October, means fall weather has officially arrived in Austin, Texas. The days begins to chill down, and our lows scratch the surface of 60s during the nights and mornings, and highs of 80s and 70s when it’s bright and sunny. For this entry I observed an extension of Walnut Creek which leads through the backyards of many people in my neighborhood. I wanted to compare general differences in wildlife when nature is closer to human development which potentially, could have greater impacts on the environment than human activity at Walnut Creek Park where nature is more shielded from the effects of urban life.
The first difference I noticed was that, while the Walnut Creek in the park had algae, it generally looked like the picture on the left, you could still see around the water and the color was bright green. When Walnut Creek reaches my neighborhood which is about 6 minutes away, dark concentrated areas of algae appeared sporadically. The dark spots occurred where water was still as opposed to lighter areas of concentration where the algae was constantly being pushed by the flow of water. If runoff water does get into Walnut Creek it would more likely happen in my neighborhood because Walnut Creek is at the bottom of houses built on top of inclines, and if chemicals are used to treat the yards of these homes, the nutrients from trying to achieve green perfect lawns flows down the hills and into the Creek.
When there is algae levels shown on the left picture, life is able to thrive, you can see fishes swimming above the algae, speckled flies skating the waters, and other forms of aquatic plants besides algae. The amount of nutrients in these areas are likely to be more regulated because water is flowing so they can’t just pool in one area. There were no signs of life surrounding areas where algae was so concentrated the color became black and light could no longer penetrate the surface.
While you would think an increase in algae leads to more life because a byproduct of plants producing glucose is oxygen, like in the picture above where you can see the oxygen bubbles on the surface of algae. The reality is that algae blooms upset ecosystems because they use all the nutrients before other organisms get a chance to, and because algae grows so rapidly and has a short life span. This leads to excessive amounts of organic matter which is trying to decay. The decaying process consumes oxygen in the water and leads to a further decline in the diversity of freshwater ecosystems, because plants and organisms could otherwise thrive in those areas if not for the lack of nutrients and insufficient dissolved oxygen.
“A thing is right when it tends to preserve the integrity, stability and beauty of the biotic community. It is wrong when it tends otherwise.” Aldo Leopold, A Sand County Almanac.
While this is a small representation, Algae blooms are in fact a huge threat to freshwater ecosystems and because we depend on freshwater, they’re a huge threat to us as well. Food production is important and while it should be priority, more sustainable solutions need to be found, the cost of fertilizers on ecosystems is one humans simply cannot afford.
