Method:
) for obtaining organisms you have to fill the trays with roughly half pond water, preferably away from the area you are studying to make it a far test so you are not taking out any organisms out of your area. Then you use a net to sweep through the top layer of water of your area making sure the whole area have been swept. Do this round 3 times to make sure you have obtained enough organisms. Then place your findings on the first tray. Do this a further 2 times for the middle and bottom layer, making sure they are put into different trays for examination. After you have obtained your organisms and weed etc. you are ready to inspect your findings. This will involve taking out the organisms (each stage separately) and placing them in small see through dishes, placing same species together. This should be done for each stage until all organisms have been obtained. Next you must identify them, using the Organism identifier and microscope to establish what each organism is. You must then identify which organism is in which trophic level. After this you have to count and weigh the organisms. As there where only a few of each organism we decided to weigh all of them instead of weighing one as a representation, this making the investigation for drawing a pyramid of biomass fairer overall. After obtaining all of this it will then be possible to draw pyramids of numbers and pyramids of biomass to show your results.
Results
The results shown below are listed as they where obtained from each of the three layers (* not trophic level):
Top Layer of pond:
Boatman (x 1) = 0.77g
Stone fly lymph (x 3 )= 0.75g
Hertly larva (x 1) = 0.12g
Water mite = 0.10g
Weed = 0.6g
Middle layer of pond:
Leach (x2) = 0.43g
Weed = 63g
Mosquito papa = 0.2g
Bottom layer of pond:
Great water boatman (silver red eyes) (x 4) =0.5g
Weed = 26.7g
Swimming Mayley Nymph (x 8) = 0.5g
Stone fly Nymph (x 4) = 0.58g
Bloodworms (x 7) = 0.79g
Skreach beetle larvae (x 4)= 5.2g
Beatle larva (x 4) = 1.31g
Evaluation
Overall I felt the investigation went well, but by no means accurate to take firm readings from. This is because of a number of reasons, these being that the method of obtaining creatures was somewhat prone to being inaccurate as it would have been almost impossible to obtain all the organisms within the area specified. Another source of inaccuracy was that the area to which we where looking at (1m2) was only an estimated field as we did not have any guidelines as to where the boundary stared/ended causing inaccuracy in the results. Also as we only took a sample on one small section of the pond it would be unrealistic to say that it was a representation for the whole pond. Also when we took the organisms out of the trays some may have been left uncounted for or alternatively too small to count.
But from the results we did obtain it was possible to draw pyramids of numbers and biomass however inaccurate the results may have been. To further this investigation I would look at making the whole investigation a little more accurate than it actually was. I would do this by using different types of obtaining the organisms such as kick sampling. I would also look at what organisms live at varying oxygen levels or pollution levels.
