Biodiversity trends across urban and rural lakes in Ohio

1) What do you like most about this manuscript? 

• I really enjoyed reading your manuscript, you did an excellent job! One thing I appreciated was how you explained scientific terms in a way that is easy to understand for readers who do not have a background in ecology! This is an important skill for scientists to have as we often have to communicate our findings to people from different backgrounds. Also, the way you presented your data was really effective and meaningful. For example, I really appreciated how you kept a consistent color scheme throughout all of your figures. This made it very easy for me to interpret your data and analyses. Further, you explained the importance of your work very well, by highlighting the few studies related to this current topic and why biodiversity is important for an ecosystem. 

• Your passion for your study shined through your manuscript. Overall, I was impressed with this preprint, and I hope you take time to celebrate  the extensive effort you put in! 
  

2) How effectively did the background information support the research question? What additional information would be helpful for the reader?

• The background information provided did a great job of communicating the importance of the research being done: biodiversity is an indicator of lake health and while the lakes of Ohio provide drinking water for many people, there are few studies done to understand how biodiversity of a lake can differ based on how close it is to a city and how these changes may affect lake health. Additionally, you highlighted the gap that your study is trying to fill: there are few studies that describe differences in biodiversity between urban and rural lakes! Your background information also introduced to me the various ways a scientist can measure biodiversity, which helped me interpret your results. 

• In future versions of your manuscript, I encourage you to include some more information on these diversity indices. You provided a nice example of how researchers discovered what can affect biodiversity. However, when I read about these different indices, I wondered how Shannon’s H, Shannon’s E and alpha differ. Providing a brief description of how these are different would have helped me better interpret your results and understand why you used Shannon’s H and Shannon’s E in your study, but not alpha. In addition to providing important background information for your readers, your Introduction should also include information that explains why you chose specific measures to answer your research question. 

3) What are the strengths of their hypothesis? How could it be improved?

• Your hypothesis is clear and was easy to find in both the Introduction and Summary. Your hypothesis was also worded similarly between the Introduction and Summary, which was helpful because this reminded me of your main goals throughout the manuscript! However, one thing I think you could improve for future drafts is to define what you mean by “evenness”. This is a term that some readers might not be familiar with, so introducing what this term means earlier in your Introduction can help your readers better understand your hypothesis and scientific question. \

4) What are the strengths of the experimental design? Can you think of accessible experiments or analysis that would help the authors strengthen their study? 

• Your experimental design was well thought out and described in your methods. However a few questions popped up while reading about your experiment. For example, did you visit each lake during the same time of day every time? Did you look at a different time each day to try and account for species that might only come out at certain times of day? This would be interesting to know so I could understand if the time of day could have affected your results. 

• In addition, without statistical analysis, you cannot completely exclude the possibility that the data you found for your urban lakes are actually different from your rural lakes. I encourage you to read over our Statistics Guide and talk with your mentor about if this is something you’d like to do for future versions of your manuscript. Scientists often use statistics to support their observations and convince readers their results are significant. Statistics can also reveal relationships and patterns that you may not see when just looking at averages or totals. Including these statistics will further convince your readers of the arguments that you are making. 

• Specifically, scientists usually calculate Shannon’s E and Shannon’s H for each time a place is sampled, which is something you can do with your study. Then, you would calculate the mean and standard deviation of these indices for each lake, and use them in your tables and graphs. You can also use these individual observations as the foundation for your statistical analysis. For example, you could test whether urban or rural lakes had more diversity (using an unpaired t-test), or whether the numerical distance from Cleveland correlates with biodiversity (using linear regression, for example).

• You can also try looking at your data again for more trends. For example, was there a relationship between biodiversity and the lake depth or area? What about between biodiversity and the temperature or weather for each observation? You also mention that some of the rural lakes were in agricultural areas and that this can impact biodiversity. For future studies, you could consider measuring the plant biodiversity of each site, too, to see if lakes with less plant diversity also hosted less diverse animal communities. 
  

5) What are the successes and the areas for improvement in the Discussion? Consider factors such as how clearly results are summarized, how well the results support the conclusions, how key takeaways are communicated, how limitations or next steps are discussed, etc.  

• Your Discussion did a nice job of explaining multiple factors that could affect your results and using other studies to interpret your findings. There were several suggestions for future studies, which show the level of thought you put into thinking about what your results mean. 

• In your Discussion, you could also talk more about the limitations of your experimental design. You did a great job of thinking about outside factors that could have affected your results, but what about how you did your experiments? In your Methods, you indicated that you visited the lakes three different times over the course of two months. Did you complete your 90-minute observations around the same time of day? Was the weather the same every day? This could have affected your results and including this information would help your readers understand your results in the broader context. 

• I also encourage you to spend some more time talking about why your hypothesis wasn’t supported. Was there something specific about the urban lakes that could explain your results? Right now, your Discussion describes how different factors could affect different aspects of biodiversity. However, your Discussion doesn’t clearly address your findings and what they mean. I encourage you to consider adding this to future revisions. What to include in a Discussion can be tricky, so if you need inspiration, I encourage you to read the other preprints published on eiRxiv  as well as articles published to the Journal of Emerging Investigators. 

6) What changes can the authors make to improve how they are verbally or visually communicating their scientific knowledge, results, and reasoning? Could someone who has never heard of this topic understand the main message of the paper?

• A general comment is that your figure caption should have enough information that a reader would be able to understand what is being presented without having to read your paper. Many scientists consider figures the heart of a paper, and so they may spend most of their time on looking at the figures.  You do a nice job of explaining the calculations and what these values mean. However, you also want to make sure that you add a brief summary of the methods on how you collected the data to calculate your biodiversity indices. I encourage you to review our Figure Caption guide for some example figure captions. 

• Since the focus of your paper is on comparing rural lakes and urban lakes, it would be helpful to note on Figures 2 and 3 which lakes you considered urban and which lakes you considered rural. Please also make sure to label your y-axis on your graphs! On Figure 2, your y-axis should be labeled as “Shannon's" H”. For Figure 3, your y-axis should be labeled as Shannon’s E”. All of these will help your readers interpret your data. 

• For Table 1, it would help to add another column that indicates whether the lake was classified as rural or urban. Then, in your figure caption, you could explain what criteria you used to determine whether a lake was rural or urban. 

• For Table 2, it might help to break down the unique species by type of species. For example, how many unique birds did you see? What about unique mammals or insects? This would also help readers think deeper about your data and may also reveal some interesting patterns to you! 

• Since you present Shannon’s H and Shannon’s E for each lake in Figures 2 and 3, I would also consider whether Table 3 provides new information that is different from Figures 2 and 3 - does it add  important, additional information for readers? If not, it is not necessary to keep, then you can remove this figure.