A “watch list” of species that pose the greatest threat to the Great Lakes is used to inform and help target monitoring efforts.

  • Non-native species are assessed to determine whether they pose a risk to the Great Lakes Basin and whether and how they might be introduced.
  • Knowing which species pose the greatest threat to the Great Lakes allows agencies and others to target limited resources toward looking for those species.
  • A regional framework for Great Lakes early detection includes a watch list of high-risk species to inform AIS early detection efforts across the Basin.

Identifying species that pose a threat to the Great Lakes is an important strategy within an early detection program because it informs what to look for, and where and how to look for them. This increases the likelihood that high-risk species are detected soon after introduction which increases the potential for a successful management response. Species risk assessments are used to evaluate species likelihood of being introduced to and surviving in the Great Lakes, their potential impact, and other risk factors. 

The species watch list below identifies species that are likely to have a high or moderate ecological and/or socioeconomic impact if they established in or spread to new locations in the Great Lakes Basin. The watch list was compiled using several regional risk assessment sources and was developed as part of the Aquatic Invasive Species Interstate Surveillance Framework for the U.S. Waters of the Great Lakes (the Framework). Species on the watch list meet the following criteria: 

  • A pathway exists that could move the species into the Great Lakes
  • The species is likely to tolerate/survive transport in the identified pathway
  • The species has a probability of being introduced through the pathway multiple times or in large numbers
  • The species is likely to be able to successfully establish, reproduce and spread in the Great Lakes
  • The species has been known to invade other areas
  • The species is likely to have a high or medium impact on ecological or socio-economic values

Fish Watch List

Species nameCommon nameCombined impact score (0-72)Cumulative pathway score (0-600)No. jurisdictions regulated (0-10)
Acanthogobius flavimanusYellowfin goby71800
AcipenseridaeNon-native sturgeon241101
Alburnus alburnusAlver, bleak14400
Alosa aestivalisblueback herring62001
Atherina boyeriBig-scale sand-smelt2400
Babka gymnotrachelusRacer goby1400
Carassius gibelioPrussian carp15*1
Channa argusNorthern snakehead37510
Coregonus albulaVendace25*0
Coregonus lavaretusEuropean whitefish11*0
Coregonus peledPeled7*0
Ctenopharyngodon idella#Grass carp212509
Cyprinella lutrensisRed shiner143252
Gambusia affinis#Western mosquitofish104003
Gambusia holbrookiEastern mosquitofish284002
Gasterosteus aculeatus#Threespine stickleback123002
Gymnocephalus cernua#Ruffe2421010
Hypomesus nipponensisWakasagi6100
Hypophthalmichthys molitrixSilver carp2217510
Hypophthalmichthys nobilisBighead carp2020010
Ictalurus furcatusBlue catfish31350
Lepomis microlophusRedear sunfish81001
Leuciscus leuciscusDace13400
Menidia beryllinaInland silverside72000
Misgurnus anguillicaudatus#Oriental weatherfish143004
Morone saxatilis x chrysopsHybrid striped bass/wiper33000
Mylopharyngodon piceusBlack carp71010
Neogobius fluviatilisBabka goby3400
Oncorhynchus ketaChum salmon3*0
Osmerus eperlanusEuropean smelt7400
Perca fluviatilisEurasian perch20403
Perccottus gleniiAmur sleeper9502
Phoxinus phoxinusCommon minnow3402
Pseudorasbora parvaStone moroko20104
Rhodeus sericeusBitterling61101
Rutilus rutilusRoach13502
Sander luciopercaZander8357
Scardinius erythropthalmus#Rudd410010
Silurus glanisWels catfish6*5
Siniperca chuatsiMandarin fish71000
Tinca tinca#Tench2354

* indicates species that have been identified by previous assessments as in one or more invasion pathway – but data on their prevalence in these pathways is scarce

# indicates species with localized Great Lakes distributions.

Invertebrate Watch List

Species nameCommon nameCombined impact score (0-72)Cumulative pathway score (0-600)No. jurisdictions regulated (0-10)Order
Fredericella sultana201100Bryozoan
PlatyhelminthesBryozoan
Ichthyocotylurus pileatus#Digenean fluke72800Bryozoan
Anodonta woodiana Chinese pond mussel8*0Mollusk
Indoplanorbis exustusRams horn snail19*0Mollusk
Limnoperna fortuneiGolden mussel3984Mollusk
Lithoglyphus naticoidesGravel snail7500Mollusk
Mytilopsis leucophaeataDark false mussel21850Mollusk
Potamopyrgus antipodarum#New Zealand mudsnail133004Mollusk
Apocorophium lacustre11500Crustacean
Calanipeda aquaedulcis1400Crustacean
Chelicorophium curvispinumCaspian mud shrimp3400Crustacean
Cherax destructorYabby (crayfish)3506Crustacean
Cherax tenuimanusHairy marron (crayfish)2102Crustacean
Cyclops kolensis1400Crustacean
Daphnia galeata galeata#waterflea73000Crustacean
Daphnia lumholtzi#waterflea23002Crustacean
Dikerogammarus haemobaphes1400Crustacean
Dikerogammarus villosusKiller shrimp7404Crustacean
Echinogammarus warpachowskyi2400Crustacean
Eriocheir sinensisChinese mitten crab163004Crustacean
Hemimysis anomala#Bloody red shrimp73002Crustacean
Limnomysis benedeni4400Crustacean
Lophopodella carteri43000Crustacean
Obesogammarus crassus6400Crustacean
Obesogammarus obesus880Crustacean
Pacifastacus leniusculusSignal crayfish17200Crustacean
Paramysis (Metamysis) ullskyi7400Crustacean
Paramysis (Serrapalpisis) lacustris3400Crustacean
Podonevadne trigona ovum280Crustacean
Pontogammarus robustoides4400Crustacean
Procambarus clarkii#Red swamp crayfish313005Crustacean
Schizopera borutzkyi#Oarsman63000Crustacean

* indicates species that have been identified by previous assessments as in one or more invasion pathway – but data on their prevalence in these pathways is scarce

# indicates species with localized Great Lakes distributions.

Plant Watch List

Species nameCommon nameCombined impact score (0-72)Cumulative pathway score (0-600)No. jurisdictions regulated (0-10)
Akebia quinataChocolate vine64001
Alnus glutinosa#black alder104001
Alternanthera philoxeroidesAlligator weed421200
Aponogeton distachyosCape pondweed23100
Artemesia absinthiumAbsinthe wormwood54001
Arundo donaxGiant reed224001
Azolla pinnataAsian mosquito fern12104
Butomus umbellatus#flowering rush64005
Cabomba caroliniana#Carolina fanwort83004
Cirsium palustre#marsh thistle82001
Colocasia esculentaCoco-yam72100
Crassula helmsiiNew Zealand pygmy weed8*3
Didymosphenia geminate^Didymo312002
Egeria densaBrazilian waterweed431756
Egeria najas51000
Eichhornia azureaAnchored water hyacinth51104
Eichhornia crassipes#Water hyacinth414503
Epilobium hirsutum#Great hairy willow herb32001
Frangula alnus#Glossy buckthorn181000
Glyceria maxima#Reed mannagrass142002
Hydrilla verticillataHydrilla492106
Hydrocharis morus-ranae#European frog-bit153006
Hydrocotyle ranunculoidesFloating marsh pennywort 195001
Hygrophila polyspermaIndian hygrophila11604
Ipomoea aquatica Swamp cabbage141104
Juncus compressus#Flattened rush32000
Juncus gerardii#Black-grass rush92100
Juncus inflexus#European meadow rush33000
Lagarosiphon major African elodea27105
Limnobium spongiaAmerican spongeplant5200
Ludwigia adscendensWater primrose6*0
Ludwigia grandiflora28101
Ludwigia hexapetalaUruguayan Primrose Willow283001
Ludwigia peploidesFloating Primrose Willow283101
Lysimachia vulgaris#Yellow loosestrife83002
Lythrum virgatumWanded loosestrife302102
Melaleuca quinquenerviaPunk tree31101
Monochoria vaginalisHeart shaped false pickerelweed8*3
Murdannia keisakWart removing herb14201
Myriophyllum aquaticumParrot feather213756
Myriophyllum heterophyllum x M. laxum26101
Najas minor#Brittle waternymph93004
Nelumbo nuciferaSacred lotus134251
Nitellopsis obtuse#^Starry stonewort263002
Nymphaea spp (except Nymphaea odorata, and N. leibergii)Non-native water lilies43001
Nymphoides peltataYellow floating heart52105
Oenanthe javanicaWater celery54001
Oxycaryum cubenseCuban bulrush8100
Pistia stratiotes#Water lettuce444002
Prymnesium parvum^Flagellated algae31502
Robinia pseudoacaciaBlack locust 123001
Rotala rotundifoliaRoundlaf toothcup31600
Sagittaria platyphyllaDelta arrowhead25200
Salix atrocinereaSmooth twig gray willow142001
Salvinia minimaWater spangles163100
Salvinia molestaKariba weed49105
Solanum tampicenseWetland nightshade4*1
Stratiotes aloidesWater soldier, water aloe53103
Trapa natans#Water chestnut262006
Typha domingensisSouthern cattail29451
Typha laxmanniiGraceful cattail71001
Typha orientalisBullrush/raupo6*0
Typha x glaucaHybrid cattail182001
Ulva species#^Green alga164001
Vallisneria spiralisEelgrass93100

* indicates species that have been identified by previous assessments as in one or more invasion pathway – but data on their prevalence in these pathways is scarce

# indicates species with localized Great Lakes distributions.

^ indicates algae

(For more information see Species Watch List Methods)

A small number of species are the subject of species-specific early detection efforts under other monitoring plans that undergo annual review and refinement. For example, the Asian Carp Regional Coordinating Committee coordinates targeted early detection and response for silver and bighead carp.