I will be comparing two ponds with different amount and variety of species in them. During this field trip the independent variable will be the different ponds (i.e. Peter's pond and Bay Pond) and the dependent variable

Bay Pond Field Trip Investigation

Planning:

Aim: To compare the diversity and amount of organisms in two different ponds (Peter’s Pond and Bay Pond).

Variables: I will be comparing two ponds with different amount and variety of species in them. During this field trip the independent variable will be the different ponds (i.e. Peter’s pond and Bay Pond) and the dependent variable will be the number of species and organisms in the two ponds. In addition, I will be looking at the pH, temperature, depth and the turbidity of the pond (the abiotic factors) to see whether these aspects have an effect on the presence of the organisms as I predict that there will be a relationship occurring. To make it a fair test, I will be performing the sweeps consistently, making sure that the technique that I use is constant so that it will be fair, I will also control the time, date and place (i.e. near reeds, in open water etc.) in which the procedure is taking place.

Prediction: I predict that the pond with the lower turbidity will contain a wider diversity and broader amount of organisms than the pond with the higher level of turbidity. This is because as one pond has a higher level of turbidity, the murkier and dirtier the water is and this increases when there is a lot of solids in the water and in this case it is due to a large number of carp in the pond. When there are a lot of particles, then there is less light reaching the plants that need the light for photosynthesis, which means that there will be fewer herbivores as they can’t make their own food. When there is a lot of turbidity, then fewer animals are able to live in the water; this is because the water will become warmer as the suspended particles absorb the heat from the sunlight. With less oxygen and light, there is less photosynthesis happening because there isn’t enough light for the plants to use hence there will be fewer organisms present because the carp disturb the sediments making the pond murkier. This means that the creatures living in the pond that are herbivores will not be able to survive and the carp will eat the predators of other species resulting in more of those creatures, therefore this will evidently affect the food chains and food webs in the pond. Also I predict that the pond with the higher pH will contain more herbivores because vegetation removes carbon dioxide from the water during photosynthesis and this leads to an increase in pH. Furthermore I think that the temperature of the water will have effects on water quality as the temperature will affect the amount of dissolved oxygen in the water and the rate of photosynthesis by aquatic plants etc. so perhaps the higher the temperature, fewer organisms will be in that pond.

Procedure: Firstly, I’m going to collect all necessary apparatus including, a net, for catching pond organisms in, making sure that the holes aren't too big so that even smaller organisms can be caught and recorded, a white tray so that it is easier to record my findings as the small animals will show up against it, a smaller plastic container and a white plastic spoon for picking up small animals from the tray and putting them in the smaller one and a magnifying glass, for looking at the small organisms. Next, one at a time (to ensure that no one pushes anyone over and fall into the pond) we will go onto the platform and gather some pond water (trying not to get any organisms already in it). Then I am going to sweep my net in the shape of the number “8” two times about 3 inches above the bottom of the pond (so that I don’t sweep as much pond weed and mud etc.) before quickly emptying my findings into the white tray. To protect myself whilst doing this I will cover any cut with waterproof plasters and will not get water in my mouth. Subsequently, I’m going to have a thorough look at my findings and record the amount of organisms in the form of a tally. If there are a lot of organisms collected then I will split the tray into quarters, and count the amount of organisms in one quarter and times it by 4 to give an approximate result. This obviously will not be as accurate as counting them one by one but it will save time and makes sure that we do not count anything twice. To identify each organism, I will use a classification key to find out what everything is. After I have identified and recorded what I have found, I will put the creatures back gently and efficiently and get some more water to put into the tray for the next person to perform their sweep.

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Each person is going to have one sweep each in their groups of 6 and we will record each sweep one after another. So at the end of each pond visit we should have 6 sweeps and an average worked out to see whether any of the sweeps followed a trend (if there is one) and to make sure that our results are reliable. To avoid random errors such as sweeping some organisms twice thus counting and recording them twice we are going to wait for 2 minutes before we do the next sweep and also I am going to keep the technique of dividing the white tray into quarters to a minimum. Furthermore, there will also be some systematic errors, so we will always double check with an expert about what an organism is as more than likely we will identify and mistake a species as something else and if we don’t record them correctly, this will affect us from getting precise results. To make things run smoothly and efficiently, as part of our group we will always have one person recording and writing results down, one to help empty the net onto the tray and one person to say aloud how may and what organisms there are to make it easier for the writer.

Also I’m going to measure the abiotic factors, using various instruments to do so: I will use a Secchi disk to measure the turbidity of the water, a metre rule stick to measure the depth of the area of the pond in which I will be sweeping and a pH and temperature probe to measure the pH and temperature. I will record these factors after each sweep to see if these factors have changed at all and if they have, I will see how this has affected the amount of organisms found and whether they are reliable by comparing these readings together.

Analysis:

Table of our results:

Table of Abiotic factors:

Conclusion: My results show that there are more carnivores, herbivores and detritivores in Peter’s Pond than in Bay Pond. This occurred probably because as Peter’s Pond is smaller the organisms are contained in a tighter space so we were able to gather more species whereas Bay Pond is bigger and that is why there weren’t as many organisms found in Bay Pond as in Peter’s Pond. Also I found that it was less turbid in Peter’s pond than it was in Bay Pond and theoretically they should be more herbivores in Peter’s Pond than in Bay pond and my results prove this. This refers back to my prediction and proves that it was correct as I also mentioned in my prediction that the pond with the higher pH will have more herbivores due to vegetation removing carbon dioxide from the water and this makes the pH rise because carbon dioxide is acidic and so removing it will make the pond more alkaline but my results show that this is not the case for these ponds as in Peter’s pond, it contains more herbivores but has a pH less than Bay Pond. Also I said that the higher the temperature, the less organisms that will be found because it slows down the rate of photosynthesis, and so less herbivores will be able to make their own food, and my results show this as Bay pond has less herbivores than in Peter’s Pond. There are less detritivores in Bay pond than in Peter’s pond but I do not think that this should have been the case as in theory; there should be more detritivores in Bay pond than in Peter’s pond because of all the carp in Bay pond which are detritivores as they feed off all the dead matter at the bottom of the pond. And I see no other reason why it should be the other way round (i.e. more detritivores in Peter’s pond than in Bay Pond) so therefore there must have been a systematic error during the procedure. Moreover I think that there are more carnivores in Peter’s pond than herbivores because all the herbivores are eaten by the carnivores as part of the food chain and food webs also a reason why there could be so many detritivores in Peter’s pond is that when carnivores eat the herbivores, the herbivores become dead matter, in which the detritivores will then go and eat. All my results are based around the fact that all living things within an ecosystem are interdependent. A change in the size of one population affects all other organisms within the ecosystem. Predator need to be adapted for efficient hunting if they are to catch enough food to survive. Prey species on the other hand must be well adapted to escape their predators if enough of them are to survive for the species to continue. This may well have had an effect on our findings.

Evaluation: From my results there was no trend as such but there was a few factors that I thought were inaccurate, for example, there were more detritivores in Peter’s pond than there was in Bay pond and this is inaccurate because there are carp in Bay pond whom are detritivores and so this should have boasted the population of detritivores this may well be down to the fact that we were only restricted to one little space of such a large pond. Also we found that there were more carnivores than herbivores in Peter’s pond which I do not think should have happened because we may have over looked some of the smaller creatures like water fleas as we found out later that there are more water fleas than we thought. Although a possible reason might have that they were hiding (on reeds etc.) from predators and so we did not sweep them up. In addition a cause for the lack of carnivores in Bay Pond could be due the area we were at, there wasn’t much sunlight and as most of the carnivores in Bay Pond are cold-blooded, they need the heat from the sun to help digest its food when it is eating hence possibly why there were fewer carnivores in the we were dipping at. Although I do not know if any of these were anomalies as such, we did not record our findings sweep by sweep, and therefore did not take any repeat readings to see if they were.

When carrying out the procedure, a number of problems cropped up during the experiment as well as reviewing it afterwards as well. I noticed that different groups dipped at different areas of the pond so it wasn’t just concentrated on one part of the pond, which makes the whole investigation slightly unfair as there could have been more organisms and their habitats in one region of the pond than another region. Furthermore groups dipped at different depths of the pond resulting in the same speculation that perhaps the deeper the pond, the more or fewer organisms there could be. So from this I can say that we didn’t take readings over a sufficient range as groups dipped in the same area, only focusing on the organisms that were there. In addition, different people used different sweeping techniques therefore within some groups their technique was not constant making it an unfair test consequently next time, to improve the experiment we should all use the same sweeping techniques to ensure that our results are fairer. Another major issue that I came across was the fact that people, between sweeps didn’t empty out their creatures and water hence resulting in a fault in the results as organisms could have been recorded twice or more. And also as we were not given specific instructions on how many sweeps we should conduct, some groups dipped more times than others and so their results would probably vary quite much from others, subsequently next time, we should all perform the same number or dips, again to ensure a fairer test. Also as a fault, we only measured the abiotic factors once, this is because there was only one set of the equipment and there wasn’t enough time for all the groups to take more than one set of readings. I did not record the results sweep by sweep but instead I added it all my findings into one row, as the recording sheet we were given told us to do this, so instead of having 6 sets of data (1 for each sweep) and an average worked out, it was just a general tally of how may organisms and what they were from what we swept for the whole duration.

The reliability of my evidence and data is not as accurate as I hoped it would be. This is because we didn’t do any repeats so I do not know whether my results are correct or not but as well as this, in terms of collecting the data, I think that some groups were more concentrated on the interesting, larger creatures that they failed to count all the smaller ones as well, this was especially noticeable from the results of Bay pond as groups discovered that they were hardly getting any organisms when in actual fact they were but they just didn’t count and record closely enough. Different people counted the creatures thoroughly whereas others skimmed through and performed the task very carelessly missing out on some of the creatures. As many people were not familiar with the organisms, there was a greater chance that we could have identified the wrong organisms making the data more unreliable. I think that next time if I was to perform this investigation again I would definitely follow my original plan, which was to record my findings sweep by sweep and compare it like that, because then I would have been able to look further into them to see if there were patterns and trends as well as assessing the reliability of the whole thing.

Overall, I do not think that my data is sufficient to support the conclusion because the procedure that was performed was not the same as I had originally planned, and it was also not consistent completely to make the investigation fair. I think that because of the measurements that we took were not reliable, I’m certain next time if I repeated the whole investigation again the way that I had planned it, and we would not get the same results that we have. Also I would definitely measure the abiotic factors at least twice to make sure that they are reliable as well. So based solely on my results and measurements, I would say that my conclusion is inaccurate and needs to be re-looked at a second time with a more suitable procedure.

Further work that I could do to provide additional evidence for my conclusion would be to change some of the abiotic factors, for example the pH of the pond. I would like to see whether my prediction is correct by testing out a variety of pHs to see what would be the minimum pH and the maximum pH in which organisms would be able to survive in. This could apply to the temperature of the pond. Also as we were only situated in one part of the pond to perform the investigation, I would like to expand this range to see whether different results come up in different areas depending on the environment around – whether this has an effect on the organisms in the ponds. I think looking at all these factors, will help me to be more confident in the validity of my conclusion and make it more secure. And perhaps I would be able to see clearly any trends and patterns and be able to analyse them better.