Environmental sciences Lab-2(Stream Pollution)

Method:

• First each site was marked in order to start the experiment.
• Stream was divided into 5 sites in order to analyse the stream pollution index of the stream carefully & accurately.
• For each site(1-5), Insects were searched & caught by a Net.
• Insects were then placed in a bowl of water in order to identify the species.
• Turbidity of the stream was discovered.
• pH level of the stream was discovered
• Temperature of the stream was discovered
• Dissolved oxygen for each site was measured using a dissolved oxygen meter
• Insects were inputted in a table according to their Sensitivity rating, weight factor, Tolerance level & Number of Insects.
• Stream pollution Index of the stream was then calculated.

Data collection & processing:

• Ph of water on each site :7.6
• Temperature: 17.1
• Turbidity: 0

• Site 1:1 Larva
• Site 2:1 water strider
• Site 3:1 water strider

              1 fish tadpole

• Site 4:1 Larva

              1 water strider

              1 Needle bug

• Site 5: 2 dragonfly nymph

Stream Pollution Index: Total of column D

                                          Total of column C                                                                                    

                                          =17/5

                                           =3.4,which is fair.   

Stream Pollution index for each site:

         

  Dissolved oxygen level(mg/l)

Average Dissolved oxygen: 2.96

   

Conclusion:

Based on the data above, We can observe that the stream pollution index gives a value of 3.4 which is fair,however in some sites while quality of water was just reaching a good level while in some sites quality of water was poor. Average dissolved oxygen for the stream was 2.96 which is harmful to aquatic life.

Evaluation:

From our research & findings on this experiment we have discovered that the Stream Quality rating was fair, However dissolved oxygen is not suitable to aquatic life, obviously where dissolved oxygen is less than 3 it is harmful to aquatic life and were only seeing bugs that live on top of the water like the water strider on sites were dissolved oxygen was less than 3 and not finding other fishes at various sites. However this experiment could have been performed more accurately if :

• By widening our time scale, for instance if we could have performed the tests at 3 different points in the day. To see whether if different dissolved oxygen levels would have been obtained & to see if there were any movement in the aquatic life.
• By increasing the size of the nets, more aquatic life could have been captured & it could have helped us determine the stream pollution index more accurately.
• It would be interesting to come back & run the test again to see if the levels are getting worse, and determine rate of change in the Stream pollution index & Dissolved oxygen.