The poster provides an interesting and compelling glimpse of the potential for baseline DOM observations for long term ecologic monitoring. The video is not compelling. How do you plan to distinguish changes due to DOM from turbidity changes due to sediment? Why only measure in summer, you have many northern lakes where little information is available in winter, could this not be a baseline that could show even more change if for example ice cover duration declines and winter turnover is altered?

Excellent job Nicole, Patricia, Deshawn, Margaret, and Jennie! I like the clear presentation, and especially the way you integrated perspectives of those at both Miami and Kent working on diverse systems. I look forward to how your results are integrated this summer.

Hello,

We are measuring DOM change with two methods. First, we are collecting bi-weekly samples to analyze on a UV-visible light spectrometer. Second, we have a permanent CDOM (chromophoric dissolved organic matter) sensor attached to the buoy. Both of these measurement methods operate on the principle that CDOM absorbs light in the UV spectrum and then fluoresces blue light. Based on the wavelength of fluoresced light we can draw conclusions about the source (terrestrial versus aquatic) of the DOM.

We are measuring turbidity with a sensor attached to the buoy. It operates by emitting visible light, then measuring the amount of light that back scatters at a 90 degree angle.

Using both sets of CDOM data we plan to look at changes in the source of CDOM data over our sampling period. We anticipate that there will be a positive correlation between higher quality DOM (more terrestrial) and turbidity (a result of run-off events) in our systems.

We are limited to taking summer measurements because of the danger ice presents to our buoys. In many of our sampling sites (particularly the reservoirs) we also wouldn’t have access to the buoy for extended periods of time because the lakes don’t freeze solid enough to travel on and, if we could reach the buoy, the sensors would be frozen into the lake. Although winter sampling could add an interesting component to our study, for now we are limited to summer only.

Thanks for your comments,
Nicole

Hi,

The buoys have been out on some of the lakes for about a month now or will be out within the next few weeks. We should be able catch a number of large storm events in these periods, even if we are not able to catch all of the big spring storms or even the largest storm events.

We have also been able to test the efficacy of our index over different time periods (weeks to months to seasons) and we have found that monthly samples reflect large precipitation events eliminating the need to take hand samples directly after heavy rains.

Nicole

Very timely topic on climate change. I enjoyed the inter-college collaboration from Miami and Kent State. I would like to see your results of your data collection. I was wondering about sampling only in the summer, and I read your response to a previous question.

Hello everyone,
You did a good job explaining your research project. It sounds interesting and should provide useful information. You also did a good job explaining how you will gather the lake/terrestrial DOM data (a video of a sensor buoy would have been helpful, however).

Since you are comparing terrestrial versus autochthonous inputs, could you also explain how you determine periods when there are more runoff inputs? – Are you using data from nearby river level sensors?

Nice job guys!