Evidence of Asian carp spawning above a key choke point in the Mississippi River: Data

Bighead Carp, Silver Carp and Grass Carp (collectively Asian carp) were introduced to North America in the 1960s and 70s and have established in the lower Mississippi River basin. Previously published evidence for spawning of these species has been limited in the upper Mississippi River to just below Dam 22 (near Saverton, MO). In 2013 and 2014, we sampled ichthyoplankton at 18 locations in the main stem of the upper Mississippi River from Dam 9 through Dam 19 and in four tributary rivers that empty into the Mississippi River (Des Moines, Skunk, Iowa and Wisconsin Rivers). We identified eggs and larvae using morphological techniques and then used genetic tools to confirm species identity. The spawning events we observed often included more than one species of Asian carp and in a few cases included eggs that must have been derived from more than one upstream spawning event. The upstream extent of genetically confirmed Grass Carp was Pool 12, while Bighead Carp and Silver Carp were observed in Pool 16. In all these cases, ichthyoplankton likely drifted downstream for several kilometers prior to collection. As has been observed elsewhere, no eggs or larvae were collected prior to water temperature reaching 17°C and discharge was usually high when eggs or larvae were observed. Several major spawning events were observed in 2013, but not in 2014. Although reproduction appears to be occurring for all three of these species above Dam 19, the recruitment success of these populations is unknown.

[
  "010:12"
]

[
  "geospatial"
]