My class did a field study in the Coquitlam River and the Oxbow Pond. The objective of this field study was to determine the quality of the water in both study sites. There are 8 water quality factors important in all waterways. We measured the value of each of them in the river. They are:
- Temperature (temperature change) 4.5=Q value 78 (weighted Q value =10.92)
- pH level 6 = Q value 7.95 (weighted Q value =7.95)
- Dissolved Oxygen 92 = Q value 95 (weighted Q value = 21.85)
- Turbidity 2 = Q value 92 (weighted Q value =10.12)
- Nitrates 10 ppm = Q value 50 (weighted Q value = 7)
- Phosphates 0.4 = Q value 74 (weighted Q value =10.36)
- Total Dissolved Solids 50 = Q value 87 (weighted Q value =8.7)
- Alkalinity (we did not measure alkalinity)
For the Coquitlam River, my class discovered that between these 8 factors, the water quality level ranges from 71-90. We found this number by adding up all the weighted Q values of each factor. The water quality index tells us that that level of water quality is considered “good.” When we were collecting invertebrates at the river, we found these specimens:
| 4 stoneflies |
| 4 mayflies |
| 1 caddisfly larva |
| 2 stonefly nymphs |
| 1 riffle beetle |
| 1 dragonfly nymph |
There were also some crows. The invertebrate community also represents the health of the river. This group of critters tells us that the river water quality must be good because some bugs such as stoneflies can only live in good quality water. I think that the Coquitlam River is a healthy watershed ecosystem full of life and good quality water.
As for the Oxbow Pond, the critters we collected were much more interesting and diverse than the ones at the river. They are as follows:
| 4 gilled snails |
| 1 Scud |
| 1Water mite |
| 9 water boatmen |
| 1 caddisfly |
| 2 damselfly larvae |
| 2 stick bugs |
| 2 mayflies |
| 1 dragonfly larva |
| 1 rifle beetle |
| 1 water snipe larva |
| 3 snails |
| 1 dragonfly |
| 1 ladybug |
We also found 7 fish, 3 tadpoles, and a chipmunk. From these critters, we can estimate that the water quality is rather fair, almost good. We can confirm this by checking the water quality results.
- Temperature (temperature change) 1C=Q value 90 (weighted Q value =12.6)
- pH level 6.5 = Q value 71 (weighted Q value = 10.65)
- Dissolved Oxygen 90 = Q value 94 (weighted Q value = 21.62)
- Turbidity 8 = Q value 80 (weighted Q value =8.8)
- Nitrates 10ppm = Q value 50 (weighted Q value =7)
- Phosphates 5 = Q value 13 (weighted Q value =1.82)
- Total Dissolved Solids 100 = Q value 85 (weighted Q value = 8.5)
Here we see that we are correct because the final approximate water quality index is 70.99 which confirms our estimate.
I think that the Oxbow pond is an interesting and rather healthy ecosystem with a diverse invertebrate community.
Comparing the 2 sites
Comparing the water quality from both sites, we can tell that the Coquitlam River has better water quality than the Oxbow Pond. There is a much more diverse community of invertebrates living in the pond than in the river. Although the water qualities are different, they are close together on the water quality index. I can tell that the 2 water samples have similar quality because there were many of the same critters in both study sites.
I think that the more invertebrates in a waterway, the worse the quality of that water is. I think this because if I think logically, the more invertebrates live in a waterway, the more nutrients they take from that water. If there are many critters in the water, the more invertebrate excrements will be in that waterway. So, in conclusion, the fewer invertebrates in water, the better quality of that water.
My Response
I think that this assignment was a very educational and enjoyable experience. I particularly enjoyed going to the pond and discovering new invertebrates. I learned a lot of new things. The most important piece of information I will take away from this project is the 8 water quality factors and how to measure them. I also enjoyed learning about identifying invertebrates and using that information to take an educated guess on a waterway’s water quality. I think that recording alkalinity as part of the 8 water quality factors would make this activity more meaningful.