Student Investigator: Christopher Sullivan (M.S.)
Collaborators: Kim Bogenschutz and Jason Euchner, IDNR
Duration: May 1, 2014 to June 30, 2016
Funding Source(s): Iowa Department of Natural Resources (IDNR)
Goals and Objectives:
Goals and Objectives:
- Evaluate influence of environmental covariates on occupancy and detection probabilities of Asian Carp
- Evaluate and compare temporal (e.g., seasonal and annual) trends in Asian Carp population characteristics (abundance, distribution, size structure, condition) and dynamics (growth, mortality, recruitment) among southeast Iowa tributaries and upper Mississippi River populations
- Evaluate patterns of large-scale spatial synchrony of dynamic rates (recruitment and growth) for Asian Carp populations among Midwestern Mississippi River watersheds.
A total of 2,964 Asian Carp were collected in the Des Moines, Skunk, Iowa, and Mississippi rivers from April to October 2014/2015. The Des Moines River sites (below Lock and Dam 19 [LD19]) accounted for 99% of all Asian Carp captures, while the Skunk River (confluence site) accounted for only 0.01% of catch and only two Silver Carp were captured in the Iowa River. Silver Carp made up the majority of the catch (>97%) while Bighead Carp only comprised approximately 2% of captured individuals. Additionally, fourteen additional fish from the Des Moines River were identified as hybrid Asian Carp. Below LD19, Silver Carp ranged from 450 to 959 mm (mean = 665 mm) in length and 1.0 to 9.9 kg (mean = 2.9 kg) in weight. Bighead Carp ranged from 397 to 1110 mm (mean = 842 mm) in length and 0.7 to 13.7 kg (mean = 6.5 kg) in weight. Above LD19, only 33 Silver Carp were captured throughout the year ranging from 480 to 941 mm (mean = 829 mm) in length and 1.4 to 10.0 kg (mean = 7.1 kg) in weight. Proportional size distribution (PSD) indices suggest Silver Carp populations are of larger size structure in downstream sites compared to upstream sites while populations above LD19 are larger than populations below LD19. Additionally, age structures of both Silver and Bighead carp populations were similar across sites.
Processing of zooplankton and chlorophyll-a will continue until completed. During spring, data collected during 2014/2015 will be analyzed and summarized into publishable manuscripts.