Beta version

About MarInvaders Web App

The MarInvaders web application is an interactive tool that combines and visualizes data on marine aliens species from existing databases. It enables the user to query information per marine ecoregion, and create maps that distinguish alien and natives distributions of a species. MarInvaders aims to facilitate the development of large-scale impact assessments of marine aliens species. The MarInvaders web application is developed and maintained by the Digital Lab of the IndEcol Research Group at the Norwegian University of Science and Technology in Trondheim, Norway.

Data resources

The MarInvaders web application currently integrates data on marine (aliens) species from four existing databases: OBIS , WoRMS , GISD , and a database by NatCon et al. After the user selects an ecoregion, the OBIS API v3 is used to query all species for which there is occurrence data within that ecoregion in the OBIS database. Each species is then searched for in the latter three databases to potentially identify as alien. The WoRMS REST webservice is used to find the establishmentMeans –whether the species is flagged as alien or not-, whereas all species included in the GISD and Molnar databases as per definition alien. These databases provide geographical distributions on different scales. The Molnar distributions are on a marine ecoregion level. Most of the WoRMS distributions are either IHO Sea Areas, Exclusive Economic Zones (EEZ), or an intersect of these, and have a Marine Regions Geographic Identifier (MRGID) is easily matched to a marine ecoregion by the use of shapefiles. GISD does not provide such MRGID’s but instead gives only quantitative distributions, such as country names. Most of these could still be matched to existing shapefiles by comparing names, and subsequently be matched to marine ecoregions. All the distributions that could not automatically be matched were searched for manually and matched to one or more marine ecoregions.

How to use

To get started, click the ecoregion of interest on the map. All information on this selected ecoregion (now blue on the map) is depicted in the information tab. Information is given about in which Province and Realm the ecoregion lies, and what its corresponding MRGID is. The total Number of species within the ecoregion for which OBIS holds occurrence data, the number of species that were flagged as Alien in this ecoregion, and the number of native species in this ecoregion that have aliens species listed as a threat by the IUCN Red List. These species are listed under the tabs All species, Aliens, and Threatened. Their taxonomic name is given, as well as their AphiaID (the identifier used by WoRMS), and the source where it was reported as alien or threatened. When clicking on a species’ name, its distributions show up on the world map. The ecoregions for which there is occurrence data in OBIS are depicted in blue. Of those, the regions that were flagged as alien are depicted in red.


Alien (sightings)
Alien (total)