Using Benthic Macroinvertebrates to Determine Water Quality

1. Using Benthic Macroinvertebrates to Determine Water Quality Presented by the Blue River Watershed Association brwa.net

2. What are Benthic Macroinvertebrates (BMIs)? • animals with no backbones • are visible with the naked eye • live at the bottom of shallow waterways

3. Examples of BMIs

4. Why Use Macroinvertebrates to Determine Water Quality? • important links in the food chain • permanent residents of the stream • can move only short distances • susceptible to any pollutants in the water

6. Easiest to identify: Snails (class Gastropoda) Clams and Mussels (class Pelecypoda) Identifying BMIs

7. no head, legs, wings, or exoskeletons Characteristics of Worms and Leeches

8. Exoskeleton Head has 2 compound eyes 2 pairs of antennae 3 pairs of mouth parts Swimmerets on the abdomen Scud Sowbug Crayfish Characteristics of Crustaceans

9. Head has compound eyes, antennae, and mouth parts Thorax has 3 pairs of legs and wings attached Abdomen is the longest region of insect’s body Characteristics of Insects

10. Incomplete Metamorphosis Complete Metamorphosis Aquatic Insect Life Cycle

11. Categories of Pollution Tolerance

12. Pollution Sensitive

13. Somewhat Sensitive

14. Pollution Tolerant

15. Can collect good sample all at once Easy to make Can use in deeper water than others Requires 2 people to hold net down in current A bit difficult to transfer sample into holding container How to Use a Kick Net

16. Only requires 1 person to hold in current Easier to transfer sample into holding container Too small to collect 3 x 3 sample all at once Some BMIs may drift over top of net in deeper water How to Use a D-Net