Since 2007, WLI has sampled the lake monthly taking both water samples and water sensor data at two points in the lake. One sample point is near the shallower south end of the lake and another is at the deepest part near the north end of the lake. Below are summary graphs using yearly average data from both sampling locations in June, July, and August. Each graph shows yearly average and error bars representing standard error of the yearly average. Overall, due to efforts from the community of Whitefish and WLI the lake remains relatively low in nutrients and high in water clarity. The lake does show an increasing trend in chlorophyll-a, one of the pigments found in algae, this could be due to multiple factors that WLI are currently investigating. To find out more about lake health click on the water quality variables below.
Water Clarity (Secchi)
Water clarity is an important variable for both water health and aesthetic and economic value of Whitefish Lake. Secchi is measured by lowering a black and white disk into the water until it disappears, that depth is then marked as the Secchi depth. Thus, the best water clarity creates the deepest Secchi depths. Whitefish Lake has maintained consistent high water clarity and does not have a strong trend of decreasing water clarity. The long-term average Secchi depth is 23 ft.
Surface Temperature
There is a slight increasing trend in Whitefish Lake surface temperature. The long-term average surface temperature is 62 degrees. Higher lake surface temperatures can lead to more algal production.
Total Nitrogen
Nitrogen is a nutrient used in algal production and high levels of nitrogen can often result in algal blooms. Increases in nutrients such as nitrogen are often due to human influence. Whitefish Lake has no trend in total nitrogen, recent years have been below the long-term average of 79.05 ug/L. Overall, Whitefish Lake has low nitrogen levels.
Total Phosphorus
Phosphorus is a nutrient used in algal production and can often come from human driven sources such as septic leachate, fertilizer, or detergents. Whitefish Lake has no trend in total phosphorus, although some monthly values have been above the long-term summer average. The long-term average for phosphorus in Whitefish Lake is 3.59 ug/L which is considered low.
Chlorophyll
Chlorophyll is a pigment within algae, and it is used as a proxy to measure lake algae production. Whitefish Lake has an increasing trend in chlorophyll at both sites, indicating that lake algae levels have increased throughout the last decade. This increase in chlorophyll despite no trend in increasing nutrients could be due to longer and hotter summers, or spring peaks in nutrients that are not reflected in this summer data. WLI is currently working to expand our sampling season to better understand seasonal nutrient trends in Whitefish Lake. The long-term average for chlorophyll in Whitefish Lake is 1.45 ug/L. In the graph below the deep sampling site is indicated in blue, and the shallow sampling site is indicated in red.
Deep Lake Temperature
This graph shows the water temperature at the bottom of the lake. This is the coldest area of the lake and important fish habitat. It is important to monitor this area as rising temperatures may endanger this critical habitat. In the graph below the deep sampling site is indicated in blue, and the shallow sampling site is indicated in red.
Deep DO
Dissolved oxygen at the bottom of the lake is important for fish habitat. In many lakes due to longer and warmer summers in deep waters, dissolved oxygen is decreasing. In Whitefish Lake dissolved oxygen levels are remaining high. For both sites combined, the summer average of dissolved oxygen saturation is 84%. In the graph below the deep sampling site is indicated in blue, and the shallow sampling site is indicated in red.
