*Each net method must be used at least 5 times, preferably in different areas within the site, before switching to another method with the usage of the kick seine and the minnow net to have timed intervals of 2 minutes each before lifting and emptying upon the tray. With the dip net, it should be dipped between 5-7 times with some success in capturing organisms.
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Once all the groups have finished collecting, each group must then classify the captured macro invertebrates from their site. The Internet would be a great source for identification sheet; An example would be
- First gather all the jars and then create a 60-40 alcohol solution mixed with water and pour into the baby food jars filled with the organisms. This is the conversion from containment jars to kill jars
- Once the organisms are dead within the jars, use the tweezers remove the from the jar and place onto a slide and observe it under the microscope, take note of its appearance and use the Macroinvertabrate Identification site given in the above hyperlink to classify the organism
- With the 3 Petri dishes, label each one as either Low-Tolerance/ Sensitive, Somewhat Tolerant/Sensitive, and High Tolerant; Depending on the organism and what the macroinvertebrate identification sheet identified it as, place the organism in its respected Petri dish**
- Once labeled as one of the tolerances, for every sensitive organism collected, only counting each type once, paying no attention to quantity, make a note of how many sensitive macroinvertebrates were collected and multiply by 3; do the same for the somewhat sensitive/tolerant macroinvertebrates but multiple by 2; the same for the tolerant organisms but no multiplication is needed. What has been conducted is to find the index value per site.
- Once the index values for the tolerances have been concluded, add the three values to then gain the Total Index Value of the prescribed site which the collection had taken place. The water quality is then judged by the total index value: it is Poor (<11), Fair (11-16), Good (17-22) or Excellent (>22).
- Classify the water quality for each stream and share the data with the other groups.
- **If out of time to classify, cover the petri dishes with Parafilm to keep the organisms moist and prevent drying
- Once the Biological results have been collected and recorded, attain the Chemistry results from those who tested the chemistry of the river
Data Collection and Analysis:
Stream: Salt River
City: Mesa State: AZ
Collection Date: November 23, 2009
Weather conditions: Clear sky
Water Appearance: Clear
Stream-Flow rate: Normal
Site #1
Average depth at site: 2ft.
Average width at site: 60 ft.
Stream water temperature: 14.95°C
Water Quality Rating: 18 Good
Site #2:
Average depth at site: 3ft.
Average width at site: 80 ft.
Stream water temperature: 14.4°C
Water Quality Rating: 10 Poor
Site #3
Average depth at site: 3ft.
Average width at site: 80 ft.
Stream water temperature: 15.1°C
Water Quality Rating: 16 Fair
Site #4
Average depth at site: 3—6 ft.
Average width at site: 60ft.
Stream water temperature: 14.95°C
Water Quality Rating: 16 Fair
Chemistry Results:
Average:
Raw Data:
Conclusion and Evaluation
Conclusion
“If there is a high frequency of low-tolerance/sensitive organisms and the chemistry of the river support the frequencies then the Salt River is healthy, but if there proves to be a higher frequency of high-tolerant organism, and being supported by the chemistry results, it therefore states that the river is unhealthy.”
Concluding from the hypothesis and the resulting macroinvertabrate collection and classification, the hypothesis of the river would conclude its health to be fair. The conclusion is similar for the chemistry results. Throughout the experiment, the data from the data tables show that almost all the sites were reported to have sensitive/low tolerance macroorganisms. In order for a river to have a healthy system, the dissolved oxygen for a fresh water river should be 6ppm or greater to be considered healthy.
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From site one, the biology data shows 59 macroorganisms have a sensitive/low tolerance to the river with no tolerant macroorganisms. The chemistry data also supports that site one has a healthy system.
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From site two, the biology data shows 12 collected macroorganisms have a sensitive/low tolerance to the river with 3 collected tolerant macroorganisms. The chemistry data supports that site two has poor health due to its fluctuating pH.
- From site three, the biology data shows 8 collected macroorganisms have a sensitive/low tolerance to the river with 4 collected tolerant macroorganisms. The chemistry data supports that site three has a fair health.
- From site four, the biology data shows 23 collected macroorganisms have a sensitive/low tolerance to the river with 4 collected tolerant macroorganisms. The chemistry data supports that site three has a fair health.
The absence of ammonia does not affect the experiment as much as the absence of the nitrites and nitrates. In the testing of the water, the nitrates and nitrites were not present in the recordings, and would be needed to solidify the health claim of the river, but nonetheless, with what has been gathered, the river’s health is not excellent, nor is it polluted, but fair enough for the collected organisms.
Evaluating Procedure
Since the experiment was conducted in November, the temperature of the river rapidly changed from the early morning to noon, affecting the collection of the macroorganisms in the river. As the start of the winter season, the environment of the experiment sites were affected as the water tide levels of the river had fluctuated, changing the sites from the past few days. An assumption would be the release of the water from the local Roosevelt Dam that controlled the water levels. Excluded from the overall results, site five had failed to report any findings and thus the health of that site was not calculated into the overall conclusion.
Improving the investigation
The improvements that could be made for the overall experiment would to conduct not just once, but multiple times from the warm season of summer to the cold, and to have a longer allotted time to collect the macroinvertabrates within the river, as well as different hours of the day such as night and early morning. Also, with going multiple times during the year, with the water level changing occasionally but with the chance of having the experiment conducted with high water levels, collecting the different bugs over a long span of time can tell if the rivers health id dependant on seasonal changes within the environment, one such possibility being the lower health in summer due to the pollution caused by the human population that goes to the river recreationally. Besides that, more nets could be used so that there is no waiting in switching the equipment from site to site after each trial and any other helpful catching methods besides the most useful ways of capturing using the kick seine and the bucket.
