Jeremy Williamson is the Water Quality Specialist for the Polk County Land and Water Resources Department. He is also also a member of the Emerging Threats and Opportunities subgroup of the St. Croix River Basin Team and is part of a national group that assesses freshwater harmful algae blooms that includes the CDC and the USGS. His work includes studying the chemistry, biological aspects, and the physical features of different water bodies and their surrounding watersheds.
He works with a variety of different water bodies throughout the county and partners with different lake and river groups, state and federal agencies. “This summer I believe we are working on eight or nine different lakes and some tributaries and we often do monitoring on the St. Croix River with the National Parks Service and St. Croix River Association. We will do several additional water bodies specifically for aquatic invasive species and I am on the committee for two additional comprehensive lake management plans. We are usually busy, Polk County boasts 437 lakes (over 200 named) and 365 miles of river,” said Williamson.
He feels generally, the lakes around Amery are in good shape. “North and South Twin and Pike Lakes are all very clear and healthy for the most part. Wapogasset faces some challenges with algae blooms, but has an active group working on that and the Apple River Flowage has some plant and navigation issues, but also have a very active group and are also installing many Healthy Lake projects such as shoreline restorations. There are many other small lakes around the area we just do not have enough data on,” he said.
Winter limnology, the study of inland waters, is really an emerging area of research. “Qualitatively I can say that when we have long winters with long periods of ice cover and snow the plant growth in lakes seems quite reduced and the lakes tend to remain clear for a longer period of time,” said Williamson. He explained new research suggests more monitoring in the winter is the catalyst for how a body of water will respond in the spring and summer.
Williamson said, “Many lakes in the area have curly-leaf pondweed and that can prove to be problematic especially for navigation. A few area lakes have Eurasian watermilfoil which is problematic, but citizens groups really are doing a good job of managing it, including the Amery Lakes District as it is found in Pike Lake and recently discovered in North Twin. Deer Lake also has zebra mussels present that people should be aware of.”
The most important thing boaters can do to reduce the risk of introduction of invasive species is to keep boats, trails and equipment clean and dry. Also, it is important to be aware of what invasive species may be present in a water body that you are visiting. The recommendation is to let you boat and equipment dry for 5 days in order to reduce the risk of spread.
“Also, with the explosion in the wake boat industry, folks should be aware of the shape and size of lakes. Most Polk County lakes are under 11 meters deep. This means they are sensitive to water column disturbance. Disturbing the water column down to the sediment water interface can lead to nutrient release from the bottom (usually phosphorus) and proliferate algae blooms. Also recreating too close to shore can cause erosion and add sediment and nutrient to the water as well. In addition being to close to shore can be a safety hazard,” Williamson said.
He feels anglers should also make sure their live wells are dry and clean. Williamson said, “The motto is ‘Clean, Drain, Dry.’ This is especially important to stop the spread of Viral Hemorogenic Septicemia (VHS), which is a fish disease. In addition, bait should not be transferred from lake to lake, especially if the water has been replaced in a lake where one was fishing as that could spread disease.”
He said most local lakes are fine for swimming. Precautions should be taken if there are algae blooms as they can be toxic (blue-green algae can produce a variety of toxins). However, for the most part area water bodies are fine for full body contact.
Williamson said, “A general rule of thumb if you see a suspicious plant is to bag it in a zip lack bag with just a little bit of water label it with a small piece of paper and pencil and bring it to the Polk County Land and Water Resources Department to be identified, verified, and sent to the state to be vouchered.”