2017 LAKE STEWARDS NEWSLETTER | 11 Predators & Prey Asian carps can eat up to 40% of their body weight in one day. Because they eat food from the bottom of the food chain (mostly algae, plants, and microscopic animals), this leaves little food for native fishes to eat. Grass Carp eat large quantities of aquatic vegetation and can decimate wetland and nearshore habitats that are important for many animals including other fish and birds. Asian carps, on average, weigh two to four kilograms (4 to 9 lbs) but some weigh up to 40 kg (almost 90 lbs). Because of their fast growth rate (they can grow up to 25 cm in just a year), Asian carps quickly outgrow potential predators. Other Interesting Facts The Common Carp, although originally from Asia as well, is believed to have come to North America through Europe in the 1800’s. This species is well-established in parts of Canada, and is not considered an Asian carp. Bighead and Silver carps have underdeveloped stomachs, which limit the amount of nutrients they can absorb. As a result, they are always eating. Silver Carp are excellent jumpers; when startled, they can jump up to 3 metres in the air. Unfortunately, this can result in serious injuries for unsuspecting boaters and other water users. Status of this Species A handful of Asian carps have been captured in Canadian waters of the Great Lakes, including one Bighead and 23 Grass carps. These fish probably escaped from areas where they were being used for aquatic plant control, or were released (intentionally or accidentally) by people. Although Grass Carp are considered to have arrived to lakes Michigan, Erie and Ontario, there is no evidence of reproduction in Canadian waters. Neither Silver Carp nor Black Carp have been found in the Great Lakes. Asian carps pose a major threat to the Great Lakes ecosystem. Because of their voracious appetite, rapid growth rate, and tendency to spread, they have the ability tooutcompetenativespecies.Thiswouldhavedevastating effects not only on the ecosystem, but also on recreational boating and fishing, as well as the commercial fishing industry. In addition, Silver Carp poses a safety threat to recreational water users. Cottagers, boaters and recreational fishers can help prevent the invasion of Asian carps by becoming familiar with identification and how to differentiate them from native species. Never use Asian carps (or any invasive species) as bait, and never transfer bait between lakes. If you think you may have caught an Asian carp, don’t return it to the water; instead, contact the Invading Species Hotline at 1-800-563-7711. For more info and links, visit: https://foca.on.ca/asian-carp/ ABOUT THE AUTHOR Becky Cudmore is the Manager for Fisheries and Oceans Canada’s Asian Carp Program, as well as the department’s Senior Advisor on aquatic invasive species. Becky has a post- graduate degree in Zoology from the University of Toronto and degrees in Biology and Environmental Science from Trent University. Becky has worked on aquatic invasive species in the Great Lakes for almost 20 years and was the recipient of the Queen’s Diamond Jubilee award for her contributions and efforts to protect the Great Lakes from aquatic invasive species. Here, she holds a Northern Pike, a native species that would be negatively impacted by Asian carps.