Metadata file 
3/18/2003 

EEGLE Microzooplankton Abundance (individuals/liter), 1998, 1999, 2000

Microzooplankton (ciliates, including those <20 um, and heterotrophic dinoflagellates) were
sampled from discrete depths (2 at shallow  stations and 3 to 4 at deep stations) using
multiple 10-l Niskin  bottles mounted on a SeaBird carousel water sampler aboard the  R/V
Lake Guardian or a single Niskin bottle (5 or 10 l) aboard the  R/V Laurentian and the R/V
Shenehon.  In March 1998 and February 2000,  triplicate microzooplankton samples were
collected from each station  along the St. Joseph transect to examine variability among
samples. 

Microzooplankton were preserved upon collection in 1% (final concentration)  acid Lugol's
iodine and stored at 4C in opaque containers until processed.   Protists were counted after
settling 25 to 100-ml aliquots in a settling  chamber for at least 18 hours. The chamber was
scanned at 200-400x under  an Olympus IX-70 inverted microscope equipped with Nomarski
differential  interference contrast (DIC), standard working  distance apochromatic optics, 
and a SPOT-2 (Diagnostic Instruments) digital camera.  To verify the accuracy  of our counts
under a heavy sediment load, samples with TSM concentrations >10  mg/l were postfixed with 1%
(final concentration) formaldehyde, decolorized  with sodium thiosulfate, stained with DAPI,
and re-counted using a combination  of dual-band epifluorescence (UV and green excitation)
and DIC. 

Microzooplankton were identified to the species level, whenever possible,  in the settling
chambers using Protargol staining (Foissner et al. 1999)  and in vivo observations.


Contact information:

Peter Lavrentyev
The University of Akron
Department of Biology
Akron, OH 44325-3908

Phone: (330) 972-7922
FAX:   (330) 972-8445
E-mail: peter3@uakron.edu
http://www.uakron.edu/biology/peterl

Reference:

Foissner, W., H. Berger, and J. Schaumburg. 1999. Identification and ecology of  limnetic
plankton ciliates. Bayerisches Landesamt für Wasserwirtschaft.