Epifaunal substrate

Rated based on the amount and variety of hard, stable substrates usable by benthic macroinvertebrates. Because they inhibit colonization, flocculent materials or fine sediments surrounding otherwise good substrates are assigned low scores. Scores are also reduced when substrates are less stable.

0 - 5Stable substrate lacking; or particles are over 75% surrounded by fine sediment or flocculent material
6 - 10Large boulders and/or bedrock prevalent; cobble, woody debris, or other preferred surfaces uncommon
11 - 15Abundance of cobble with gavel &/or boulders common; or woody debris, aquatic veg., under-cut banks, or other productive surfaces common but not prevalent/suited for full colonization
16 - 20Preferred substrate abundant, stable, and at full colonization potential (riffles well developed and dominated by cobble; and/or woody debris prevalent, not new, and not transient)

For more comprehensive and detailed information, download the Guide to using MBSS Data (536 KB).