Sediment/Benthic Community Josh Scott Shaun Lacy John Robbins Owen Means
Outline • Introduction • Objectives • Hypothesis • Methods • Results • Discussion
Introduction Landowner objective: • Learning potential for small fishery • Suitable pond conditions?
Objectives • Determine composition of sediment • % organic matter • % water content • Estimate density and diversity of macroinvertebrates
Hypothesis • High water content equally throughout sediment • High organic mater in the top portion of the sediment • High concentrations of macroinvertebrates in the shallow areas
Methods Jones’ pond (15 miles southeast of Moscow) • KB-Core • Triplicate samples at (2.7 m) • Measured, weighed, dried, fried • Ekman dredge • Triplicate samples at (2.7 m) • Sub-sampled, counted organisms
Results KB-Cores • Higher water content deeper in the sediment • Higher organic content deeper in the sediment
Results continued Ekman dredge Table 1. Macroinvertebrate density from Ekman dredge sampling of Jones’ pond Latah Co., Idaho 2008.
Discussion Sediment • 4cm of sediment accumulation since pond was filled • Water content higher at bottom of sediment • Opposite of normal results Macroinvertebrate • Only oligochaetes were found • 87,526/m2 (SE 39,577) • EPA rating in Detroit River 5,000/m2 (Ciborowski 2008) • Farm ponds in Philippines 0-32,000/m2 • Density positively correlated with high nutrients and/or organic matter (Simpson et al. 2004)
Recommendations • Nutrient inputs • Difficult to control nutrient inflow from agriculture • Try to reduce fertilizer use on and around property • Resample to determine sediment accumulation
Literature cited • Ciborowski, J. 2008. [Online] Detroit River-Western Lake Erie Basin Indicator Project. Available: http://www.epa.gov/med/grosseile_site/indicators/oligochaetes.html • Simpson, I.C., Roger, P.A., Oficial, R., and Grant, I.F. 2004. Density and composition of aquatic oligochaete populations in different farmers’ ricefields. Biology and Fertility of Soils 16: 34-40.