Streamwatch Project
West Branch of White Clay Creek: Site 19
Site 19 is the headwater site on the West Branch located upstream from State Road in New London Township, PA. Similar to the other study sites, this site is dominated by open uncultivated fields. In contrast, Site 19 had the highest amount of row crops (10% more than the study wide average). Fertilizer application to these agricultural fields may be the reason that nitrate levels were so high, although phosphorus, another potential byproduct of fertilizer, was not.
Macroinvertebrate densities ranged from 2300 individuals/m2 in 2003 to 25,400 individuals/m2 in 2008 and average 12,000 individuals/m2. EPT on average made up 28% of the total numbers and averaged 3300 individuals/m2. EPT taxa made up approximately 48% of the Total Richness, which average 14 taxa/200 individuals. The average MAIS score was 10.1 or Fair. There was one year (1997) it rated Poor (5.6), 8 years it rated Fair (6.4-12.7), and 2 years (1998 and 2003) it rated Good (13.4-15.4). The high variability in the MAIS score at this site gives no indication whether the macroinvertebrate community is improving or not.
| Location | |
|---|---|
| Site number | 19 |
| Description | Upstream from State Road in New London Township |
| Lat Long (hr min sec) | 39°47.882’ N, -75°51.611’ W |
| Land Use | |
| Watershed area above site (km2) | 4 |
| Population density in 2000 (#/km2) | 117 |
| % Population increase from 1990 to 2000 | 29 |
| Percent pasture/hay | 50 |
| Percent cultivated crops | 31 |
| Percent forest | 13 |
| Chemistry* | |
| Nitrate (mg/L) | 7.11 |
| Ammonium (mg/L) | 0.03 |
| Total Dissolved Phosphorus (mg/L) | 0.018 |
| Soluble Reactive Phosphorus (mg/L) | 0.050 |
| Sulfate (mg/L) | 11.48 |
| Alkalinity (as mg/L CaCO3) | 30.89 |
| pH | 7.35 |
| Conductivity (μmhos) | 210 |
| Dissolved organic carbon (mg/L) | 2.65 |
| Macroinvertebrate Data | |
| years sampled | 1994-2000, 2003-2004, 2008 |
| MAIS score | 10.1 |
| water quality based on MAIS score | Fair |
 Click on macroinvertebrate name to view a photo | |
| 1st most abundant macroinvertebrate | Chironomidae (midges) |
| 2nd most abundant macroinvertebrate | Ephemerellidae (spiny crawler mayflies) |
| 3rd most abundant macroinvertebrate | Elmidae (riffle beetles) |
| 4th most abundant macroinvertebrate | Hydropsychidae (common netspinner caddisflies) |
| 5th most abundant macroinvertebrate | Oligochaeta (aquatic worms) |
*See Methods for number of years each chemistry variable was measured.