Huntingdon, Pennsylvania Study of Oxygen Depletion and Negative Heterograde Formation in Raystown Lake, PA Sharon Simpson Juniata College Huntingdon, Pennsylvania Advisor - Chuck Yohn

Raystown Lake Reservoir created by Raystown Dam Located in Huntingdon and Bedford Counties 27 miles long, 118 miles of shoreline 8,300 acre surface area

Spring Oxygen and Temperature Profile Lake mixes completely in the spring. Mixing oxygenates the lower depths of the lake.

Typical Oxygen and Temperature Stratification Lake stratifies in summer No oxygen inputs to the lower depths of the lake. Respiration consumes oxygen. Oxygen profile measures the health of the lake.

Typical Oxygen and Temperature Stratification Epilimnion Metalimnion Hypolimnion

The Two Issues Anoxia Negative heterograde

Research Questions What is the extent of the oxygen depletion? Where are the inputs of the oxygen depleting materials? What is the extent of the negative heterograde? Why is the negative heterograde forming?

Oxygen Depletion Hypotheses Input of oxygen demanding materials From where? 1. Recreational use 2. Sediment sliding 3. Stream input

Research Design Where are the low DO values? Where is the highest rate of depletion? Sampling sites 5 Main channel sites (sediment sliding) 4 Sites near marinas and campgrounds (recreational sites) 6 Sites in bays of tributaries (stream input sites) Sampling Once a week, May to November Temperature, DO, and % saturation with YSI DO meter Readings every 1 m until the bottom or 29 m Data collection completed within 1-3 day time span

Sampling Sites

July 13, 1998 C1 Raystown Dam Mile 0 I1 Snyder’s Run Mile 2

R1 Seven Points Marina Mile 10.5 July 13, 1998 C2 Mile 6 R1 Seven Points Marina Mile 10.5

R2 Seven Points Marina Mile 10.7 July 13, 1998 R2 Seven Points Marina Mile 10.7 C3 Mile 13

July 13, 1998 I2 James Creek Mile 14 I3 Trough Creek Mile 14.8

July 13, 1998 C4 Mile 18 C5 Entriken Bridge Mile 20

R4 Lake Raystown Resort Mile 21.5 July 13, 1998 R4 Lake Raystown Resort Mile 21.5 I5 Shy Beaver Creek Mile 21.8

July 13, 1998 I6 Juniata River Mile 24

r = -0.93, p <0.00

Nitrates used as an indicator of nutrient concentrations. High nutrient concentration causes oxygen depletion. r = 0.88, p < 0.00

Conclusions The major source of oxygen depleting materials to Raystown Lake is at the input of the Juniata River. There was no difference in oxygen depletion among the three groups of sites. The oxygen depletion pattern is not uncommon for reservoirs (Cole 1990).

Negative Heterograde Metalimnetic oxygen minimum Possible causes studied 1. Flow pattern of river into reservoir 2. Decomposition of suspended organic matter in the metalimnion

Conductivity a marker of inflow depth High conductivity values indicate depth of river inflow.

Expected Seston Values if hypothesis is not true

Conclusions The metalimnetic oxygen minimum is caused by a collection of organic material in the metalimnion. The presence of a metalimnetic oxygen minimum is not uncommon in reservoirs (Cole 1990).

Acknowledgments Raystown Field Station - Chuck Yohn Pfizer Corporation Emily Sowell, Huntingdon High School AJ Maurer, Juniata College Dr. Paula Martin, Env. Sci and Studies Dep. Juniata College Ken Culp, U.S. Army Corps of Engineers Dr. I. David Reingold, Chemistry Department, Juniata College Dr. Elaine Keithan, Biology Department, Bucknell University