Asian Carp Action Plan

USFWS

Silver Carp (Hypophthalmichthys molitrix)

In 1996 an Asian carp was reported for the first time on the St. Croix River. This was a concern because Asian carp grow to large sizes (50-110 lbs.) and eat up to 20% of their body weight daily, possibly out competing native species for food or habitat resources. These big eaters could unravel the food web by consuming plankton needed by smaller fish that feed sport fish, such as bass and walleye. Silver carp can also leap really high out of the water, appearing to almost fly. They have been known to injure people if they land on them.

Recent efforts (in 2011), aimed at detecting species of Asian Carp on the St. Croix River, unfortunately suggest their presence for several miles downstream of the hydroelectric dam at St. Croix Falls, Wisconsin.  Asian carp were detected using a new technique that analyzes water samples for traces of fish, such as body fluids, scales, etc.  Results point to the Asian carp species called silver carp (known as the flying carp for their leaping ability) as the fish in this section of the river.  To date, no physical specimen of silver carp has been found in the St Croix. (MN DNR Press Release)

On June 28 and June 29, 2011, eDNA Solutions, Inc. conducted environmental DNA (eDNA) testing in the St. Croix and Mississippi rivers for Black, Bighead and Silver carp. Testing on the St. Croix occurred from below the dam at Taylors Falls and continued 4.3 miles downstream. The testing on the Mississippi covered a reach from immediately below low Lock and Dam No. 1 (Ford Dam) to the mouth of the Minnesota River about 3.5 miles downstream. See the report, eDNA Surveillance of Asian Carp on the St. Croix and Mississippi River (PDF, 500kb) and sampling map for detailed findings.

(Funding for the study has been provided by the Mississippi River Fund and St. Croix National Scenic Riverway Fund of the St. Croix Valley Foundation.)

The Minnesota DNR has now begun to confirm the test results by fishing, netting and "electrofishing" for silver carp in the area of positive test results. Together, the Riverway and other wildlife agencies will be working to confirm the presence of Asian carp (MN DNR Press Release 8.22) and the best plan to prevent or decrease their impact. In November 2011 an Action Plan was finalized by the involved agencies and is available for review.

 

Deborah Rose/MN DNR

NPS biologist, Byron Karns, collects water samples for testing

In mid-September additional water samples were collected and sent to eDNA Solutions, Inc. to conduct environmental DNA (eDNA) testing in the St. Croix, Mississippi and Minnesota rivers for Bighead and Silver carp. Testing on the St. Croix occurred both above and below the dam at St. Croix Falls, WI. The testing on the Mississippi covered a reach from immediately below low Lock and Dam No. 1 (Ford Dam) to the mouth of the Minnesota River and the Minnesota River collections were downstream from the Cedar Ave bridge. Initial reports for the Mississippi have been received and indicate a presence of silver carp. (MNDNR Press Release 10.20) Results for the Mississippi above the Coon Rapids Dam also indicate the presence of silver carp.(MNDNR Press Release12.8) Results for the St. Croix River again show the presence of silver carp below the dam in St. Croix Falls. The results from 32 samples above the dam were negative. Other samples should be available within the next two months and will be reported when received.

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Deborah Rose/MN DNR

Filtering and preparing the river samples for shipment

The St. Croix National Scenic Riverway is working very closely with our sister park, the Mississippi National River and Recreation Area to address the threat posed by all Asian carp species.  Together, these two National Park Service units are taking a regional approach in creating an action plan (along with many partners, including the Minnesota Department of Natural Resources) to stop or slow the spread of these invaders.  We intend to do the following:

• 1)   Continue to monitor using environmental DNA techniques and fish collection to determine the breath and density of the invasion.
• 2)   Search for ways to remove these fish from the rivers.
• 3)   Identify physical and behavioral barriers to these fish and work with our partners to use them.
• 4)  Support ongoing research to identify repellants, attractants, or lethal controls of Asian Carp.

    To learn more about Asian carp. Visitors to the Riverway who catch or see Asian carp should report their sightings to the DNR or Riverway.

Additional Information

• 2011 Obama Administration Asian Carp Control Strategy Framework
• Army Corps of Enginners: Great Lakes and Mississippi River Interbasin Study
• Asian Carp Control, Regional Coordinating Committee (asiancarp.org)
• Minnesota DNR: Preventing the Introduction of Asian Carp into Minnesota
• Minnesota DNR: Minnesota's Watershed Basins
• Wisconsin DNR: Asian Carp Control Efforts
• USGS: Asian Carp Invasion of the Upper Mississippi River System (2000)