Parallel single-species and stream mesocosm exposures for grading… Posted by Bar Harbor News | June 15, 2016 | 0 | Nietch, C., J. Lazorchak, B. Johnson, N. Smucker, P. Weaver, S. DeCelles, AND S. Guglielmi. Parallel single-species and stream mesocosm exposures for grading major ion effects in doses mimicking energy extraction produced waters.