Beaver Pond vs Stream Temperatures Study

When the Friends of the North Pikes Creek Wetlands organization learned that the Superior Rivers Watershed Association (SRWA) – then the Bad River Watershed Association – was expanding its water quality testing footprint, we welcomed the opportunity to monitor “our” river. North Pikes Creek is a Class I trout stream that begins in the Town of Russell on the Bayfield peninsula, joins Pikes Creek, and empties into Lake Superior’s Chequamegon Bay. Having been advised by local trout fishermen that North Pikes Creek/Pikes Creek was one of the last unsilted streams flowing into the Bay, we were curious to learn more about the health of this riverine system.

We began water quality testing in July of 2016, testing at three sites in the upper watershed monthly throughout the year. A few years later, we added two additional testing sites – one located in the middle of the streams’ reach, and the other near the mouth. Our volunteer crew was now sampling water chemical properties and temperatures from the head of the six-mile-long stream to the mouth.
We sampled monthly year-round, and noticed a distinct pattern in the water temperatures of the creek versus a large beaver pond. The beaver pond temperatures were warmer in the winter months, and cooler in the summer months, than the creek temperatures both above and below the pond.

SRWA subsequently loaned us the use of their HOBO water temperature data loggers, which enabled us to collect accurate measurements of the creek and beaver pond temperatures daily for a year. We suffered a setback when some thoughtless person stole the logging instruments, which necessitated restarting the project anew the following year. We now have accurate data comparing the beaver pond and stream temperatures at North Pikes Creek for an entire year. The preliminary conclusions from our initial manual temperature readings were validated with the more precise year-round data obtained from the temperature data loggers. The water temperature in the beaver pond is significantly warmer in the winter months than the stream above or below the pond, and substantially cooler in the summer. This moderation of extreme temperature variations benefits a variety of ecosystem inhabitants – particularly the native brook trout.