AquaMaps

AquaMaps combines numerical algorithms with expert knowledge1 to create standardised distribution maps for currently 7,200 species of fishes, marine mammals and invertebrates.2

Description

Reviewed native range of the Grey nurse shark Carcharias Taurus.3

AquaMaps is an approach to generating model-based, large-scale predictions of currently known natural occurrence of marine species. Models are constructed from estimates of the environmental tolerance of a given species with respect to depth, salinity, temperature, primary productivity, and its association with sea ice or coastal areas. Maps show the color-coded relative likelihood of a species to occur in a global grid of half-degree latitude / longitude cell dimensions, which corresponds to a side length of about 50 km near the equator. Predictions are generated by matching habitat usage of species, termed environmental envelopes, against local environmental conditions to determine the relative suitability of specific geographic areas for a given species. Knowledge of species’ distributions within FAO areas or bounding boxes is also used to exclude potentially suitable habitat in which the species is not known to occur.

AquaMaps was originally developed by Kristin Kaschner and colleagues to predict global distributions of marine mammals (Kaschner et al 2006)4. The approach was based on incorporating expert knowledge into an environmental envelope or ecological niche model. The use of expert knowledge compensated for the effects of species misidentifications, effort biases, and the non-representative coverage of large-scale species’ distributions. Such data gaps and problems are widespread in publicly available occurrence data sets that are compiled from different sources.

The approach developed for marine mammals was subsequently modified in collaboration with FishBase staff to make it more suitable for a greater range of marine organisms and to make use of data and information available in FishBase and OBIS/GBIF online databases. Display of the maps on the web has been facilitated by the use of C-squares Mapper developed by Tony Rees of CSIRO, Australia.5

Function

• Visualisation tools
  • Maps
• Taxonomy
  • Identification tools, keys
• User interface
  • Personal
  • Raw data and visual presentation

Why use this tool?

The AquaMaps approach was developed specifically to deal with the problems encountered when attempting to map large-scale species distributions based on existing but fragmented and potentially non-representative occurrence data. The basic and novel idea behind the AquaMaps concepts is to supplement occurrence records with independent knowledge about species distributions and habitat usage to correct for existing biases.

For instance, knowledge of the geographic extents of commercial species available from FAO can be used to define latitudinal and longitudinal bounding boxes to delimit predictions to areas known to be utilized. Area restrictions can also serve as a quality control mechanism, as they filter out outliers in occurrence records that may present misidentifications. Published depth ranges can also be used to better define associations between species distributions and depth, as these are generally based on more rigorous analyses and representative data sets, thus reducing the impacts of sampling biases.

The strength of AquaMaps compared to other species distribution modelling algorithms thus lies in its transparency and also its ability to incorporate expert knowledge and general information on species habitat usage and occurrence. 6

Who will use this tool?

• Data users
  • Expert
  • Interest groups

How will the tool be used?

• Online application
• Data can be displayed as a jpg map showing range, suitable habitat or point data
• Data can be downloaded as a .csv file
• Feedback is available as an email link
• User input required

Where in the data chain could this tool be used?

• User’s machine

When could this tool be used?

• At the time of a user request
• As a post process, after data is with the user

Availability

• AquaMaps: http://www.aquamaps.org/
• Documentation: http://fishbase.sinica.edu.tw/tools/AquaMaps/AboutAquaMaps.doc
• Cost: free
• Version 12/2007
• Licence not mentioned

Comments

• AquaMaps displays range data as well as point data
• The ALA could use AquaMaps as an example of mapping range data, using modelled data and expert knowledge. Or, it could create a link to AquaMaps on a species page.