Influence of Sediment Type and Exposure Time on Likeness of Colonization Tray and Background Macroinvertebrate Assemblages

ABSTRACT

Colonization trays containing three sediment types (formulated, Florissant, and pond) were field deployed in a pond and a stream to assess the influence of sediment type, colonization time, and habitat type on benthic macroinvertebrate colonization. Benthos colonizing the trays was compared to ambient fauna to determine similarity. The pond was chosen as the optimal habitat type. By week 12, organisms colonizing trays in each of the three sediment types placed in the pond were not statistically different from Ekman grab samples in regard to both total abundance and abundance of each dominant taxa. The Florissant-filled colonization trays were the most similar to Ekman grab samples. Percent composition of dominant taxa was most similar (89% based on an affinity index) to Ekman grab samples and had the least variation in composition from the Ekman grab samples. The majority of invertebrates in the stream colonized a superficial layer of debris rather than in the sediments originally placed in the trays.