February 15-18, 2009 Washington State Convention Center Seattle ...

METHYLMERCURY CONCENTRATIONS FOUND IN WILD AND FARM RAISED
PADDLEFISH IN KENTUCKY
Richard J. Onders, Siddhartha Dasgupta, Steven D. Mims and Deke T. Gundersen
Aquaculture Research Center
Kentucky State University
Frankfort, KY 40601 USA
rick.onders@kysu.edu
Kentucky is one of 18 states with statewide fish consumption advisories due to mercury contamination. These advisories are
renewed annually; however, they are based on limited and intermittent data. In addition, a more restrictive advisory is issued
for paddlefish consumption. We compared mercury levels in the muscle tissue of paddlefish from two wild sources: Ohio River
and Lake Cumberland, and from two farmed sources (polyculture with catfish and reservoir ranching) with the advisory levels.
We also compared these levels with those typically present in species popular with consumers, both freshwater and marine.
The results will be presented.
RESERVOIR RANCHING OF PADDLEFISH Polyodon spathula
Richard J. Onders and Steven D. Mims
Aquaculture Research Center
Kentucky State University
Frankfort, KY 40601 USA
rick.onders@kysu.edu
Reservoir ranching is a sustainable extensive fish production method that is practiced worldwide.
It is based upon artificial propagation and stocking of the desired species, with grow out entirely dependent on the natural productivity
of the reservoir. Therefore, it is best suited to species which feed low on the food chain and have potential for rapid
growth. The paddlefish Polyodon spathula is such a species as it is a zooplanktivore that is known to grow rapidly. In addition,
paddlefish roe is valuable as a source of black caviar.
In the US, there is a history of commercial fishing in large reservoirs, primarily for such species as catfish Ictalurus spp.,
buffalo Ictiobus spp. and common carp Cyprinus carpio. However, state agencies have restricted these fisheries over several
decades because of the perception that they interfere with recreational fishing. This has produced a culture of opposition to
reservoir ranching in the US, as stocking fish for commercial harvest would reverse the decline of inland fisheries, and this
would be viewed as undesirable by recreational fishing groups and state fishery managers.
In 2006, under pressure from state legislators, the Kentucky Department of Fish and Wildlife Resources enacted regulations
allowing reservoir ranching of paddlefish in qualifying municipal water supply reservoirs. Developments before and since
enactment of these regulations will be reviewed.
2