Benthic Analysis: Mr. Ingle’s Pond

1. Benthic Analysis: Mr. Ingle’s Pond X Group Tarah Johnson McClure Tosch Stephen Wells Lance Keller

2. Overview • Objectives • Study Area • Materials & Methods • Results • Conclusions • Summary

3. Objectives Shallow Water vs. Deep Water • Sediment Type • Organic material • Benthic invertebrate population

4. Study Area • Deep: 9’2” • Shallow: 3’ 5”

5. Methods • Assessment was split into two parts: • Benthic sampling for macro invertebrates • Eckman Dredge • 15 cm x 15 cm • Weight sampling for sediment loading and organic concentration • KB corer • 2 inches in diameter

6. Methods • Both assessments were taken in triplicate totaling 6 samples each • Deep • 3 Eckman Dredge samples • 3 Core samples • Shallow • 3 Eckman Dredge samples • 3 Core samples

7. Methods: Eckman Samples • Sieved on site • Biota preserved with formalin • Transported to lab for analysis

8. Methods: Eckman Samples • Filtered to wash off formalin • 80 micrometer (μm) sieve • Large samples • Sub-sampled when needed • Observed under dissecting scope • Counted and identified to family • T-test and an ANOVA • Difference in count and composition

9. Methods: Core Samples • Core samples were sectioned on site • 2cm sub-sample to 10cm • Wet weight • Crucible weight (zeroed out) • Crucible + sediment sample

10. Methods: Core Samples • Oven Dry Weight • 24 hours at 150° C • Organic Weight • Furnace: 3 hours at 500° C • T-test and an ANOVA • difference in composition between shallow and deep samples.

11. Results: Profiles

12. Results: Eckman Samples

13. Greater Diversity in shallow samples Shallow samples were more even distributed Shallow samples had more taxa Results: Eckman Samples

14. Results: Eckman Samples • Major Taxa Found - Chaoboridae - Chironomus • Minor Taxa Found - Ceratopogonidae - Oligochaeta

15. Results: Core Samples

16. Results: Core Samples

17. Results: Core Samples • There was no difference in moisture content • There was a difference in percent organic • The sediment is mainly composed of silt

18. Conclusions • Fish feed on Chaoboridae and Chironomus larvae (Sweetman 2006). • Chironomus larvae suggest highly eutrophic pond (Saether 1979) • Chaoboridae larvae specifically Chaoborus migrate vertically to avoid predation (Sweetman 2006).

19. Conclusions • The percent water content suggests a silt/clay sediment • Dr. McDaniel concluded the sediment was mostly silt • The difference in percent organic might be from differences in Chaoboridae numbers.

20. Summary • The high Chaoboridae and Chironomus populations are good fish food but might not be available to eat. • There is a difference in organic soil content between deep and shallow probably due to Chaoboridae pop. • There was no difference in sediment loads between the shallow and deep end of the lake.

21. Acknowledgments • Mr. Ingle • Picture Credits • iodeweb5.vliz.be/.../AndersonBook/SampEquip.htm • Dr. Wilhelm • Other Credits • X Group Bathometric Group • X Group Light and Temperature Profiles

22. References • Jon N. Sweetman, a, and John P. SmolaReconstructing fish populations using Chaoborus (Diptera: Chaoboridae) remains – a review Paleoecological Environmental Assessment and Research Laboratory (PEARL), Department of Biology, Queen's University, Kingston, Ont., Canada K7L 3N6 • Saether, O.A. 1979. Chironomid communities as water quality indicators. – Holarct Ecol. 2: 65-74

23. Questions?