Science Advisory Report 2009/078

Science advice from the risk assessment of the invasive bloody red shrimp (Hemimysis anomala) in Canada

Summary

• The bloody red shrimp (Hemimysis anomala) is one of the recent non-native species to be discovered in the Great Lakes. It is believed to have been introduced through ballast water.
• Hemimysis anomala is a species of mysid native to the Ponto-Caspian region, first identified in the Great Lakes in 2006, though anecdotal evidence suggests it may have been present since 2002.
• An ecological risk assessment was conducted to evaluate the risk from H. anomala in Canada, focusing on two geographic areas: the Great Lakes and Ontario inland lakes.
• H. anomala presents a moderate to high risk to the Great Lakes. Persistence over multiple years at some sites suggests it can survive, is established and has already spread within the Great Lakes to lakes Michigan, Erie and Ontario.
• The impact of a locally established population could be low to moderate, but with some chance of high impacts, particularly if the location is an important nursery for fishes.
• Widespread establishment of H. anomala has the potential to cause food web disruptions, as well as alter nutrient and contaminant cycling.
• H. anomala seems to prefer structure and are found most consistently next to docks. Activities around docks that will pick up and move water likely represent a higher risk of secondary transport of H. anomala. Transportation of live bait is one such activity.
• There is a high probability that H. anomala will spread to inland lakes. While uncertainty is high, if H. anomala were to become established in inland lakes it would likely impact food webs. The probability that H. anomala will become widespread in inland lakes will depend on which inland lakes are initially invaded.
• Understanding the factors that will control the abundance of H. anomala will be important for predicting the probability of establishment. Understanding what may limit H. anomala abundances will also help to refine estimates of potential impacts.
• Additional efforts should focus on detecting H. anomala and developing standard sampling methods specific to this organism. Monitoring for H. anomala, which began in 2007, will be expanded in order to assess H. anomala presence in the remainder of the Great Lakes.

Complete document (PDF, 113 KB)

Accessibility Notice

This document is available in PDF format. If the document is not accessible to you, please contact the Secretariat to obtain another appropriate format, such as regular print, large print, Braille or audio version.