If there was one thing I could suggest you do with your kids this summer, catching aquaticÂ macroinvertebratesÂ would be near the top of my list. Nerdy I know, but in every Nature Center I’ve worked at, this activity has been the favorite of Â parents and children alike (well, most parents). It involves water, mud, nets andÂ unearthlyÂ looking creatures seldom noticed by humankind.
What’s an aquatic macroinvertebrate you ask? It’s a small water dwellingÂ invertebrate, big enough to be seenÂ withoutÂ a microscope. Many of these critters are actuallyÂ juvenileÂ forms of well known adult insects. For example, does the picture to the right look familiar… it’s actually a dragonfly stuck in its awkward teenage years.
WHAT TO GATHER:
- Net for each child. This can be as simple as a aquarium net (ideally a long handled one) or as fancy as a ‘real’ aquatic net.
- Large shallow plastic tote. Something to dump the contents of your net into so that you can sift through it. We’ve used a variety of containers, whatever you use, just make sure the water/plant/sludge mixture is only about an inch or two deep so that you can look through it easier.
- Small containers or plasticÂ petri dishes. Something you can transfer critters into so that you can observe and ID them.
- Identification key. This is a goodÂ macroinvertebrate key or there is an interactive online version, I use this key, it’s made for Utah but it’s also applicable to surrounding areas.
- Forceps. You can also use a stick or your hands to pick out critters. If your kids use theÂ forcepsÂ you might want to teach them the proper technique first so that your critters don’t end up pinched in half.
WHAT TO DO:
- Find aÂ wetland. ItÂ doesn’tÂ even need to be a fancy wetland, we often head out to the canal behind our house. Find a pond, stream, river, creek, lake, etc.
- Locate a place long the water where there is some vegetation.Â Most critters hang out at the base of plants or in that top layer of mud near plants.
- Put a little bit of clean water in your plastic tote.
- Get out your net and start scooping. You don’t want to fill your net with mud but you might want to scoop the very top layer. Swish your net around near the base of the plants, get some of that plant matter in your net, but again, don’t fill it with plant matter.
- Dump the contents of the net into your plastic tote.
- Put some water in your small containers or petri dishes.
- Grab a stick, yourÂ forcepsÂ or use your fingers and look though the material you collected.
- Pull out anything that looks interesting or that you see moving and put it in the petri dishes.Â Note: Unless you want to see the food chain in action you might want to keepÂ differentÂ speciesÂ separated. Last week we put a dragonfly nymph and a baby crayfish together, a few minutes later the only thing left of the crayfish was the head.
- Dump the leftover contents of the tote back into the water and repeat steps 1-8 until you have enough critters to identify.
- Get out the identification key and ID away.
A few pictures from our recent macroinvertebrate collecting adventure.
Your kids will love it.