Nature Notes: Trout habitat
By Sydney Weisinger
Jay C. Hormel Nature Center
With the addition of rainbow trout to Mower County’s Wolf Creek, local anglers will have a place closer to home to fish for trout. This is exciting and long awaited news for many, but how did Wolf Creek get picked and why is it a good location for trout?
Here at the Jay C. Hormel Nature Center, we teach Austin seventh graders all about water/ stream ecology. Something that we stress in our curriculum is how everything is connected, not only in the water itself but also actions that take place on land.
All the land that drains into a stream is called the stream’s watershed. The water and everything that depends on it is affected by what happens on the land in the watershed. That’s why when looking for good trout habitat we first have to look to the land in the watershed. James Fett, Watershed Technician at the Mower County Soil and Water Conservation District, stated, “that projects like Conservation Reserve Program (CRP), MNCREP and Reinvest in Minnesota (RIM) have permanently restored acres of wetland and prairies around Wolf Creek to help reduce sediment and nutrient concentrations.”
What we like to emphasize to the seventh graders about projects like these is that if these projects did not exist, sediment flowing into the stream from floods or heavy rainfall would cover the rocky bottom of the stream bed, destroying habitat for small aquatic animals that larger animals depend on.
Covering the rocky bottom also decreases ripples in the water, which decreases the amount of dissolved oxygen for fish to use. Sediment also makes the water cloudy and if the water continues to stay murky and cloudy, the temperature of the stream will increase.
During our seventh-grade class, we test Dobbins Creek for common nutrients like phosphorus and nitrogen as well as the pH levels. If there are too high concentrations of these nutrients, plant matter will grow very fast and it will eventually outgrow the demand of the food chain. With an increase of plant matter growth, usually algae, comes higher pH levels, which can be deadly to most aquatic life. As the plant matter starts to die and is decomposed by microorganisms, dissolved oxygen is consumed as well, leaving less oxygen in the water for aquatic life. Trout need a significant amount of dissolved oxygen to survive.
When we talk about dissolved oxygen, we also talk about water temperature because trout need fairly cold water temperatures of about 50-60 degrees Fahrenheit. According to Fett, “Wolf Creek is colder than many others in our area thanks to groundwater and spring outflow in Todd Park.”
Colder water temperatures also hold onto more dissolved oxygen, which in turn is able to support a larger population of trout.
In order for trout stocking and fishing to continue, a good habitat has to continue to be maintained. That is why programs like these are so important and have a great impact on the environment around us. Now more people are becoming connected to the land, their local watershed, and their waterways, thanks to the work that has been done to stock trout in Wolf Creek.
May at the Nature Center
Keep an eye on our social media and our website for updates on summer classes.
All Audubon Bird Hikes are for members only, please contact the Austin Audubon for more information.
• Saturday, May 16: Sola Fide, cancelled
• Wednesday, May 27: Volunteer Work Party, 3:30-5 p.m. Must RSVP. Watch for updates.
• Saturday, May 30: Canoe and kayak rental begins: Watch for updates; 1-2:20 p.m., bumble bee surveying event. Watch for updates