To estimate the density of the CPOM in small ponds in central Virgina we used an Ekman dredge to collect sediment samples from the littoral and open water regions of Daulton Pond, Lancer Park Pond, Woodland Court Pond, and Wilkes Lake. We collected 2 replicate samples from 3 representative locations in the littoral zone and open water portions for Daulton Pond, Woodland Court Pond, and Wilkes Lake on 13 May 2013, 14 May 2013, and 14 June 2013 respectively. We collected 3 replicate samples each from a single littoral and a single open water location in Lancer Park Pond on 20 March 2013. Finaly we collected a single sample from 3 littoral locations and 6 open water locations in Wilkes Lake on 20 Febuary 2013. In all cases littoral samples were collected between approximately 5 and 20 m from the shoreline but the actual distance was not recorded. The open water samples were collected relatively close to the center of the ponds.
The contents of the ekman was homogeinzed in a plastic basin and a 10 ml sample of the fine sediments was collected with a syringe and placed in a pre–weighed 20 ml glass scintillation vial and dried at 50o C for at least 24 h. The remaining material in the basin was sieved through a 250 \(\mu m\) mesh in the field and the material retained by the sieve was preserved in 70% (v:v) ethanol and transported back to the lab. In the lab the preserved material was passed through a 1 mm sieve and all retained material was dried at 50 oC for 48 h and homogenized with a mortar and pestal. The dried fine sediments and a subsample of the homogenized CPOM was ashed at 550 oC for 4 h to determine the proportion of organic matter in the sample via loss on ignition (LOI). To calculate the ash–free–dry–mass (AFDM) of the total CPOM of the sample the total dry mass was multiplied by the proportion of organic matter in the sample. The areal density of CPOM in the pond was then estimated by normalizing the AFDM of the CPOM to a square meter. We did not estimate the areal mass of organic matter in the fine sediments.