CRC completes aquatic plant survey

In July and early August, CRC surveyed key lakes in the Clearwater Valley to document absence/presence of aquatic invasive macrophytes (plants). Heidi Sedivy, a CRC employee with expertise in Aquatic Invasive Species (AIS), conducted the survey with the help of both CRC staff and volunteers.

CRC is happy to report that based on our findings, no new invasive plants were detected in any of the lakes surveyed – Seeley, Placid, Salmon, Big Sky, Alva or Inez. While this is good news, it should be noted that the invasive fragrant water lily continues to spread unabated in all lakes other than Big Sky Lake and Lake Inez. Also, the accelerated growth of native vegetation, such as the horsetail population in Salmon Lake, is a potential area of concern and may be due to a combination of nutrient loading and warmer water temperatures. Additional analysis would be needed to better understand the drivers of accelerated growth rates for specific native macrophyte species.

CRC has provided a report documenting its findings, summarizing the breakdown of species and abundance of plants found in each lake. The report can be found on the CRC website (crcmt.org). While the survey and associated report provides useful information, it should be remembered that surveys are representative in nature, and do not definitively guarantee the complete absence of invasive plants in the lakes surveyed. Therefore, it remains important to CLEAN, DRAIN and DRY your boat to the greatest extent possible even when transferring your watercraft from one lake to another within the Clearwater chain. And to remove ANY and all vegetation from your boat before launching into another waterbody!

The Montana Department of Natural Resources provided the funding for this survey, in cooperation with the Montana Department of Fish, Wildlife & Parks.