Thu, Aug 05, 2021:On Demand
Background/Question/Methods
Available data evidencing fish harvest and community trends in the Upper Mississippi River System (UMRS) may provide insights on the presence and effect of the Anthropocene in great river systems and their floodplains. We sought to investigate whether fish populations used by humans in historic periods would correlate with those used in contemporary periods – have we lost species which we once relied on, or have we largely been making use of the same species over time. By investigating fish community variation between commercial fish harvest and archaeological collections in the UMRS along with modern monitoring data we gain insight into changes in fish communities through time. We hypothesized that commercial fish harvest data would be more similar to archaeological collections than modern monitoring samples. We conducted multivariate analyses including analysis of similarity (ANOSIM) non-metric multidimensional analysis (nMDS) and SIMPER of these collections using Primer-7.
Results/Conclusions Although the commercial data and archaeological time periods differed significantly (ANOSIM P ≤ 0.005), several archaeological collections grouped with the commercial data at 85% similarity, providing partial support for our hypothesis. Commercial fish harvest in the UMRS still allows sustainable fish yields. Based on previous research and our findings, we suggest that any negative changes in fish communities in the modern-day UMRS are likely the result of other anthropogenic factors besides commercial harvest. This indicates that future studies of this kind, investigating the long-term health of fish communities, should look towards other processes occurring in the watershed aside from fisheries and harvest, like watershed management techniques in the area, recreation policies, and industrial waste policies which may be introducing harmful materials or practices into the study area.
Results/Conclusions Although the commercial data and archaeological time periods differed significantly (ANOSIM P ≤ 0.005), several archaeological collections grouped with the commercial data at 85% similarity, providing partial support for our hypothesis. Commercial fish harvest in the UMRS still allows sustainable fish yields. Based on previous research and our findings, we suggest that any negative changes in fish communities in the modern-day UMRS are likely the result of other anthropogenic factors besides commercial harvest. This indicates that future studies of this kind, investigating the long-term health of fish communities, should look towards other processes occurring in the watershed aside from fisheries and harvest, like watershed management techniques in the area, recreation policies, and industrial waste policies which may be introducing harmful materials or practices into the study area.