Table of Contents
- Overview
- About the data
- How to search the data
- Species status definitions
- Data collection methods
- Cite NEMESIS
- I found a mistake in a record
- References
Overview
The Marine Invasions Research Laboratory at the Smithsonian Environmental Research Center (SERC) developed the NEMESIS database for researchers, resource managers, and stakeholders as a resource to provide comprehensive information on introduced marine and estuarine species of invertebrates and algae with established populations in the continental United States and beyond.
Introductions occur when species are moved beyond their historical or native geographic range by human activities. Marine and estuarine species have been moved around the world since the time of the Vikings. Globalization increased the number of species introductions from a low number during early colonization to a major increase during industrialization, when the movement of species for trade and aquaculture peaked. Augmented awareness and regulations are working to find solution and reduce the problem, but new marine species are still arriving as unintentional introductions associated with trade, including shipping-related pathways such as ballast water and hull fouling. The impacts of many introduced species have gone unnoticed and unreported, while others have fundamentally changed the structure and function of ecosystems and impacted many dimensions of human society.
About the data
The NEMESIS database includes species records for about 500 marine and estuarine species of invertebrates, algae, and fishes introduced into the United States in North America, which includes the lower 48 states plus Alaska (Hawaii is not yet fully included in NEMESIS, although information on some non-native species are available for that state).
Species records include:
- Photographic images and descriptions
- History of introduction and spread
- Mechanisms (vectors) of introduction; how species may move from one place to another
- Information on the biology, ecology, and effects of introduction (impacts)
- Global distribution maps of native and introduced range(s)
- References to available literature for species and invasion information
How to search the data
Species can be searched directly in the search bar located in the upper right-hand corner with genus and/or species name, or by common name if known. Use wildcard characters around the search input (%) if only part of the name is known. For example %poly% will return all species with "poly" in the name, plus the taxonomic group "polychaetes".
Species can also be searched by taxonomic group and by geographic region.
Taxonomic group profiles include:
- Cumulative summary graphics on the number of species introduced over time
- The geographic regions where they have been introduced
- A downloadable species list included in that taxonomic group
The regions page includes an interactive map of geographic bioregions as well as bays within a bioregion. Bioregions are based off the International Union for Conservation of Nature (IUCN) categorization system. Bays are based off of NOAA's Complete Coastal Assessment Framework. Selecting a bioregion or bay will result in a summary page for the region which includes:
- A cumulative graph of species introduced into the geographic region over time
- A bar graph of the number of species introduced by taxonomic group
- A downloadable list of all species introduced into that bioregion or bay, alphabetical by taxonomic group, with the year of first introduction in that area.
In addition, a downloadable list of taxonomic species in the NEMESIS portal is maintained and updated.
Species status definitions
NEMESIS defines the species status using these categories:
Invasion Status
Invasion status refers to the geographical limit range of a species; whether a species is considered native, non-native, or its native origin is uncertain or unknown (cryptogenic) in a particular geographic area. It does not relate to how many organisms are present in a given area.
Native A species that is considered native, endemic or indigenous to a particular region.
Non-native A species that is not native or is non-indigenous to a particular region; it is found outside its native or historical range.
Cryptogenic A species whose historical geographic origin is uncertain/unknown and therefore its status is unclear for a given region.
Population Status
Population status refers to the presence or absence of a non-native organism in a certain number of specimens, or the maintenance of some form of population within its non-native region.
Eradicated A non-native population that was eliminated by human intervention.
Established A non-native species determined to have a sustained population within its introduced region. This includes multiple observations of an organism and/or evidence of its reproduction (aka presence of larvae or juveniles, eggs or gametes), and/or evidence of its survival over time. Maintaining populations can also include human mediated stocking of organisms, such as for fisheries.
Extinct A previously established population that died off on its own and now is not found within the geographic bounds of a region.
Failed A species whose presence was either a known introduction into a new region, or had been observed at some point in time, but was unable to sustain its presence through survival or reproduction, and therefore was never established.
Stocked A species whose population is maintained by sanctioned introduction by a natural resource agency.
Unknown A species whose status for a given region is not known at present, usually due to lack of information such as no recorded information within the past 20--30 years, or for more recent introductions, too few records to determine its status. A species may have been collected or observed but it is unclear whether that species is established yet.
Depending on the circumstances, a species may be native or cryptogenic in one part of the United States but considered a non-native introduction in another part. For example, Rhithropenopeus harrisii or the white fingered mud crab is native to the Northwestern Atlantic but has been introduced into the Pacific United States, including California and Oregon.
Data collection methods
The data compiled in NEMESIS comes from a combination of published literature, scientific surveys of marine and estuarine communities conducted by the Marine Invasions Research Laboratory, and input from experts in the field. Most of the literature review was compiled by the late Dr. Paul Fofonoff and is ongoing by the NEMESIS team. Species records are reviewed and edited by taxonomic experts and scientists in the field and made available online. Records are updated as new information becomes available.
Cite NEMESIS
Fofonoff PW, Ruiz GM, Steves B, Simkanin C, & Carlton JT. 2018. National Exotic Marine and Estuarine Species Information System. https://invasions.si.edu/nemesis. Access Date: October 22, 2024
I found a mistake in a record
Please contact nemesis@si.edu for any questions or comments pertaining to a species record.
References
Kelleher, G., Bleakley, C., & Wells, S. M. (1995). A Global Representative System of Marine Protected Areas (Vols. 1--4). IUCN; Great Barrier Reef Marine Park Authority; World Bank. Washington, DC
Northwest Fisheries Science Center, 2024: Coastal Assessment Framework - National Assessment of Estuary and Coastal Habitats from 2010-06-15 to 2010-08-15. NOAA National Centers for Environmental Information, https://www.fisheries.noaa.gov/inport/item/30858.
Ruiz, Gregory M, Paul W Fofonoff, Brian P Steves, and James T Carlton. 2015. "Invasion History and Vector Dynamics in Coastal Marine Ecosystems: A North American Perspective." Aquatic Ecosystem Health & Management 18 (3): 299--311.