AquaMaps: An Overview

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AquaMaps An Overview
Kathleen Kesner-Reyes, Eli E. Agbayani, Rainer
Froese, Jonathan Ready, Ma. Josephine France R.
Barile and Kristin Kaschner
FishBase Project-The WorldFish Center,
Leibniz-Institut für Meereswissenschaften
-GEOMAR, Swedish Museum of Natural History, Sea
Around Us Project-University of British Columbia
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What are AquaMaps?

• Model-based, large-scale predictions of known
  natural occurrence of marine species
• Originally developed by Kaschner et al. (2006) to
  predict global distributions of marine mammals
• Uses estimates of environmental tolerances of a
  given species with respect to a set environmental
  parameters
• Predictions made by matching species tolerances
  (environmental envelope) against local
  environmental conditions to determine suitability
  of a geographical area for a given species
• Color-coded species range map showing relative
  likelihood of species occurrence in a global grid
  of half-degree latitude and longitude dimensions
• Supplements existing occurrence data with
  independent knowledge about species distribution
  and habitat usage to correct for biases in
  species occurrence records.

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Environmental envelope type modeling approach
Species-specific environmental envelope
Predictor
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How does AquaMaps work?
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Getting Minimum Information
Grey triggerfish Balistes capriscus Gmelin, 1789

• Depth range
• Pelagic?
• FAO areas
• Bounding box coordinates
• occurrence points (minimum of 10)
• OBIS Ocean Biogeographic Information System
  (www.iobis,org)
• GBIF Global Biodiversity Information Facility
  (www.gbif.org)

Species and online point databases are primary
sources of key minimum input data.
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Selecting Good Cells

• good cells - within bounding box or known FAO
  areas
• minimum of 10 good cells for needed for
  extracting parameters

Bounding box or FAO area limits serve as
independent verification of the validity of
occurrence records.
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Extracting Environmental Parameters
Global grid of 259,200 half degree cells
Good cells are used to derive the range of
environmental parameters within the species
native range.
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Building Environmental Envelopes

• Depth ranges typically from literature depth
  estimate based on habitat description
• Min 25th percentile - 1.5 interquartile or
  absolute minimum in extracted data (whichever is
  lesser)
• Max 75th percentile 1.5 interquartile or
  absolute maximum in extracted data (whichever is
  greater)
• PrefMin 10th percentile of observed
  variation in an environmental parameter
• PrefMax 90th percentile of observed
  variation in an environmental parameter
• Surface values for species with min depth
  200m
• Bottom values for species with min depth gt 200m

The environmental envelopes describe tolerances
of a species with respect to each environmental
parameter.
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Predicting Probability of Occurrence
PMax
Relative probability of occurrence
Predictor
Preferred max
Min
Max
Preferred min
Probabilities of species occurrence are generated
by matching the species environmental envelope
against local environmental conditions to
determine relative suitability of a given area.
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Plotting Species AquaMaps
Predictions document large-scale and long-term
presence of a species. They cannot be assumed to
precisely represent local occurrence of a species
on a specific day of a specific year.
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Balistes capriscus
All suitable habitat
Point data
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Collaborators
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• www.aquamaps.org

Kaschner, K., J. S. Ready, E. Agbayani, J. Rius,
K. Kesner-Reyes, P. D. Eastwood, A. B. South, S.
O. Kullander, T. Rees, C. H. Close, R. Watson, D.
Pauly, and R. Froese.  2008 AquaMaps Predicted
range maps for aquatic species. World wide web
electronic publication, www.aquamaps.org, Version
MM/YYYY.