Does the presence of aquatic vegetation help us understand variation in fish communities between the archaeological record and modern samples?

Background/Question/Methods

Through the use of archaeological and modern ecological datasets, we explored the relationship between fish communities and the presence of vegetation within the Upper Mississippi River System (UMRS). Researchers suggest that aquatic vegetation was present during archeological times throughout the UMRS. Today, submersed aquatic vegetation (SAV) is prevalent in the upper reaches of the UMRS, but nearly absent in the lower reaches (i.e. below Lock and Dam 19). We hypothesized that fish communities represented in archaeological collections would be more similar to the modern day upper UMRS than the lower UMRS. We compared the frequency of occurrence of fish communities represented in archaeological collections and modern samples.

Results/Conclusions

The modern samples were significantly different from all archaeological collections. Nevertheless, there was overlap between some archeological collections and the upper reaches of the UMRS which provides partial support for our hypothesis. We predicted that 12 taxa that use aquatic vegetation for spawning would have a greater frequency of occurrence in the upper reaches relative to the lower reaches; however, only six taxa aligned with our expectations.