Josh Scott Shaun Lacy John Robbins Owen Means Sediment/Benthic Community
Feb 23, 2016
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?