Insects are indicators of water quality. They are often overlooked for their small size and it takes a curious pond-dipping, fly-fishing expedition or an entomologist to remind us of how these little creepers play an important role in our aquatic environments. Thankfully we had two out of three of these reminders in the first-ever BCWF WEP Aquatic Invertebrate Workshop at the Silverdale Wetland in Mission, BC this past weekend.
Karen Needham, curator at the Spencer Entomological Museum and lecturer to the department of Zoology at the University of British Columbia, started off the workshop with an engaging presentation on the different types of aquatic insects that might be found in our region. I can safely say that her talk could make nearly anyone want to change professions (and become an entomologist!). Karen’s use of such fun descriptors as Dragonfly “wheels of love” and their competitive “sperm scooping”, as well as explanations of the 90 minute lifespan of the Ephemeroptera (Mayfly), the magical casings created by Caddisflies, and the shiny air bubble carried into the depths of a pond by Water Beetles gave each insect real character. We all learned many identification tips, including how to differentiate between immature Damselflies and the similar looking Mayfly (their tails, gills, and swimming style give them away!) and how to define a “true bug” (Hemiptera have a hardened half to their front wing, no gills and a piercing & sucking mouth part). Karen brought some cases of aquatic insects with her from the museum with specimens for us to see up close during our break.
Tim Howay, a past participant of the Mission Wetlandkeepers course (2012), Environmental Consultant and experienced Mosquito Taxonomist, took the group through the process of sampling for invertebrates using the CABIN (Canadian Aquatic Biomonitoring Network) protocol. The impetus for the workshop, Tim had sampled for insects at Silverdale Wetland soon after the Wetlandkeepers course. What he found was a startlingly unfamilliar type of Stonefly, an insect that might possibly be previously undiscovered. This exciting news shouldn’t come as too much of a surprise, however, as Karen made note in her talk of the sheer quantity of unnamed insects around the world: in British Columbia it is imagined that we still have yet to discover 25% of our insect population! Tim has been working with Karen Needham on this case of the unique Stonefly and plans to sample every two weeks around the Silverdale wetland to gather examples of the different life stages to better identify this insect.
After our classroom presentations and discussions, our class headed out into the wetland, divided into two sampling groups: one following the CABIN protocol with Tim in a stream, the other sampling with Karen in the still waters. Everyone had the opportunity to try both areas and methods as groups rotated and gathered fresh data.
In the stream we identified the specifics of the site, including such information as the water temperature, Ph, turbidity, the size and composition of the stream bed, the stream length and depth. The procedure for collecting insects in this flowing water was a physically demanding 3-minute walk with a kick net through the flowing water. After sampling for insects we kept and labelled samples of the contents of our kick net.
In the still water wetland, we used a variety of insect trapping nets and tools on both the riparian land and in the water, including the “pooter” where we sucked through a tube to capture flying insects that we would knock from trees and shrubs. After both groups had been through this activity, two basins one from a larger wetland and another from a separate and more shallow flooded area contained a real variety of larva and water beetles: Dragonflies, Damselflies, Mayflies, Caddisflies in their cool Reed Canary Grass casings, several types of diving beetles and side swimmers. One group even found a large egg mass in the waters while sampling that belonged to a Northwestern Salamander. We all were caught bug gazing throughout this activity and attracted many passers-by who wanted to participate.
When the groups came together at the end of the workshop we were all lucky enough to view this “new” Stonefly under a microscope on site. One of the groups sampling with Tim collected another 3 specimens (which brings us to 5!), so we were fortunate to view its striking colours and patterns up close. After the sheer success and great interest in this workshop, plans to include more activities based on invertebrate sampling and identification in other workshops is being seriously considered. Afterall, who doesn’t love exploring the miniature aquatic environments of a wetland?
The BCWF Wetland Education Program would like to thank Habitat Conservation Trust Foundation for financial support, Rachel Drennan & Natashia Cox of the Fraser Valley Watersheds Coalition for in kind support with the venue and communications, our wonderful instructors Tim Howay and Karen Needham for inspiring us all, and all the participants (some from as far away as Kamloops) for their commitment to wetland conservation!
For more photographs taken at this workshop, see our Flickr set.