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Perron, M.A.C., C. Charette, A. Francis, C. Holden, M. Moyle, J. Boyle, J. Franceschini, M.B.C. Hickey, A. Nurse, J.J. Ridal, K. Shuji, M.J.S. Windle, M. Wylie-Arbic, and L.J. McGaughey. 2024. Revisiting the influence of top-down and bottom-up pressures on Wa hia hé:ta (yellow perch Perca flavescens Mitchill, 1814) population dynamics in Kaniatarowanenneh (the Upper St. Lawrence River): implications for collaborative research. Canadian Journal of Fisheries and Aquatic Sciences 81:796–809.
The Wa hia hé:ta, or yellow perch Perca flavescens, is an important species in the Upper St. Lawrence River. Ecologically, it is a vital component of the food web serving as both a food source for many species including popular game fishes and a predator of others such as zooplankton and smaller fish species. It also holds significant cultural and economic importance, sustaining the livelihoods of subsistence fishers and the many people associated with its commercial and recreational fisheries. It is abundant, iconic, and long revered in this part of the world.
Unfortunately, fishers have observed a decline in the number and size of yellow perch being caught in the Upper St. Lawrence River and other areas of the Great Lakes. As a result, it was recognized by the local communities, both Indigenous and non-Indigenous, as a species of concern. Prompted by these concerns and its role as an ecosystem health indicator, the St. Lawrence River Institute in partnership with the Mohawk Council of Akwesasne Environment Program initiated a yellow perch study as part of their larger Great River Rapport project.
In 2020, Dr. Mary Ann Perron, Scientific Lead for the Great River Rapport and Liber Ero Postdoctoral Fellow at the St. Lawrence River Institute, began working on this project and a new study to identify factors influencing yellow perch abundance over time. This study utilized historical data to determine if “top-down” processes such as predation of yellow perch by other fish, “bottom-up” processes such as the availability of nutrients in the system, or a combination of both were driving observed shifts in yellow perch abundance. The mission goes beyond the science, though, as Dr. Perron notes. “The main goal of the project is to communicate the science back to the community in an accessible way to mobilize knowledge but also to be open to feedback to improve our understanding of the river and its People.”
Photo Credit: Stephany Hildebrand, St. Lawrence River Institute
This study, which was conducted as one component of the larger Great River Rapport project, was guided by what is known as a “Two-Row Wampum” approach. As explained by Dr. Perron, wampum belts have long been used by Haudenosaunee to narrate and record history, traditions and laws. The “Two-Row Wampum” belt was initially created as a treaty between the Dutch and Haudenosaunee and graphically represents two vessels (Dutch ships and Haudenosaunee canoes) traveling side by side each other and keeping to their lane. Abraham Francis, who is an Akwesasronon, PhD Candidate at Clarkson University, and co-author on the paper, explains, “the separation symbolizes mutual respect for each party’s autonomy in perpetuity.” Dr. Perron and her colleagues took steps to follow this approach by bringing Akwesasronon community members and scientific partners into the research process. The aim is for the research to reflect and be informed by Akwesasronon perspectives, while also respecting Indigenous sovereignty and autonomy.
By utilizing historical data, Dr. Perron and her team found that changes in the yellow perch population were associated with both the amount of predators and nutrients in the Upper St Lawrence River, although in different ways. Even more interestingly, they found that although the number and size of yellow perch have declined, it was likely the result of efforts reducing the anthropogenic input of phosphorus into the system. So, what may at first appear to be something negative may instead reveal a return to conditions that existed prior to nutrient pollution altering the system. Their study illustrates the importance of long-term datasets that allow current observations and trends to be put into proper context and help better inform decisions moving forward. “I think the take home message from this study,” stated Dr. Perron, “is that the river is constantly changing, and we must adapt our ways of living to support a sustainable future.”
So much of this study, and the resulting paper, focuses on connection and collaboration – with the community, with partners, and with others intrinsically tied to the resource. Dr. Perron touches on the importance of connecting with the local people, “Having open discussions with people who have lived in your area of study helps ground the scientific process, in most cases the people living on the lands and waters will know a lot more than you do about the specific ecosystems. There is immense value to forming meaningful relationships with community members, whether it be to help validate your findings based on their observations through time or provide feedback on certain results. Keeping those doors open for continuous learning as information becomes available is the fundamentals of science, and the community can help scientists do that.” This continued into the writing process, as the team organized a 3-day writing retreat along the St. Lawrence River to discuss preliminary results and different perspectives to be incorporated into the paper and other study communications. In return, the Great Rapport then provided a platform for the dissemination of information back to the community through infographics, social media campaigns, and public presentations, some of which we list below.
Photo Credit: Stephany Hildebrand, St. Lawrence River Institute
As it goes with science, there is still much work to be done. Yellow perch is only one of 35 ecological health indicators identified by the Great River Rapport. Dr. Perron recently led a similar effort for northern pike Esox lucius and has no plans to stop there. When asked about her role in the future of the Great River Rapport, she said, “I am planning to continue nurturing these relationships as I truly believe in the impact that this project can have. I am hopeful I can continue to be involved in this project for the rest of my days because I care about these people and I feel like my work is appreciated and valued.”
Big things can happen when we commit to listening and working together for our collective future.
That’s a lesson worth sharing.
The full manuscript can be found and downloaded here (open access):
doi.org/10.1139/cjfas-2023-0130
Great River Rapport
https://riverrapport.ca/
Link to public presentation about the yellow perch findings:
https://www.youtube.com/watch?v=Dl2j9gq1XkQ
Links to the social media campaign for the yellow perch:
St. Lawrence River Institute (@riverinstitutec) • Instagram photos and videos
St. Lawrence River Institute (@riverinstitutec) • Instagram photos and videos
St. Lawrence River Institute (@riverinstitutec) • Instagram photos and videos
St. Lawrence River Institute (@riverinstitutec) • Instagram photos and videos
St. Lawrence River Institute (@riverinstitutec) • Instagram photos and videos
St. Lawrence River Institute (@riverinstitutec) • Instagram photos and videos
I grew up in a very small town in northcentral Ontario. My dad is a commercial bait harvester and runs a bait shop. I always loved to help my dad out and grew up trapping minnows with him and selling minnows at the small bait shop we ran from the house. I have counted minnows for as long as I remember! This work embedded a deep love for nature and provided me with a fundamental understanding of freshwater ecology that is still the basis for my work today.
I went on to complete my BSc and PhD, as a first-generation student to complete post-secondary education in my family. This was not easy at the time as I had to work hard to save money and get scholarships to fund my education. However, I was passionate about the environment and was persistent enough to succeed with the help of various mentors and supporters along the way who I am deeply grateful to.
My formal training is in freshwater ecology with specializations in wetland ecosystems. I have worked most of my career with plants and dragonflies but the opportunity to shift my focus presented itself in 2020 when I accepted a postdoctoral position at the River Institute working on the Great River Rapport. The yellow perch indicator was the first we wanted to complete given its huge importance to the area and to the public. Perch fishing is a way of life for local communities and they wanted answers regarding recent declines in their populations. So although, this would be the first time I formally study fish I had a solid background to understand their biology through a lifetime of observation of working with my dad, fishing on the lake I grew up on, and my academic studies. This work has been very interesting and I am currently finishing up a similar investigation on population trends of northern pike in the river.