The Rusty Crayfish By: Vlad Spirkov, Michael Tsimidis & Matthew Bondi Ecology STSE Changes in Stability of Ecosystems

-Rusty Crayfish are a frightening problem to the Great Lakes ecosystems -Affect all/ most of the ecosystem’s food web -Affects tourism and fishing in the great lakes -Rusty Crayfish are competing with the native crayfish species found in the Great Lakes, which harms the native population -Rusty Crayfish are also increasing the population of some predators, such as Bass, which can have both positive and negative consequences -There are various ways to mitigate the spread of Rusty Crayfish into further areas of the great lakes INTRODUCTION

-Name: Rusty Crayfish or Orconectes rusticus -Rusty Crayfish are an aquatic species of crayfish with a dark red/brown rusty colour -Where: The rusty crayfish were first discovered in the Ohio River Basin and quickly spread at an alarming rate into Kentucky, Indiana, Tennessee, Illinois, and the water areas of many other states in the Great Lakes section of America (see below). They have also managed to spread from the USA into Ontario. -How they grow and reproduce: Mating happens between female and male Rusty Crayfish. The female crayfish will lay around eggs, which hatch in 3-6 weeks, depending on the water temperature. SCIENTIFIC PERSPECTIVE-Matthew

Rusty Crayfish are multiplying fast, and there is currently no effective or proven way to reduce rusty crayfish population without harming other species. Some ideas for how to reduce crayfish are: -Having a larger population of bass and sunfish may help rusty crayfish to be less invasive -Putting many traps into areas with high Rusty Crayfish populations -Introduce aquatic species that will lower Rusty Crayfish numbers -Spread awareness to reduce introduction of rusty crayfish into other areas TECHONOLOGICAL PERSPECTIVE- Matthew

Impact On Humans: Ecological Impact 1) Rusty Crayfish eat an extensive quantity of aquatic vegetation -Destroys nursery grounds for bass and other fish species living there -Displaces native crayfish species from sheltered areas into vulnerable areas, which causes predators to kill the native species more easily 2) Rusty Crayfish compete with native crayfish species which makes it more difficult for native species to survive -Reduces population of native species Economical Impact 1)Banning the use of Rusty Crayfish as bait in habitats that do not already have them, cause economic pain to bait merchants using them as merchandise -Merchants selling baits therefore have to buy other, more expensive alternatives which cause further financial loss 2)Hurt market for bass due to declines in bass spawn 3)Extermination of rusty crayfish is expensive and is not always effective Impact on Tourism 1)Rusty Crayfish destroy nursery grounds of economically valuable fish species such as bass -Reduces population of these species 2)Reduces the amount of anglers who fish in those waters (No fish to catch=No fish to sell=No money) SOCIETAL PERSPECTIVE- Michael

How Rusty Crayfish can be Controlled by Humans: Impact On Health 1)Harms its new food web -Kills predators eggs -Competes with native crayfish for food -Puts native crayfish into vulnerability Mechanical 1) Banning use or transportation of Rusty Crayfish as bait 2) Prevention is the best method for dealing with Rusty Crayfish -Barriers or nets that can prevent the further spread of Rusty Crayfish -Traps are a simple, yet effective way of removing small quantities of the Rusty Crayfish Chemical 1) Adding chemicals into aquatic vegetation to change it’s odour -Turns away Rusty Crayfish into believing that the vegetation is not editable1 Biological 1) Augmenting predators -Protecting bass’s eggs by putting them into an incubator then releasing them back into their natural ecosystem SOCIETAL PERSPECTIVE Contd. - MICHAEL

Effects on Native Crayfish. The Rusty Crayfish Displaces the Native Crayfish. The Rusty Crayfish are better hiders then Native Crayfish making them more vulnerable to predators. The Rusty Crayfish have bigger claws therefore they can protect themselves from predators better meaning that the Native Crayfish are a bigger pray for predators. Control of the species can restore the Native Crayfish. Environmental Perspective-Vlad

Effects on the General Food We b. The Rusty Crayfish eat large amounts of aquatic plants witch indirectly reduces natural habitats for other species. When removed from areas certain areas, species effected by them have had their population increased significantly. Reduce population of some other fish species. Potential Impacts. The Rusty Crayfish can easily remove other crayfish from their habitat and they can compete better with the limited food resources. Other crayfish eat aquatic plants the Rusty Crayfish eat even more due to their higher metabolic rate, resulting in even less food for other species. ENVIORNMENTAL PERSPECTIVE-Vlad

Conclusion Rusty Crayfish are destroying our Great Lakes ecosystem and the species living in them 1) Impact all aspects of life -Impacts economically, ecologically, and affects tourism and health If Rusty Crayfish are not controlled properly there could possibly be tremendous consequences -Native Crayfish may become endangered in some areas of the Great Lakes -Economical losses in businesses situated in that region If there is a will to prevent further spread, then there is a way -Anglers who catch Rusty Crayfish must kill them -More traps and nets to catch Rusty Crayfish also alleviates some of the difficulty in this battle to stop the spread.