Streamwatch Project

Middle Run and Lower Mainstem of White Clay Creek: Site 20

Site 20 is located near Creek Road at the Delaware Visitor Center in White Clay Creek State Park. Like most sites in the watershed the main land uses are pasture/hay, crops and forest. Water chemistry variables are comparable to the study wide mean and indicated no obvious problems.

On average 85% of the total density were chironomid midges (7600 midges/m² versus 8800 total individuals/m²). EPT richness was very low, only 2 taxa/200 individuals, at reference Site 11 the average was 8 taxa/200 individuals. Total Richness averaged 8 taxa/200 individuals. The MAIS score averaged 4.1, which rated this site as Poor.

Location
Site number	20
Description	At the Delaware Visitor Center near Creek Road in White Clay Creek State Park
Lat Long (hr min sec)	39°43.658’ N, -75°45.946’ W
Land Use
Watershed area above site (km2)	165
Population density in 2000 (#/km2)	163
% Population increase from 1990 to 2000	34
Percent pasture/hay	49
Percent cultivated crops	17
Percent forest	23
Chemistry*
Nitrate (mg/L)	3.58
Ammonium (mg/L)	0.01
Total Dissolved Phosphorus (mg/L)	0.038
Soluble Reactive Phosphorus (mg/L)	0.054
Sulfate (mg/L)	27.87
Alkalinity (as mg/L CaCO3)	62.44
pH	8.11
Conductivity (μmhos)	294
Dissolved organic carbon (mg/L)	2.20
Macroinvertebrate Data
years sampled	1995-1998, 2000, 2001, 2003-2005
MAIS score	4.1
water quality based on MAIS score	Poor
	Click on macroinvertebrate name to view a photo
1st most abundant macroinvertebrate	Chironomidae (midges)
2nd most abundant macroinvertebrate	Tipulidae (crane flies)
3rd most abundant macroinvertebrate	Hydropsychidae (common netspinner caddisflies)
4th most abundant macroinvertebrate	Oligochaeta (aquatic worms)
5th most abundant macroinvertebrate	Hydroptilidae (microcaddisflies)

*See Methods for number of years each chemistry variable was measured.