Microorganism populations

Micro-organism populations in the samples were studied under a microscope at x400 magnification. I compared populations of micro-organisms by eye (as it was often difficult to distinguish a group of organisms from a single organism, making an exact count difficult to determine, and the motility of the organisms made the use of the hemocytometer difficult).

Overall, I observed that population size and motility of organisms tended to increase as one progressed further into Pedder Bay (the smallest populations were observed near the prison; the largest were observed near the Marina). Furthermore, populations near the surface tended to be larger and more motile than those at a depth of 3m. The depth discrepancy may be explained by the fact that phototrophic micro-organisms find more light at the surface than at 3m depth. The locational discrepancy can be accounted for by the difference in temperature between area beyond the mouth of the bay and the Marina (average temperature being higher as one approaches the Marina). This may be due to surface runoff providing nutrients for the bay micro-organisms, or runoff of organisms themselves into the bay. Alternatively (or in addition), the higher temperature in the bay may be better at supporting life; however, higher temperatures may also imply lower dissolved oxygen content, which would theoretically hinder aerobic micro-organisms.

All in all, I see that the inner bay area (close to the Marina) seems to be more hospitable for micro-organisms and that micro-organism populations tend to flourish more in the shallower and more sheltered bay area than out beyond the mouth of the bay.