“The Scoop On Poop,” – Assessing nutrient loads, sources and habitat risks for endangered sockeye salmon in Cultus Lake, BC

Ongoing limnological and paleolimnological research has demonstrated Cultus Lake is undergoing cultural eutrophication, the enrichment of nitrogen and phosphorus from watershed sources. Resultant changes in water quality and biological productivity are impacting critical habitat for species at risk (Cultus sockeye salmon; Cultus pygmy sculpin). This project, supported in part by FSWP in Year 1, aims to critically assess the magnitude and sources of watershed nutrient loading to Cultus Lake via surface flows and groundwater. Only with this information can appropriate mitigation be applied for the protection of this sensitive salmonbearing watershed.

As this research is scheduled to occur over a two-year window, only preliminary results are available at this time. With the assistance of FSWP, we have begun to characterize intra-annual spatial and temporal patterns in surface hydrology and nutrient loadings that will underpin our nutrient flux model. To date, our research has identified unexpected nutrient hot-spots within the watershed, including tributaries originating from parkland catchments. We have developed a watershed groundwater flow model, which paired with wellwater nutrient sampling will allow us to assess sub-surface nutrient loading (both natural and polluted). Since the inception of the project, we have also expanded the focus to assess avian guano nutrient loading from the numerous gulls and Cackling Canada Geese as well as rainfall atmospheric deposition and will be assessing lake nutrient retention by measuring the N and P content of dated lake sediment cores.

Community Engagement:

Science makes the case and community makes it possible to engage decision-makers, First Nations and citizens for the benefit of Caring For Cultus Lake. Community is active at the CLASS table with monthly actions and outreach that expands from 20 people to 60 people to 120 and more. Stewardship interest is increasing and science translated into everyday language is being understood. Given the contact and information, everyone wants to help Cultus Lake. Work also includes peace-making circle-work to build relations with local governments, First Nations and also to help resolve conflict with those impacting Lake well-being. “Without intentional community building around the issue, we would not get very far,” said a Cultus resident, “ I get this now….”