Please join us in welcoming Cheryl Reyes to the blog this week! Cheryl, a recent graduate from the University of Waterloo, is currently working as a Conservation Technician with the Nature Conservancy of Canada. For more about Cheryl, see the end of this post.
Although I have been working at a land conservancy monitoring alvar and tallgrass prairie ecosystems, and managing invasive plant species for the last few months, one thing remains the same: when I stumble upon a river, wetland or small creek I always wonder, “what kind of benthic invertebrates are living there”.
This recurring thought stems from my first true interest in the field of ecology: water and benthic macro-invertebrate sampling.
Sampling benthics often means going to very beautiful places sometimes in the middle of nowhere.
Benthic macro-invertebrates are aquatic insects that live at the bottom of water bodies, such as aquatic worms, leeches, beetles and flies. They do not have a backbone and are large enough to see with the naked eye, but when you put them under a microscope for further analysis they look much more impressive! These little creatures can reveal a lot about the health of a freshwater system because they are an important part of the aquatic food chain and respond quickly to stressors such as pollution. For this reason, they are referred to as “indicator species”.
One of my favourite photos of a mayfly larva, from the Ephemeridae family. You can distinguish mayfly larvae by their side gills and three (sometimes two) tails. This one has tusks on its head!
I was first got introduced to benthics during a field ecology course at the University of Waterloo. Since then I have collected and identified benthic invertebrates for many organizations, most recently during my role as a Monitoring Technician at the Crowe Valley Conservation Authority. Crowe Valley runs a benthic monitoring program within their watershed to monitor water quality. Sampling sites are located throughout the watershed and benthics sampling follows the Ontario Stream Assessment Protocol (OSAP) and the Ontario Benthos Biomonitoring Network (OBBN).
Sampling for benthics is fun and easy to do. Dressed in waders, with a net in hand, two people get into a stream and move between the banks while kicking up the substrate on the bottom. The net is swept back and forth through the water to collect benthics. The continuous sweeping motion is important to prevent any benthics collected from swimming out of the net. After three minutes of kicking and sweeping, the contents of the net are emptied into a bucket and hauled back to the lab/office for identification.
Me sampling for benthics. This was a great day because it was the only day of the entire field season I didn’t have to cover my face to protect myself from the bugs.
However, as is the case with most field work, sampling for benthics is not always the most glamorous job. Sometimes you get so into the Footloose-esque substrate kicking that you forget to watch your footing and trip over some large rocks, a log, or if you’re lucky (or unlucky) a large snapping turtle. Other times you wish the three minutes of kicking would be over because you can feel the sweat pooling in your waders. Much of the time you can’t see a darn thing because you have your bug jacket on to prevent all the mosquitos, black flies and deer flies from devouring your flesh. And when you look at the contents of your net, it’s hard not to wonder, “Are there actually any bugs in this giant pile of mud, rocks and leaf litter??”. But the most draining thing is hauling your large buckets and equipment to the site, then hiking the full buckets out from isolated locations after a long day’s work…then enduring the frequently lengthy drive back to home base.
My work station for 8 months at the Crowe Valley office. During my undergraduate, I was used to identifying bugs in a laboratory setting. But while working at Crowe Valley, I had to use ingenuity to set up a functional work station!
Studying benthics is definitely its own realm of ecology, with its own fieldwork quirks, and I love it. Why? The reward is always great. When you find benthics in your bucket and put them under a microscope, you get a sense of how complex aquatic ecosystems really are. I could spent hours looking at all the different taxa and the features that make them truly unique specimens. And because they tell you about water quality, studying them allows you to begin to appreciate how important water is in our everyday lives, and why it’s essential that our ever-developing society conserves and protects freshwater ecosystems.
So next time you see a body of water, remember that there is a little universe lurking in the depths of the substrate. All you need to discover it is some waterproof footwear, a container and a net.
Caddisfly larva from the Hydropsychidae family in the palm of my hand. This taxa, as a member of the Hydropsychidae family, spins nets that help it catch food such as algae, leaf litter and smaller benthic invertebrates.
Cheryl Reyes is a graduate of the School of Environment, Resources and Sustainability at the University of Waterloo. Her undergraduate research focused on assessing the benthic invertebrate communities of restored streams in urban areas. She is currently working as a Conservation Technician for the Nature Conservancy of Canada.
Dispatches from the Field 
Pingback: We’re back! | Dispatches from the Field