Macroinvertebrates

7/22/24

Ecological Conditions Could Not be Determined at this Time

Save Our Streams Multimetric Index Score: 8

Blackflies

Blackflies, making up 55% of the sample, were by far the most abundant macroinvertebrates I saw. I was able to count 28, but I know that there were more.

Netspinners

I counted 8 netspinners which made up 15.7% of the sample.

Caddisflies

I counted 8 caddisflies, meaning that they made up 15.7% of my sample. I only put two caddisflies in my ice cube tray, however, because I didn't want to break their shells while rubbing them off the rocks (I'm scarred for life from accidentally stepping on big garden snails in New Mexico). After my rock-rubbing time was up, I went back and counted the caddisflies that I had left. One of the two caddisflies I collected in the ice cube tray had no shell while the other (which I'm not actually sure is a caddisfly) was just using a piece of waterlogged stalk from some plant. All the ones I counted on the rocks had made shells out of stones (image located at bottom of page).

Mayflies

I found three mayflies in all. They were all quite small. The biggest one I caught was the one in the bottom right corner. One of its tails got caught and fell off while I was trying to transfer it to the ice cube tray. The mayflies made up 3.9% of my sample.

(Stoneflies)?

I found two two-tailed tiny insects that I called stoneflies. These made up 3.9% of my sample. Both of these "stoneflies" were really small, unlike all the others I've seen. They also both kept their tails in an upward-pointed position.

Clam

I found a single tiny clam. It made up almost 2% of my sample.

(True Fly)?

When I found this in my net I didn't think that it was aquatic but I decided to put it into my collection bin just in case. I never found it in the debris, however, so I wasn't able to get a picture. It was a slightly see-through white with a disturbingly tiny orangish head and was soft like a caterpillar. Its rear was attached to a pine needle but I didn't look closely enough to see how it was holding on. (the image was drawn from memory so may not be fully accurate)

Honorable mention: I found a small lunged snail shell in my net. There was no snail in it, though.

Water Sampling Results

Temperature: 59.5°F, 15.3°C

pH: 6.5

Average Conductivity: 408 µS/cm

I drew a close-up of the biggest netspinner I caught.

This is my drawing of the invertebrate I thought was a true fly. I think its head was smaller in real life.

Land Use Data

Reflection

In an attempt to discourage more mosquitoes, I heavily applied all three types of insect repellent I could find. There were still swarms of mosquitoes around me, but this time only around 15 actually tried to steal my blood. It was significantly more pleasant with less mosquitoes. While 51 macroinvertebrates is far from the goal of 200, it was more than I expected to find. Earlier in the year I had tried to find macroinvertebrates in a similar connected stream and didn't find anything! The most trouble I had while at the brook today was sifting through all the debris in my net to find the invertebrates. In my first collection, I got around a pound of sand in addition to a bunch of waterlogged wood pieces. It took a while to dig through everything and I know I couldn't have found every little macroinvertebrate. For example, I know that the true fly larva was lost in the debris. Today the brook looked much like it did yesterday with its silty bottom, abundant frogs, and little dapples of sunlight. I felt more relaxed than yesterday because it was the second day going out, I had proper writing utensils, and I didn't have to deal with as many mosquitoes. I'm happy that I finally got pictures of the frogs so that I could ID them! I also saw a cool-looking caterpillar that I'd never seen before.