State of the Creek Report 2019 – From Catlin Gabel School 7th Graders
2019 State of the Creek Report
Catlin Gabel Class of 2025
Summer ends, school begins, maple and alder leaves drop to the forest floor…and the seventh-grade science students from Catlin Gabel School head to Hyla Woods for their annual assessment of Lousignont Creek. For seven years and counting, these student-scientists have flexed their newfound field ecology skills to test the health of the creek in advance of the returning Coastal Coho Salmon. The Coho were likely in the deep waters of the Pacific when the students first came to the forest. The salmon are now returning to Lousignont Creek, and our seventh-grade field scientists are proud to share their 2019 State of the Creek Report just in time. Each student has written their own report, then, as a class, they reviewed and selected a single report that shares the story of their work and presents the conclusions drawn from their collective data.
This year, I’m proud to share that our featured State of the Creek Report is authored by our seventh grade scientist, Chip! Congratulations Chip!
In addition to Chip’s report, we invite you to read the additional “honorable mention” reports by Erin and Julia, as well as a collection of finalist reports from each science section (linked following Chip’s report). If you’d like to take a deeper dive into the data, you’ll find a link to our database (including all water quality data from 2014-19). You’ll also find the results from a pilot graphing project carried out by this year’s seventh grade math classes, which analyzes the data for patterns in water temperature, pH, and dissolved oxygen over the past seven years. Huge thanks to all the seventh grade math students and to their math teachers—Alix, Pongi, and Ema—for taking this project on!
7th Grade Science Teacher, Catlin Gabel School
My Hyla Woods Experience
On October 8th and 30th, my science class traveled by bus to Hyla Woods, a “6th generation experimental forest business in the Oregon coast range working towards a better model of forestry.” We were investigating whether or not Lousignont Creek, a stream that runs through the heart of Hyla Woods, was healthy for the Coho Salmon that return every fall to spawn. This is an important question because it can determine whether the salmon can transport their millions of nutrients, which is the foundation of river ecosystems and remain constant as the center of economies and cultures.
After traveling to Hyla Woods for the first time, our group hiked to a clearing outside of a lodge where we introduced ourselves, took a few minutes to collect ourselves, reflected on what we were about to be doing, and got in a good mindset for our field research. After that, my class ambled to a cabin in which we were promptly asked to go back outside and ready ourselves for the six room poem that we were about to write. Both trips to Hyla Woods, we took a moment to admire the forest before quietly trekking to Lousignont Creek reflecting on the importance of the visit.
Our Group’s Leaf Pack
During both visits to the creek we went to our group’s field site, site G, which is one of twelve sites along the half-mile stretch of creek tested by our class at Hyla Woods. On those cold and cloudy days, we tested the air temperature, water temperature, pH, dissolved oxygen (DO) and turbidity of the water. On our first trip, we also tied a leaf pack onto the root of a tree. A leaf pack is a bundle of leaves, which creates an excellent habitat for aquatic organisms (also known as macroinvertebrates). We were using the leaf pack to capture these macroinvertebrates, which can be used as bioindicators to determine if a stream ecosystem is healthy. Some macroinvertebrates are more sensitive than others; if these are present, we can infer the creek must be healthy, not just for macroinvertebrates, but for the salmon too.
The first test that we completed was water temperature, which is an important test to take because all organisms have a unique range of water temperature in which they can survive, so if the water heats up, it can disrupt the whole food web. We tested the water temperature by putting a thermometer into the water or air for two minutes before looking at the temperature. Our group got temperatures of 10 and 4 degrees Celsius on the two days respectively, which is inside the healthy range for water temperature of 5-15 degrees Celsius for salmon as well as most aquatic life. Overall, our class average from the twelve research sites was 7.5 degrees Celsius which, compared to years past is a little colder, and still very healthy for salmon.
My research team doing our work
The second test our group did was pH which is a measurement that concludes how acidic or basic water is, which is important because organisms are adapted to specific pH ranges. If the water is too acidic or basic the organisms will cease to function. Our group recorded a pH of 6.5, which is just inside the 6-8 range considered suitable for salmon. Our class’s average was 6.5 for pH, which compared to previous years is nearly the exact same, meaning that the creek has had a healthy pH for a number of years.
The third set of data our group gathered was that of dissolved oxygen (DO). It’s necessary to have a healthy amount of dissolved oxygen because it’s essential to break down food, and complete other bodily functions. DO is unlike the other tests because most of the experiment is done in class. To find the DO, our group added, reacted, and stirred various chemicals until we ended up with 8.8 and 12 parts per million (ppm) of oxygen, respectively for our two research days. This was inside the optimal minimum of 8-12 ppm, proving that the stream was healthy! At the end of the tests, our class’s averages was 11.2 ppm, which were slightly higher than previous years.
Our dissolved oxygen sample, ready to bring back to the lab
The final test our group did was testing the turbidity of the water, which shows how cloudy the water is and is a consequential variable because, if the water is too turbid, it can indicate an unhealthy amount of pollution and can increase the heat of the water, dropping the DO levels and hindering the aquatic organisms ability to breathe. To find the turbidity of the creek, our group filled up a tube with stream water and released the water until we could see the checkered bottom of the tube. After testing how many centimeters of water we could see through, we converted the number of centimeters into NTUs (Nephelometric Turbidity Units). The most common turbidity measurement across the research sites (the mode) was <5, which was within the optimal range (below 25-70 NTUs). Overall, the class generally had the same results as well as the classes proceeding us.
After collecting and sorting the leaf pack, my group found 4 mayflies, 15 stoneflies (including 1 giant stonefly which is a very good indicator as to the good health of the stream in the past), 1 midge, 1 black fly, and 7 snails. This added up to fewer macroinvertebrates than most groups found, but is similar when compared to previous years’ data.
A giant black stonefly larva (Pteronarcys dorsata), the largest macroinvertebrate collected in seven years of research…by far!
After collecting and identifying our macroinvertebrates we completed two tests to fully understand what the macroinvertebrates could reveal to us about the creeks health. These tests were Biotic Index and EPT score.
To calculate the Biotic Index of our group’s leaf pack we multiplied the number of each species we got by their taxon tolerance value, a measurement of how tolerant to pollutants the macroinvertebrates are, and added them all up, divided them by the total number (28), to get a biotic index of 3.2, which suggests “excellent” water quality. This score contributed to the class’s average score for biotic index of 3.9, which indicates “good” water quality.
To determine the EPT score, my group calculated the percentage of mayflies (Order Ephemeroptera), stoneflies (Order Plecoptera), and caddisflies (Order Trichoptera) in our leaf pack because they are very environmentally sensitive and can’t live in harsh conditions. We added the three previously mentioned macroinvertebrate Orders together and divided that by the total number (28). We finished with an EPT score of 67.9 which is well over the optimal score of <27 (suggesting “excellent water quality”) and very close to the class’s average of 68.5.
Overall, each test, including the Biotic Index and EPT score, indicates the creek is in excellent condition because all of the variables are inside their optimal range, and have been for many years. Reflecting on the experience, I loved going to Hyla Woods, and hope only the best for the stream and future groups
Want to read more from Catlin Gabel Students about their experiences and conclusions from their Hyla Woods field research this year? Check out our two honorable mention reports by Julia and Erin, as well as a collection of reports nominated by each science section:
Julia’s State of the Creek Report: click here
Erin’s State of the Creek Report: click here
Science Class report finalist folder: click here
If you’d like to take a deeper dive into the water quality data over the past seven years at Hyla Woods, check out our master database and the graphing project this year’s math classes took on, in search of patters within the data.
Hyla Woods Master Database (2014-19):click here
2014-19 water quality analysis (Water Temp., pH, DO): click here
(Editorial Note From the Hyla Woods Team – We are super impressed by and grateful for the excellent work that the Catlin Gabel students do in the forest. The results are interesting and helpful to us as we continue to try to be good stewards. These young scientists and their crazy teachers are valuable parts of the team!!)