The Wastewater Treatment Plant Story: Part 2

This week I got started on chapter 2 of my dissertation, which examines how environmental characteristics are related to nematode communities in St. Andrew Bay. The words 'nematode communities' describe the diversity of the nematode members living in the bay system. This part of my work will take the majority of the summer, so I will be explaining the research in as much depth as possible so that you understand what I am doing and what I hope to learn. I'll use this week's blog to explain how I decided on this work, what it can tell us, and the different stages involved in this portion of my research.

Originally I was interested in assessing how nematode communities changed due to variations in microplastics abundances in the St. Andrew Bay system. This was the work I started more than two years ago and recently finished. However, partway through the planning and research process, I decided (with help) that due to the amount of environmental variability in the system, I likely wouldn't be able to make strong claims about how microplastics specifically changed nematode community structures. Similarly, there are some extra pollution sources in St. Andrew Bay, and while those sources are unlikely to cause high levels of microplastic pollution, they are certain to introduce chemical contaminants that alter the environmental quality and thereby change nematode community structures. By the time I decided that the nematode work wouldn't be feasible, I had already extracted nematodes from all of my sediment samples and counted most of the samples, which can be a lengthy process. This work was not all for naught, however.

The St. Andrew Bay system is exceptionally unstudied, and the most recent estimate of nematode species in the system comes from a 2002 study of the total biodiversity of the bay area. There may, however, exist differences across the bay that contribute to different species existing in the various waterways. Pollution is often a driver that influences nematode community structure, and since I have two waterways that host wastewater treatment plants, I decided (with help, again) to assess the diversity of nematode communities in the system at areas of wastewater treatment outflow compared to non-polluted sediments. By understanding the communities that exist at both polluted sites and areas free from direct contamination, I can then assess which nematode species may be tolerant of microplastics in future experimentation.

This summer, I will be counting the final set of nematodes from my previous work and I will create more slides so that I can spend the majority of my time identifying nematodes taxonomically. While some animals are easy to identify to the lower taxonomic levels (Genus and Species) based on sight (take sharks, for instance), nematodes are more difficult and require more patience and precision because there are much smaller and may look similar. Throughout the identification process, I hope to provide you with good pictures identifying key differences between nematodes, and to talk about why some of their body parts look the way they do.

In the meantime, enjoy this picture from this week's work, where I had to count an entire sample of nematodes that didn't absorb the dye. Can you see any animals in this picture?

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