Gavin's Point Dam, phytoplankton, bigheaded carps, Hypophthalmichthys spp, Missouri National Recreational River
Aquaculture and Fisheries | Biology
Bigheaded carps (Hypophthalmichthys spp., formerly known as Asian carps) escaped from aquaculture facilities and dispersed throughout the lower Mississippi River during the 1980's. Unprecedented flooding in 2011 accelerated the migration of bigheaded carps over low-head dam structures and throughout the 59-mile reach of the Missouri National Recreational River (MNRR) downstream of Gavins Point Dam. Bigheaded carps have recently drawn considerable ecological attention by directly exploiting the basal aquatic food web while competing with trophic niche overlaps of native planktivorous fishes. Although a small minority of studies have measured basal food web effects of bigheaded carps in the Mississippi River Basin, none to our knowledge have compared historical, pre-invasion phytoplankton abundance data from throughout the Missouri River Basin to present-day phytoplankton abundance sample data. We plan to compile, digitize, and analyze several plankton datasets collected over the last seventy years from the Missouri River Basin. Additionally, we intend to replicate sampling methods and sampling sites outlined in the first Missouri River Basin plankton survey performed by Kenneth E. Damann in 1950. Study sites will include the presence or absence of bigheaded carps. Samples will be enumerated and identified to the lowest practicable taxon. Hypothesis 1 will pose the question of whether the sites that were historically abundant remained abundant and determine if similarities in plankton densities exist across sites. Hypothesis 2 will pose the question of whether differences in plankton abundance or community structure between 1950 and today are greater, fewer, or similar in the presence versus absence of bigheaded carps. By analyzing historical and modern data we hope to quantify the temporal effect of bigheaded carp on phytoplankton resources.
Dunbeck, Ryan, "Changes in Phytoplankton Abundance and Community Structure of the Missouri River Basin Over 70 Years" (2020). IdeaFest. 15.