What can the canary in the coal mine tell us?
August 27, 2019 4:58 PM   Subscribe

Benthic (meaning “bottom-dwelling”) macroinvertebrates are small aquatic animals and the aquatic larval stages of insects. From highly sensitive stoneflies to those much more tolerant of pollution, like hydropsychid caddisflies, what bugs you find in your local streams tells you how clean the water is as they serve as bioindicators.

Although these techniques were developed by stream ecologists, anybody can now get trained to volunteer to help monitor their local streams with macroinvertebrate bioindicators through programs like Save Our Streams or Adopt-A-Stream: GA, IL, IN, MI, NC, SC, TN
posted by hydropsyche (12 comments total) 21 users marked this as a favorite
I love citizen science!
posted by Wretch729 at 5:13 PM on August 27, 2019 [1 favorite]

Be careful hydropsyche, your babies (larvae) are highly sensitive to pollution. Though you and your winged adult caddis bros may be cool with it.

Turning over wet rocks in the stream helps us fly fishers know what is hatching and what to be matching to catch a trout on an artificial fly.
posted by artdrectr at 5:33 PM on August 27, 2019 [3 favorites]

Should we have an eponsyterical challenge then?

I love me some freshwater larvae but one of the biggest natural scares of my life was a surprise face-to-face encounter with a cigar-sized juvenile... something in the streams of Northern CA. At the time I thought it was a dragonfly but I’m not currently seeing any examples so huge and so fleshy.
posted by SaltySalticid at 6:13 PM on August 27, 2019

I was a TA for a course where I got to demonstrate all of the field methods for stream ecology because my professor had a lasting injury. Bioassessment using aquatic invertebrates was one of the components and was so cool for me to teach and to learn about (I'm more of a birds/plants person). The professor was always telling me how obvious it was that I loved doing that kind of field work and it showed through so much that it helped the students develop enthusiasm for it as well (a lot of them were more on the social science side of Environmental Studies). There really are few memories from my schooling that are as happy as the ones where I got to tromp through streams and look for critters.
posted by primalux at 7:56 PM on August 27, 2019 [1 favorite]

What can the canary in the coal mine tell us?

When to take a deep breath: Arrival (2016).
posted by cenoxo at 8:06 PM on August 27, 2019

cigar-sized juvenile... something

Maybe a beetle? Some aquatic beetle larvae are huge.

Our education group does a portable pond activity where we make a 1” deep pond with a plastic drop cloth and have a lot of aquatic insects and stuff in it so kids can see them easily.
posted by snofoam at 11:23 PM on August 27, 2019

Or an eel.
posted by artdrectr at 11:38 PM on August 27, 2019

Be careful hydropsyche, your babies (larvae) are highly sensitive to pollution.

No, hydropsychid caddisfly larvae are not sensitive to pollution. We are the least sensitive family of caddisflies. We live in very urban streams, capturing gross organic matter in our nets. We are robust survivors, not like those sensitive Limnophilidae. Those guys can't handle even a little bit of urban runoff or leaky sewage pipes.
posted by hydropsyche at 3:20 AM on August 28, 2019 [2 favorites]

cigar-sized juvenile... something

Most likely a helgrammite, a juvenile dobsonfly.
posted by hydropsyche at 3:22 AM on August 28, 2019 [1 favorite]

We are robust survivors, not like those sensitive Limnophilidae.

I never realized how much I needed macroinvertebrate trash-talking, but here we are.
posted by pemberkins at 3:34 AM on August 28, 2019 [3 favorites]

I love citizen science!

Yes. Especially in schools. Learn science by doing science.
posted by pracowity at 4:19 AM on August 28, 2019

I liked the bioindicators article a lot (though the author was a bit too optimistic about the prospect of using ecological indicators to regulate irrigation withdrawals—that can barely happen even with ESA listed species of significant cultural importance). If you can find the right species to track, you can monitor ecological conditions across a large geographical scale relatively easily.

I don’t work with benthic species much at all, but my favorite research about them is the startlingly long distance they travel through the saturated alluvial aquifer away from the river. At least for some species, their environment is the entire connected shallow aquifer (ie the subsurface area with hyporheic flows etc), not just the surface water in the stream.
posted by Dip Flash at 6:10 AM on August 28, 2019 [1 favorite]

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