By Meg Jarvis
I’m Meg Jarvis (they/them), and this past summer I surveyed the aquatic macroinvertebrate populations in Woodend Sanctuary’s recently restored pond. I attend university in Brighton, England, but I grew up just around the corner from Woodend. I went to camp there throughout my childhood and, when I aged out of camp, I started volunteering as a water quality monitor. That was my introduction to assessing stream health by sampling macroinvertebrates. I came to England to study ecology, where I’ve continued doing surveys and fieldwork. For my undergraduate dissertation, I knew I’d love to look at freshwater ecosystems, and that I was interested in working with Nature Forward. I hadn’t done research on ponds, and having seen the “before and after” of the restoration on the Woodend Pond and step pools, I thought it would make a great project.
Photo credit: Leslie Jarvis
Photo credit: Gregg Trilling
I discussed my initial ideas with my supervisor last May, and we agreed that it would be interesting to study how the pond’s food web has changed. Most assessments based on aquatic macroinvertebrate surveys examine the numbers and types of “sensitive” species living in a water body. This gives us an indication of water quality as some species cannot tolerate certain pollutants, levels of turbidity, etc. However, there are other ways to use invertebrate data to understand ecosystem health. For my project, I’m focusing on functional feeding groups (“FFGs”). Macroinvertebrates can be separated into guilds based on how and what they eat. For example, shredders break down larger organic matter like wood and leaves, while grazers feed on algae and other biofilms. A healthy ecosystem is characterized by certain proportions of these feeding groups, as well as an appropriately balanced ratio of predators to prey. It has been theorized that as a freshwater ecosystem changes physically, during restoration or due to a natural regime shift, FFGs will change in a manner that reflects its health and water quality. My aim is to see if this research holds up when applied to a pond environment. Bradley Simpson and Gregg Trilling, who are involved with Nature Forward’s Woodend restoration and community science work, provided prior and post restoration macroinvertebrate data. I will analyze this data set along with the data I collected over the summer to see how the food web has shifted.
Fieldwork is always my favorite part of any project. When I was younger, a classic Woodend camp activity was going “ponding” which involved a lot of mucking around in the mud and playing with nets. (We didn’t catch a whole lot.) Returning to the same pond as an adult was amazingly different. I observed more species richness post restoration and was able to find critters that I hadn’t come across before, even while monitoring streams, like phantom midges and water scorpions. Data from pre-restoration surveys typically represented around 10 family groups, usually heavily skewed towards aquatic worms and midges. I sampled the pond in June and September, and recorded 18 family groups in September. While midges were still a dominant family, species evenness was evident and other dominant groups emerged, like mayflies in June and backswimmers in September. A number of curious people stopped by while I was working, and it was lovely to meet them and explain what I was doing. I also engaged many young children who were delighted to look at the bugs in big containers of pond water. They reminded me of myself at their age. I hope that passion for the natural world stays with them. My project is still in its early stages; there is a lot of data processing and further research to do, but studying a site that is so familiar and working with the staff at Nature Forward have made it an incredibly interesting and enjoyable experience. It will be great to report my findings back to the organization that offered me so much in the way of nature education.
