07/31/2013 Env Bd Packet - Laserfiche WebLink

Home Search

• • Locke Lake `Above' Data Summary Family Biotic Index (FBI): Our 2012 SHEP field sampling results produced a score of 5.2 for the Locke Lake `Above' site. This score corresponds to a "Fair" rating on the Family Biotic Index stream health chart. This shows some improvement in stream health scores from 2010 (5.9) and 2011 (5.2). In 2012, the diversity increased, and the dominating family was modest. Despite the lack of EPT families in the sample, more families with lower tolerance to pollution were present in the sample. Number of individuals: A large sample offers more confidence for a more reliable data set. SHEP protocol requires a minimum of 100 individual invertebrates to be picked and identified per sample. 314 invertebrates were identified in this sample. This sample size is excellent. Dominant Family: The dominant family was Chironomidae. Chironomidae dominated 29.3% of the sample, and has a tolerance value of 6 on a scale of 0 -10 (the lower the tolerance value, the lower their tolerance to pollution). They are a very abundant and diverse group of aquatic insects, and it is common for them to dominate samples (Guide to Aquatic Invertebrates of the Upper Midwest, R.W. Bouchard, Jr). Number of Families: In 2012, 18 families were identified in the sample. This compares to 12 families in 2011 and 13 families in 2010. In general, a more diverse sample suggests a healthier stream environment. EPT: Ephemeroptera - Plecoptera - Tricoptera (Mayfly - Stonefly - Caddisfly) are three Orders of invertebrates with low tolerance to pollution. The more of these families in a sample, the better. More than 10 -12 families is considered good. In 2012, 6 EPT families were identified and made up 45% of the sample. 4.4.4b Field Sampling Results for Locke Lake `Below' Site Historical Field Results for Locke Lake `Below' Site Date # Identified Family Biotic Index EPT # of Families Dominant Family Dominant Family % Overall Field Samp ing Results: 9/28/06 111 5.3 3 8 Chironomidae 43% 9/16/07 257 5.7 2 9 Chironomidae 36.6% 10/11/08 315 5.1 5 13 Hydropsychidae 41% 9/13/09 498 5.0 2 12 Hydropsychidae 48% 9/12/10 197 5.0 5 11 Chironomidae 42% 9/11/11 2536 5.7 3 13 Simuliidae 80% 9/9/12 629 5.6 3 15 Chironomidae 61.4% Cross Check Results: 10/8/06 137 4.3 3 10 Hydropsychidae 85% 9/22/07 87 5.4 2 9 Gammaridae 23% 10/2/10 100 5.6 3 12 Simuliidae 33% 9/3/11 205 5.1 4 12 Chironomidae 35%