


Journals 2005/2006

Judy Reeves
Baldwin County High School, Bay Minette, Alabama

"Monitoring and Assessment of Tidal Creeks"
Hollings Marine Lab, Charleston, South Carolina
August 1-12, 2005
Journal Index:
August 1 - 2 - 3 - 4 - 5 - 6/7 - 8 - 9 - 10
           11 - 12

August 11, 2005
Sorting the samples

Most of today was spent in the sorting lab at DNR (Department of Natural Resources). Here we take all the samples from the seines and the sediment cores, and get rid of all the debris so the organisms can be identified and counted. I was so pleased to find something I could do well-hooray! I sorted 5-6 seining samples from this summer's fieldwork. Patrick and Jon were terrific-showing me how to do everything, and then just there to answer all my questions. Patrick would check out each sample with me after I got it prepared, to point out the new organisms and how to identify them. He showed me isopod parasites under a shrimp's gills (and I saw plenty of them after he pointed them out!) There were white and grass shrimp, marsh snails, blue crabs and marsh crabs, mummichugs, menhaden, spots, and various other critters. The process of identification is very meticulous to give validity to their data. Sometimes a sample would have hundreds or thousands of organisms to identify and count. It really made me appreciate why we try to clear out debris from the seining samples before preserving them. I would have been even more thorough after this!

DNR gave me some great posters for my class-everyone has been so nice and helpful.

This afternoon, I looked up Paul Pennington again. Laura Webster from Pathogen Tracking had introduced him to me on the first day, and I was fascinated with his project. He has a greenhouse full of mesocosms, middle scale ecosystem models of tidal marshes. A pump and timer simulate tidal ebb and flow in the marsh in what are essentially big aquaria, with grass shrimp and marsh snails in the water, and Spartina and Juncus at different levels above the water. Perfect setups for performing pollution, salinity, or crowding experiments! They use them for pollution studies, but I kept thinking how my kids could build these for my greenhouse.

Today we talked nuts and bolts of building the systems, and he found me several reprints, and promised to help me if I ran into problems. I took lots of pictures, and even emailed my aquaculture consultant from Sea Grant!

Mesocosm-note the different levels for Spartina and Juncus, just like in the marsh!   To simulate tidal patterns, the water is lowered to the sump for ebb tides and raised for flood tides.

The only lab I haven't mentioned is Environmental Chemistry, which uses sediment samples to check for organic and inorganic contaminants in the tidal creeks. They use gas chromatography to space out the components, spectrophotometry to separate the compounds, and then more testing on the same machines to separate the peaks into different organic compounds or inorganic ions. They can test qualitatively or quantitatively. There are separate analyzers for organic and inorganic, and one especially for vaporizing mercury! The main inorganic contaminants they look for are mercury, chromium, and arsenic. The organic setup is much the same, and they can test for 170 compounds of interest! It takes about a week from drying the sediment to analysis. Another brand-new machine which uses glass stirring rods with the sample concentrated on the rods only takes about ten hours! The labs are a chemist's dreams come true-real cutting edge stuff here. But expensive! Ed Wirth told me they tested 60 sites in the Chesapeake Bay this summer at a cost of $250,000. It will take four months before the final reports are submitted analyzing the data.

I asked Susan Lovelace and Anne Blair to join me for dinner on this my last night. They have been wonderful! This has been a great experience, due in no small part to these two extraordinary women. I hope we can stay in touch. I promised to come out and say good-bye in the morning.