Josh Scott Shaun Lacy John Robbins Owen Means

Sediment/Benthic Community

IntroductionObjectivesHypothesisMethodsResultsDiscussion

Outline

Landowner objective:Learning potential for small fishery

Suitable pond conditions?

Introduction

Determine composition of sediment% organic matter% water content

Estimate density and diversity of macroinvertebrates

Objectives

High water content equally throughout sediment

High organic mater in the top portion of the sediment

High concentrations of macroinvertebrates in the shallow areas

Hypothesis

Jones’ pond (15 miles southeast of Moscow)KB-Core

Triplicate samples at (2.7 m)Measured, weighed, dried, fried

Ekman dredgeTriplicate samples at (2.7 m)Sub-sampled, counted organisms

Methods

KB-Cores

Results

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.00.0

1.0

2.0

3.0

4.0

WaterOrganic

Content (%)

Sedi

men

t de

pth

(cm

)

Figure 1. Water and organic content of sediment samples taken at 2.7 m depth from Jones' pond Latah Co., Idaho 2008.

• Higher water content deeper in the sediment• Higher organic content deeper in the sediment

Ekman dredge

Results continued

Replicate 1 2 3 Mean (#/m^2) SD SE

Oligochaete 65244 32889 164444 87525.93 68549.72 39577.20

Table 1. Macroinvertebrate density from Ekman dredge sampling of Jones’ pond Latah Co., Idaho 2008.

Sediment4cm of sediment accumulation since pond was filledWater 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)

Discussion

Nutrient inputsDifficult to control nutrient inflow from

agricultureTry to reduce fertilizer use on and around property

Resample to determine sediment accumulation

Recommendations

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.

Literature cited

Questions?