Human activities impact the water quality of streams. Some of these activities include the addition of salts via road salt application before winter storms, irrigation runoff, agriculture runoff, and leaky sewage pipes. The addition of salts into streams is considered salinization; therefore, the increased salinization of streams may change the chemistry and composition of stream water, impacting the organisms occupying them.
The increased salinization of streams negatively affects the tiny organisms that occupy them. Scientists can analyze how these organisms are impacted by measuring the biochemical oxygen demand. Many freshwater organisms perform a process known as respiration to gain energy so they can grow and stay alive. This process uses oxygen and organic matter (i.e., leaves and branches) to produce this energy. The tiny organisms that live in these streams are not visible to the naked eye; therefore, they consume oxygen and organic matter that has dissolved in the stream water. Biochemical oxygen demand (BOD) measures the amount of dissolved oxygen organisms consume. Hence, BOD gives insight into the productivity of these organisms within a stream.
Washington D.C. and Maryland's four streams of concern are Hickey Run, Paint Branch, Rock Creek, and Scotts Level Branch. These urban streams are monitored by the United States Geological Survey and the University of Maryland and are known to have high salt inputs from human activities. Stream water and sediment will be collected from each study site to implement a 5-day BOD experiment. The experiment will consist of multiple treatments (i.e., low salinity, moderate salinity, and high salinity) to investigate how salinity may impact the productivity of the tiny organisms within the stream water. The dissolved oxygen will be measured before the onset of the experiment and again at the end of the experiment. The difference between these two measurements will reveal the biochemical oxygen demand. A low value indicates that less oxygen is being removed from the stream water, while a high value indicates more oxygen is being removed. The data from these experiments will be plotted to reveal any trends or potential salt thresholds for these organisms. Additionally, literature reviews will help identify the potential reasons for these effects on these organisms.
Hi Ashley, I think you have a rally interesting post. I enjoyed the title, I think it is very clever and would certainly get the attention of a general audience. I liked the picture you have, although a figure caption that includes information about the location of the picture might be helpful. I also thought your third paragraph was an abrupt switch, so I might add a sentence to transition from the second and third paragraphs. I am excited to see the results of your BOD experiments!
ReplyDeleteHi Ashley, this is a great blog post! I found the title very catchy and attention-grabbing. You did a great job at introducing the concept of salinization which allows the general audience to understand the rest of the post. I agree with Andrew in that the transition to the third paragraph is rather abrupt. I think a transition sentence or two and maybe an additional figure that shows where these streams are would be helpful. Great post!
ReplyDeleteHey Ashley! The way you write is very straightforward, to the point, and easy to understand which is great! As for ways to improve, I feel like this blog could be made more accessible if you related more to the audience. What are everyday things people do that contribute to salinity levels (road salt), why is the productivity of the organisms in the lake important to the average joe? Otherwise, great job--can't wait to hear more about your experiments!
ReplyDeleteHey Ashley, great to hear about your experiment. You outlined the basic processes and what you want to measure very clearly and succinctly, and I think your use of terminology was perfect, as you defined several terms when necessary. My understanding is that the purpose of your experiment is to uncover the degree to which salinization of streams negatively affects these microorganisms, and also how different organisms may respond to salt. Obviously overall they react negatively, but perhaps there is an intricate response system. To take home the message of your experiment purpose, it may help to add what is still unknown- perhaps it is still unclear the exact mechanisms that occur when salt and microbial organisms interact in this environment, and then touch on how your experiment can uncover these ambiguities.
ReplyDeleteGreat job!
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