which our fourth grade class champions each year. I have the opportunity this year to work closely with our fourth grade teacher to further develop our curriculum around this project; it's special for me because I love working with intermediate grades, especially this group of kids. I taught them in first grade and again in 3rd grade, so they are very close to my heart.

The fourth graders are raising oyster spat (juvenile oysters) which are currently living in the Baltimore Harbor off a dock owned by Under Armour (who have been so generous to let us use their water-estate). Oysters are interesting little creatures; they are bivalve mollusks, similar to clams and mussels. However, unlike many other mollusks, oysters are sessile. Weeks after the larvae are spawned, they attach to an oyster rock (also called a reef or bar), and remain there for the rest of their lives. As one student said "that's boring and kind of sad". True, perhaps, but oysters have a tremendous task--they filter the bay, removing harmful sediment and toxins. Without them, bay grasses and the creatures that live in the grasses (crabs, rockfish, terrapins...) would die. The current oyster population is at about 3% of what it was 200 years ago, when the waters of the bay were pristine and accounts report that you could dip your hands in the water and pull up several oysters. Obviously the habitat of the Bay is incredibly fragile and all the species are important, but oysters are considered a keystone species. Oyster dredging has always been vital to MD and VA's economy; watermen harvest oysters from the fall-spring and crabs from the spring-fall. The drastic decline in the oyster population has brought about much needed (though highly debated) restrictions to oyster harvesting. But the Eastern Oyster is making a comeback, in part due to tiny little restoration projects like the one our 4th graders carry out each year.

Sorry for the diatribe; I'm fascinated by the Bay and love talking about it :) Every few weeks, I take a group of three students down to Locust Point to check on our oyster spat. Oyster spat grow very slowly, only about an inch a year; our spat are housed in baskets that bob in the (dirty) waters of the harbor. The spat are attached to adult oyster shells, on which they will form a new colony. On our checks, we take a count of how many spat are living and dead and measure a small sample of the spat. Today they ranged from 5mm to 26mm--quite a difference. I snapped a photo that shows the difference in size among the spat:

The kids thought this shell looked like a foot and the spat like toenails!

Unfortunately, I made a grave mistake, though whether it was avoidable could be debated. When pulling up the first of 4 baskets (which are tied to the docks), I realized the latch wasn't closed; all too quickly the 80 or so oyster shells tumbled into the open waters. Ack! Each shell was home to anywhere between 10 and 20 spat meaning I released over 1,000 potential oysters into the harbor; now I am not sure if that means certain death for the little guys. Some might survive the frenzy feeding of little predators. Well, probably not :( It's not the end of the world; at least 20 of the shells landed on a nearby basket, and I was able to put them back into the empty basket. The moral here is that more projects like ours should be spearheaded because surely there are many amateur conservationists like myself who make these sorts of mistakes :) Oh, man.

Be free...ish!

1 comment:

  1. Yay, Shane! Sorry about your little oysters. But I'm so glad you're blogging. I miss you. Heart.