Discussion
Biotic
Data:
In terms of biotic data, there
was hardly a change between the percent cover of algae during the first
randomized testing in September and the second sampling in November.
Though I had expected a slight change (due to temperature
difference), this data was not surprising to me.
Manipulation Data:
I had expected a change in both the
temperature and the dissolved oxygen composition after placing the
trashbag over the tidepools. In the first trial, the
oxygen consistently declined in all three tidepools after the hour
under the trashbag. This is consistant with my hypothesis. As there was
no light reaching the photosynthetic algae in the pools, the algae was
not able to photosynthesize, meaning the oxygen content would be
declining without being able to replenish itself. The temperature data
also slightly increased, although not enough to be significant (p value
= .12)
Neither salinity nor pH changed significantly. In trial two, the oxygen
content did not change significantly. I believe this is due to the fact
that the weather was overcast and there was no sunlight to begin with,
meaning the trashbag would not have a large difference on the
photosynthetic capability of the algae.
Future Experiments:
I believe this experiment was not as
effective as I would have liked it to be because we had a limited time
to conduct the manipulation each time we were in the field. Because of
this, we were only allowed to leave the trashbag on the pool for one
hour, which I do not believe to be sufficient time for a huge effect to
take place. I would like to go back into the field and try the
manipulation experiment with a longer time frame. I would also like to
be able to manipulate other factors, such as the snail content, and see
what the removal or addition of snails does to the water composition of
each pool. I believe there are many more experiments that can be done
with the water composition and I am anxious to see what comes of more
testing in the field.