NAS Graphs and Charts: All Introduced Aquatic Species in the US



**Click on a graph to see the data**

The graph shows the cumulative number of species that have been introduced up until the last year listed.
up to present: 1323 species up to 2000: 1122 species up to 1950: 435 species up to 1900: 181 species up to present: 1323 species up to 2000: 1122 species up to 1950: 435 species up to 1900: 181 species Introduced Species in United States
This graph shows the percentage of species that are native transplants (native to a portion of the US but moved to a non-native area in the US) and exotic transplants (not native to the US).
Exotic to US: 674 species Exotic to US: 674 species Native Transplants: 589 species Native Transplants: 589 species Hybrid: 49 species Hybrid: 49 species Cryptogenic: 9 species Cryptogenic: 9 species Unknown: 4 species Unknown: 4 species Introduced Species in United States
This graph shows the proportion of species that have been introduced into the United States that belong to various taxonomic groups.
Fishes: 598 species Fishes: 598 species Plants: 243 species Plants: 243 species Marine Fishes: 139 species Marine Fishes: 139 species Amphibians-Frogs: 50 species Amphibians-Frogs: 50 species Reptiles-Turtles: 49 species Reptiles-Turtles: 49 species Mollusks-Gastropods: 42 species Mollusks-Gastropods: 42 species Crustaceans-Copepods: 31 species Crustaceans-Copepods: 31 species Crustaceans-Crayfish: 29 species Crustaceans-Crayfish: 29 species Mollusks-Bivalves: 28 species Mollusks-Bivalves: 28 species Amphibians-Salamanders: 17 species Amphibians-Salamanders: 17 species Crustaceans-Shrimp: 15 species Crustaceans-Shrimp: 15 species Reptiles-Snakes: 13 species Reptiles-Snakes: 13 species Crustaceans-Cladocerans: 9 species Crustaceans-Cladocerans: 9 species Crustaceans-Crabs: 9 species Crustaceans-Crabs: 9 species Crustaceans-Amphipods: 8 species Crustaceans-Amphipods: 8 species Reptiles-Crocodilians: 8 species Reptiles-Crocodilians: 8 species Mammals: 6 species Mammals: 6 species Crustaceans-Isopods: 4 species Crustaceans-Isopods: 4 species Bryozoans: 4 species Bryozoans: 4 species Coelenterates-Hydrozoans: 3 species Coelenterates-Hydrozoans: 3 species Algae: 3 species Algae: 3 species Crustaceans-Mysids: 3 species Crustaceans-Mysids: 3 species Mollusks-Cephalopods: 2 species Mollusks-Cephalopods: 2 species Rotifers: 2 species Rotifers: 2 species Reptiles-Lizards: 1 species Reptiles-Lizards: 1 species Platyhelminthes: 1 species Platyhelminthes: 1 species Entoprocts: 1 species Entoprocts: 1 species Crustaceans-Barnacles: 1 species Crustaceans-Barnacles: 1 species Amphibians-Caecilians: 1 species Amphibians-Caecilians: 1 species Coelenterates-Scyphozoan: 1 species Coelenterates-Scyphozoan: 1 species Annelids-Hirundinea: 1 species Annelids-Hirundinea: 1 species Annelids-Oligochaetes: 1 species Annelids-Oligochaetes: 1 species Groups Introduced into United States
Each category represents a combination of a species introduced via a pathway. A single species can be introduced by more than one pathway and may therefore be counted more than once.
unknown: 417 species unknown: 417 species stocked: 340 species stocked: 340 species aquarium release: 320 species aquarium release: 320 species hitch hiker: 252 species hitch hiker: 252 species dispersed: 218 species dispersed: 218 species bait release: 215 species bait release: 215 species canal: 123 species canal: 123 species shipping: 117 species shipping: 117 species aquaculture: 115 species aquaculture: 115 species pet release: 101 species pet release: 101 species released: 83 species released: 83 species planted: 79 species planted: 79 species escaped captivity: 78 species escaped captivity: 78 species hybridized: 20 species hybridized: 20 species released lab animals: 8 species released lab animals: 8 species other: 7 species other: 7 species Introduction Pathways
This graph shows the cumulative number of species introduced in 50-year increments. The bars are further divided to show those that are native transplants (native to a portion of the US but moved to a non-native area in the US) and exotic transplants (not native to the US).
up to present & Unknown: 4 species up to present & Cryptogenic: 9 species up to present & Hybrid: 49 species up to present & Exotic to US: 674 species up to present & Native Transplants: 589 species up to 2000 & Unknown: 4 species up to 2000 & Cryptogenic: 5 species up to 2000 & Hybrid: 39 species up to 2000 & Exotic to US: 537 species up to 2000 & Native Transplants: 538 species up to 1950 & Unknown: 0 species up to 1950 & Cryptogenic: 1 species up to 1950 & Hybrid: 3 species up to 1950 & Exotic to US: 173 species up to 1950 & Native Transplants: 259 species up to 1900 & Unknown: 0 species up to 1900 & Cryptogenic: 1 species up to 1900 & Hybrid: 1 species up to 1900 & Exotic to US: 79 species up to 1900 & Native Transplants: 100 species Native/Exotic Introductions over time
This analysis includes all species introduced into either freshwater or marine areas, including those that did not become established. Estuarine species are included as marine.
Freshwater: 1219 species Freshwater: 1219 species Marine: 170 species Marine: 170 species Brackish: 108 species Brackish: 108 species Marine Vs Freshwater Of Introduce times in United States
This graph is based on all taxa introduced into the region or states at any time. They include species that did not become established.
up to present & Marine: 108 species up to present & Brackish: 170 species up to present & Freshwater: 1219 species up to 2000 & Marine: 55 species up to 2000 & Brackish: 110 species up to 2000 & Freshwater: 1051 species up to 1950 & Marine: 10 species up to 1950 & Brackish: 22 species up to 1950 & Freshwater: 399 species up to 1900 & Marine: 3 species up to 1900 & Brackish: 5 species up to 1900 & Freshwater: 172 species Freshwater/Marine Introductions over time
This graph represents all species and all pathways and includes species that did not become established.
North America: 597 species North America: 597 species Asia: 179 species Asia: 179 species South America: 146 species South America: 146 species Eurasia: 83 species Eurasia: 83 species Indo-Pacific: 77 species Indo-Pacific: 77 species Africa: 61 species Africa: 61 species Europe: 32 species Europe: 32 species North and Central America: 32 species North and Central America: 32 species South and Central America: 29 species South and Central America: 29 species Central America: 21 species Central America: 21 species Australia: 19 species Australia: 19 species Unknown: 18 species Unknown: 18 species Caribbean: 10 species Caribbean: 10 species Europe and Africa: 10 species Europe and Africa: 10 species Pacific Ocean: 4 species Pacific Ocean: 4 species Northwest Pacific: 3 species Northwest Pacific: 3 species Southwest Pacific: 2 species Southwest Pacific: 2 species AustralAsia: 2 species AustralAsia: 2 species Asia and Africa: 1 species Asia and Africa: 1 species North and South America: 1 species North and South America: 1 species Origin of Introduced Species in United States

Disclaimer:

The data represented on this site vary in accuracy, scale, completeness, extent of coverage and origin. It is the user's responsibility to use these data consistent with their intended purpose and within stated limitations. We highly recommend reviewing metadata files prior to interpreting these data.

Citation information: U.S. Geological Survey. [2025]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [5/2/2025].

Contact us if you are using data from this site for a publication to make sure the data are being used appropriately and for potential co-authorship if warranted.

For general information and questions about the database, contact Wesley Daniel. For problems and technical issues, contact Matthew Neilson.