Management Information
Preventative measures: Educating anglers, crayfish trappers, bait dealers, teachers, and the general public about the ecological threats posed by Orconectes rusticus will help reduce the risk of its spread to new areas (Olden et al, 2006). Monitoring boat docks, fishing areas, or setting up check points in order to halt the use of O. rusticus as bait may also be effective in preventing their establishment (Keller et al, 2008). Regulations in both Minnesota and Wisconsin now make it illegal to introduce O. rusticus into any waters. In Minnesota, it is illegal to sell live crayfish as bait and a Department of Natural Resources permit is required to commercially harvest or culture crayfish (Gunderson, 2008). Regulations regarding O. rusticus in other states differ depending on state and vector. Many states have regulations that specifically targeted the invasive rusty crayfi sh. However, these regulations were enacted reactively only after rusty crayfi sh had become established in the state. The lack of regulatory consistency among the Great Lakes jurisdictions is creating a multiple weak links problem and making success unlikely in efforts to slow the spread of O. rusticus and other invasive species throughout the region (Peters & Lodge, 2009). In Wisconsin, it is illegal for anglers to possess any crayfish. In Pennsylvania it is illegal for anglers to possess, aquarists to raise, and bait dealers or pet traders to sell O. rusticus. In Ohio, it is illegal to move crayfish from a natal lake in or for aquarists to rear O. rusticus. In Michigan, it is illegal for bait dealers and pet traders to sell and for aquarists to rear O. rusticus. In Illinois, it is illegal for anglers to possess, bait shops to sell, and for aquarists to rear O. rusticus. In Ontario, it is illegal move crayfish from a natal lake and for bait dealers to sell crayfish (Peters & Lodge, 2009)
Physical: Intensive harvest will not eradicate or control crayfish, but may help reduce adult populations and minimize some impacts.
Some researchers have suggested that nuisance populations of rusty crayfish are the result of poor fishery management and that by restoring a healthy population of bass and sunfish, O. rusticus would be less disruptive in some lakes. Populations of Orconectes rusticus may be reduced by trapping or fish predation. Although neither practice may provide eradication both have been found to be effective means of reducing negative impacts and decreasing population sizes of O. rusticus (Hein et al, 2006; Hein et al, 2007). The use of electric fences along with hand removal in experimental plots was also found to reduce densities of O. rusticus and may have implications for macrophyte restoration efforts (Peters et al, 2008). The control of a rusty crayfish population in Sparkling Lake, an isolated lake in northern Wisconsin by trapping adult crayfish and restricting fishing, thereby increasing fish populations and predation on small crayfish was found to effectively reduce O. rusticus populations there. To protect and enhance populations of rusty crayfish predators, the Wisconsin Department of Natural Resources instated strict regulations on smallmouth bass. Also, wire minnow traps with an enlarged (3.5 cm diameter) opening were baited with 4 to 5 frozen smelt (8–13 g each), set 1–2 m deep at ~10 m intervals, and used to capture O. rusticus. Over a 3 year period, traps and predatory fishes removed substantial portions of the rusty crayfish population. Because more crayfish were vulnerable to and removed by fish predation than by trapping, fish predation caused a larger decline in the population growth rate. However, trapping removed crayfish with the highest reproductive value and caused the largest decline in population growth rate per individual crayfish removed. Researchers estimated that traps and fish removed a total of 1,212,148 individuals and 1212 kg of crayfish over three years of removal. Together they removed approximately 55% of the population in 2003 (Hein et al, 2006). Removal trapping catch rates declined by 95% over the last 4 years of removal from Sparkling Lake (Hein et al, 2007). Trapping was found to be most effective on cobble substrates (Hein et al, 2006). A similar trapping study of O. rusticus found that captured individuals left in traps excluded uncaptured individuals from entering traps (Ogle & Kret, 2008). The experimental use of electric fencing along with hand removal were able to significantly reduce O. rusticus densities in electric plots compared to non-electric control plots in Lake Ottawa, located in the Ottawa National Forest, Michigan. Macrohpytes Potamogeton richardsonii and Elodea canadensis were eliminated within a matter of days in the control plots and within 3 wk in the electric plots (Peters et al, 2008). Chemical: There are means of chemical control for Orconectes rusticus. However, none currently registered have been found to selectively kill O. rusticus without effecting other species of crayfish (Gunderson, 2008). An evaluation of several potential chemical controls found a synthetic pyrethroid (Baythroid) at 25 .mu.g/L was most effective and produced a complete kill of crayfish in the pond and was also the most selective for crayfish in laboratory tests (Bills & Marking, 1992). High, sub-lethal concentrations of metolachlor (80 ppb) may interfere with the ability of O. rusticus to receive or respond to social signals and thus affect certain agonistic behavior, implications may be useful to its management (Cook & Moore, 2008). 
Location Specific Management InformationIllinois
It is illegal for anglers to possess and bait shops to sell Orconectes rusticus in Illinois. It is also illegal for pet traders to sell and aquarists to rear O. rusticus (Peters & Lodge, 2009). Michigan
It is illegal for bait dealers and pet traders to sell Orconectes rusticus in Michigan. It is also illegal for aquarists to rear them (Peters & Lodge, 2009). Ohio
It is Illegal to move crayfish from a natal lake in Ohio and for aquarists to rear (Peters & Lodge, 2009). Ontario
It is Illegal move crayfish from a natal lake and for bait dealers to sell crayfish in Ontario. It is also illegal for aquarists to rear Orconectes rusticus (Peters & Lodge, 2009). Pennsylvania
It is illegal for anglers to possess, aquarists to raise, and bait dealers or pet traders to sell Orconectes rusticus in Pennsylvania (Peters & Lodge, 2009). Wisconsin
It is illegal for anglers to possess any crayfish in Wisconsin (Peters & Lodge, 2009). The control of a Orconectes rusticus population in Sparkling Lake, an isolated lake in northern Wisconsin by trapping adult crayfish and restricting fishing, thereby increasing fish populations and predation on small crayfish was investigated. To protect and enhance populations of crayfish predators, the Wisconsin Department of Natural Resources instated strict regulations on smallmouth bass. Over a 3 year period, traps and predatory fishes removed substantial portions of the rusty crayfish population. Because more crayfish were vulnerable to and removed by fish predation than by trapping, fish predation caused a larger decline in the population growth rate. However, trapping removed crayfish with the highest reproductive value and caused the largest decline in population growth rate per individual crayfish removed. Researchers estimated that traps and fish removed a total of 1,212,148 individuals and 1212 kg of crayfish over three years of removal. Together they removed approximately 55% of the population in 2003. Wire minnow traps with an enlarged (3.5 cm diameter) opening were baited with 4 to 5 frozen smelt (8–13 g each) and set 1–2 m deep at ~10 m intervals. Trapping was found to be most successful on cobble substrates (Hein et al, 2006). Removal trapping catch rates declined by 95% over the last 4 years of removal (Hein et al, 2007).
Wyoming
A population of Orconectes rusticus that was illegally stocked in Wyoming was reportedly eradicated by the Wyoming Game and Fish Department (USGS, 2010).
Management Resources/Links
2. Bills T. D; Marking L. L., 1992. Control of Nuisance Populations of Crayfish with Traps and Toxicants. Progressive Fish-Culturist. 50(2). 1988. 103-106. 4. Byron, Carrie J.; Wilson, Karen A., 2001. Rusty crayfish (Orconectes rusticus) movement within and between habitats in Trout Lake, Vilas County, Wisconsin. ournal of the North American Benthological Society. 20(4). December, 2001. 606-614. 5. Hein, Catherine L.; Roth, Brian M.; Ives, Anthony R.; Vander Zanden, M. Jake, 2006. Fish predation and trapping for rusty crayfish (Orconectes rusticus) control: a whole-lake experiment. Canadian Journal of Fisheries & Aquatic Sciences. 63(2). FEB 2006. 383-393 6. Hein, Catherine L.; Vander Zanden, M. Jake; Magnuson, John J., 2007. Intensive trapping and increased fish predation cause massive population decline of an invasive crayfish. Freshwater Biology. 52(6). JUN 2007. 1134-1146. 7. Keller, Reuben P.; Frang, Kristin; Lodge, David M., 2008. Preventing the spread of invasive species: Economic benefits of intervention guided by ecological predictions. Conservation Biology. 22(1). FEB 2008. 80-88. 8. Kluza, Daniel A. 2004. Emerging threats: Potential geographic distributions of temperate aquatic invasive species. In Abstracts: 13th International Conference on Auatic Invasive Species, September 20-24, 2004. Lynch West County Hotel, Ennis, County Clare, Ireland.
Summary: Using a computer based model to help predict possible global distributions of invasive species. 9. Momot, Walter T., 1992. Further range extensions of the crayfish Orconectes rusticus in the Lake Superior basin of northwestern Ontario. Canadian Field-Naturalist. 106(3). 1992. 397-399. 10. Ogle, Derek H.; Kret, Lori, 2008. Experimental evidence that captured rusty crayfish (Orconectes rusticus) exclude uncaptured rusty crayfish from entering traps. Journal of Freshwater Ecology. 23(1). MAR 2008. 123-129. 11. Peters, Jody A.; Lodge, David M., 2009. Invasive Species Policy at the Regional Level: A Multiple Weak Links Problem. Fisheries (Bethesda). 34(8). AUG 2009. 373-381 12. Puth, Linda M.; Allen, T. F. H., 2005. Potential corridors for the rusty crayfish, Orconectes rusticus, in northern Wisconsin (USA) lakes: Lessons for exotic invasions. Landscape Ecology. 20(5). JUL 2005. 567-577. 13. Rosenthal, Sadie K.; Stevens, Samantha S.; Lodge, David M., 2006. Whole-lake effects of invasive crayfish (Orconectes spp.) and the potential for restoration. Canadian Journal of Fisheries & Aquatic Sciences. 63(6). JUN 2006. 1276-1285. 14. Taylor, Christopher A.; Redmer, Michael, 1996. Dispersal of the crayfish Orconectes rusticus in Illinois, with notes on species displacement and habitat preference. Journal of Crustacean Biology. 16(3). 1996. 547-551. 15. Usio, N.; Nakata, Kazuyoshi; Kawai, Tadashi; Kitano, Satoshi, 2007. Distribution and control status of the invasive signal crayfish (Pacifastacus leniusculus) in Japan. Japanese Journal of Limnology. 68(3). DEC 2007. 471-482. Results Page: 1
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