Date of Award

Fall 1981

Document Type


Degree Name

Master of Science (MS)


Biological Sciences



Committee Director

Harold G. Marshall

Committee Member

Joseph H. Rule

Committee Member

Raymond W. Alden, III

Committee Member

Daniel M. Dauer

Call Number for Print

Special Collections LD4331.B46 J33


Copper levels and dominant phytoplankton species composition were examined from six sites in Kings Creek on Virginia's Eastern Shore from March to August 1980. Creek copper levels were determined by an APDCMIBK extraction procedure and ranged from 0.003 to 0.020 mg/1. Diatoms were the dominant phytoplankters with Skeletonema costatum (Greville) Cleve emerging as a major late summer species.

Subsequent laboratory studies involved 96-hour experiments using Skeletonema costatum (clone Skel) grown in enriched natural seawater. The water was collected from Kings Creek and enriched to Guillard and Ryther's (1962) f/2 media levels. Cupric sulfate was added to the experimental culture media from stock solutions yielding final copper concentrations of 11.7 uM, 13.7 uM, 15.7 uM, 17.7 uM and 31.5 uM. The S. costatum cells exposed to copper for 96 hours were harvested, digested and analyzed for cellular copper content. The copper content of control cells was below detection limits, whereas copper exposed cells had copper levels which ranged from 576 to 8929 ug/g dry weight. Cell-free and cell-containing culture media were analyzed for total and chelated copper levels using Chelex-100 in ion-exchange columns. Total and chelated copper levels in cell-free media ranged from 0.004 to 1.781 mg/1 and 0.004 to 0.492 mg/1, respectively, while total and chelated copper levels in cell-containing media ranged from 0.004 to 0.857 mg/1 and 0.004 to 0.466 mg/1, respectively.

Generally, the percentage of chelated copper was slightly higher in cell-containing than in cell-free media, possibly due to Skeletonema costatum modifying the media by releasing extracellular metal binding organics. The copper concentration of S. costatum cells grown in copper spiked media increased with increasing media copper levels. The cellular copper concentration factors ranged from 882 to 9765.


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