2022 Annual State of the Creek Report – Catlin Gabel Class of 2028
It’s always good to get back in the woods!
This was especially the case this year when 7th grade students from Catlin Gabel School arrived at Hyla Woods on an unseasonably warm and dry day. It was early October, time for our annual environmental assessment of Lousignont Creek. Over the course of six field trips this fall, students collected data at twelve field sites along the creek adding to our student-led ecological research study now stretching back to 2014. Important ecological concepts were investigated, field skills were honed, data were collected and analyzed. Then the writing began.
Each student drafted a “State of the Creek Report” blending the story of our work with their own evidence-based conclusions on the creek’s health. Through rounds of anonymous peer review, the class of 2028 has selected the following featured report to speak on behalf of their collective efforts.
I’m proud to announce that this year’s featured State of the Creek Report is authored by our very own citizen scientist, Diarra!
We hope you enjoy Diarra’s account below. We also hope you check out the links to follow to read this year’s runner-up report written by Tate as well as a folder of other student reports receiving “Honorable Mention.” Lastly, you’ll find an updated link to our database with all of our water quality data from 2014-2022.
Catlin Gabel Science Teacher
Without further ado…here’s Diarra’s State of the Creek Report (also in a snazzy Canva format HERE)
The Oxford dictionary defines forest as “a large area of land that is thickly covered with trees,” however throughout the Hyla Woods Field Research project I learned a much richer, more meaningful definition of it. A forest is an ecosystem, a community much like a human society. Where each being helps maintain a balance of give and take.
My name is Diarra and I am a seventh grader at Catlin Gabel Middle School. In the first and last week of October my science class was fortunate enough to get to take two trips to Hyla Woods to answer the question, “What makes an ecosystem healthy?” and to determine the water quality of Lousignont Creek before the Coast Coho salmon came to spawn for the season. This helps make sure we can support the salmon on their recovery and return to Northwestern creeks.
Going to Hyla Woods was grounding and inspiring. Since I’ve been a Catlin Gabel student for 8 years now, I was also able to go to Hyla Woods in second grade. This past involvement with the forest made my experience even more meaningful.
Throughout our two field research days, we conducted a series of tests to help us determine the overall quality of the water in Lousignont creek. We took both the air and water temperature. The optimal water temperature range for Coho salmon is 5-20 degrees Celsius. However the golden rule is the colder the better for salmon.
Testing the temperature also gives us information to make some inferences around what variables are causing the changes in temperature. These include the amount of riparian/streamside plants, as they block direct sunlight causing the water to be cooler and air temperature as when the air temperature rises so does the water temperature, thus why we also measured the variable of air temperature.
Our class average water temperature for the first round and second round of data collections was 10 degrees Celsius. The first round class average was 12 degrees Celsius and the second round class average was 8 degrees Celsius. This was somewhat expected as the first trip was earlier in the month when it was much warmer.
We also tested the turbidity which tests the amount of suspended sediment in the water. Turbidity can affect the temperature as water with more suspended sediment gathers heat. It’s important that the water isn’t too turbid as if the water is too turbid then it makes it difficult for organisms to sense their food and surroundings and it is likely that some of the sediments will get caught in their gills making it extremely difficult to breathe.
To test turbidity we use a Turbidity Tube, and drain the water out until we can clearly see the pattern at the bottom of the turbidity tube. Our class median for both rounds is < 5 NTU. This is the lowest that our test went and with turbidity like temperature the lower the better for Coho salmon. Turbidity is mainly raised by flooding, erosion and human/animals walking through the water.
The Dissolved Oxygen in water measures how much dissolved oxygen is in a body of water. To measure DO, Dissolved Oxygen, we measure it in parts per million or ppm. DO is important simply because it is an aquatic organisms way of getting oxygen and breathing. If a body of water has too little DO, it will be impossible for aquatic organisms to survive. Coho salmon need at least 8-12 ppm to survive. Our class average for both rounds of testing combined was 8.7 ppm.
pH measures if a sample of water has more hydrogen (H+) ions or hydroxyl (OH-) ions. If a sample of water has more hydrogen ions then it is considered acidic and if a sample of water has more hydroxyl ions its considered basic. The measurement system is that a score of 7 is neutral above 7 is basic and below 7 is acidic. Coho Salmon need water that is around the neutral of 6-8. If the pH is outside of this range it becomes hard for them to smell, which could prevent them from laying eggs as a female salmon only lays her eggs at the stream she was from and she has to smell her way back. Our class average for both rounds is 6.0.
On our first trip to Hyla Woods we put together a leaf pack and placed it in the stream. A leaf pack is a bag of leaves that is meant to attract and capture macroinvertebrates in the stream in order for us to identify their tolerance and sensitivity levels and make inferences about the overall health and livability of the creek. Three weeks later on our return trip we retrieved our leaf packs and sorted and counted the macroinvertebrates within. Using this data collected we were able to give the creek both a biotic index and EPT score.
The Biotic Index measures all of the macroinvertebrates collected and divides the total tolerance value by the number of macroinvertebrates collected to give an average taxon tolerance value. Each organism is given a taxon tolerance value. The higher the taxon tolerance value is, the more tolerant the macroinvertebrate is. This leads us to be able to make the inference that the less tolerant the macroinvertebrates in the water are the higher the quality of water, as it would need to be good quality water for a super sensitive macroinvertebrate to be able to survive in it. Our class mainly found mayflies, stoneflies, caddisflies and snails. A biotic index less than 3.7 indicates excellent water quality, 3.6 to 5.0 is good, 5.1 to 6.5 is fair, and 6.6 to 10.0 is poor. Our class average was 4.65.
An EPT score is the percentage of the macroinvertebrates that are mayflies, stoneflies and caddisflies. We use these three macroinvertebrates because they are among the most sensitive. Thus the higher your EPT score the better as it means there are more sensitive macroinvertebrates in the creek. Leading to the conclusion that the creek is in good health the more macroinvertebrates that are sensitive can survive in it. If the EPT score is above 35% it’s considered good and if it’s above 50% it’s considered excellent. Our class average was 49.1.
Overall it’s safe to say the Lousignont Creek is in good condition for the Coast Coho Salmon and is helping to support a healthy ecosystem at Hyla Woods. I can make this conclusion with certainty because all of the tests we ran, temperature, pH, DO and turbidity were in their optimal range. The EPT and biotic index scores were also close to excellent and in the optimal range.
The conclusion is quite similar to that of previous years. In comparing past years data it is clear that all of the tests have stayed within the optimal range with the biggest fluctuations being on the EPT score. The EPT score has steadily dropped for the past two years. However, it is still in a good range. There has also been a spike in the snail population. This leads to snails making up a greater percentage of macroinvertebrates, which reduces the EPT score. It is also worth noting that the DO and pH both decreased meanwhile the temperature increased. This year the precipitation was also very low, making the creek shallower. The reduced water flow/depth, likely resulted in the water heating up more than would be expected under typical conditions.
The cool thing about Hyla Woods is that they are finding new ways to look at the forestry and lumber industry while still managing an experimental forest in a nature focused way. The way Hyla Woods is run helps remind me that not only must we question the system but we must find new perspectives and ways to rebuild the system with our priorities straight.
On our first field research day, we also got the chance to do some photography work within the forest. To me this really highlighted that we take our forests for granted and if we continue to have and support such an extractive economy when it comes to the forest and lumber industry we won’t have these forests for future generations to enjoy.
Want to read and learn more? We hope so. check out the links below: