Effect of Growth Conditions Upon the Subsurface Transport Behavior of a Ground-Water Protist

By Ronald W. Harvey, Naleen A. Mayberry, Nancy E. Kinner, and David W. Metge

ABSTRACT

A low-nutrient, slightly acidic, porous-media growth procedure was used to grow Spumella guttula, a ground-water nanoflagellate, for an injection and recovery transport experiment involving an organically contaminated aquifer, Cape Cod, Massachusetts. The new growth procedure mimiced conditions within the aquifer and maintained the nanoflagellates' small (2-3 microns [µm]) size. This allowed assessment of its potential for advective transport through the aquifer sediments. Results from the in-situ transport experiment suggest a high transport potential, which was about two orders of magnitude greater than was observed in an earlier experiment using the same nanoflagellate grown in conventional liquid-broth media. The high degree of mobility of S. guttula in the aquifer sediments has important ecological implications for the protistan community within the contaminated aquifer sediments.