Hello Creek Watchers!!
Another early fall marks the annual time for habitat assessments.
The evaluation of habitat is a vital component for fully understanding factors that influence the health and biological integrity of an aquatic community. The interaction between watershed features and land use characteristics plays a large role in determining the quality of an aquatic habitat. The condition of the habitat is evaluated using ten different physical parameters. Each of these parameters is numerically scored after visual observation of the stream reach, which is typically 100-150 feet, or full line of sight for most stream segments. The numerical scores for all parameters are then summed and the value obtained places the stream within one of the following categories:
|Optimal||16 – 20||160 – 200|
|Sub-Optimal||11 – 15||110 – 150|
|Marginal||6 – 10||60 – 109|
|Poor||0 – 5||0 – 50|
The Wissahickon is officially “impaired” and has been listed on the EPA’s 303(d) list for many years, so it is not surprising that many of our habitat assessments show the Wissahickon to be strongly in the “sub-optimal” category, and some in the “marginal” category.
To learn more about assessing a stream site and to participate in habitat assessments next year, don’t forget to attend one of our training sessions at the end of the summer in 2018!!
This year 8 Creek Watch sites performed their assessments (compared to 5 assessments in 2017). As assessments are tallied over the years, we can start to see changes in scores and identify patterns. *NOTE: These can also change as a result of a different volunteer performing the assessment – everyone has a different lens!
2 sites were evaluated for the first time this year. 4 of the 8 sites evaluated increased in score this year. 2 decreased in score. We need at least a few years of data before we jump to conclusions about trends and patterns.