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Ocean Biogeographic Information System USA


The OBIS-USA biogeographic tool provides a summary of the biodiversity (either as lists of species or as certain common diversity indices (see below)) for defined biogeographic or jurisdictional regions. Currently, the three regions are supported:

The following statistics were calculated per region.

To visualize a layer of one of the regions, turn on the layer in the Defined Geographic Regions contained in the legend.
A simple click on any region depicted on the map, you can view summary information on the region that is contained in the OBIS-USA database.
To view the diversity calculation for all the regions, click the layer name under the Diversity Indices panel on the legend. This will display the various indices in tabular graphical formats.

Biodiversity indices

Three biodiversisity indices were calculated per region using the formulas in Table 1.
Only observations whose taxa were identified at the taxonomic rank of species or subspecies were included.

Table 1: Formulas for the species diversity indices presented in The OBIS-USA biogeographic tool where S is the number of species, N is the total number of individual animals, Ni is the number of individuals of the ith species, and pi is the proportion of the ith species (Ni/N). In the Hurlbert's index, n is a common sample size, which was arbitrarily picked as 50 in the calculations.

These indices and statistics were calculated to provide the user with some initial/preliminary insight and relative comparison of localities and datasets using the latest OBIS-USA data holdings. These Data were collected with different goals, survey designs, platforms and methods and may not be directly comparable. No adjustments (for sampling, taxonomic, spatial and/or temporal biases) were made in order to develop these indices.

To learn more about biodiversity indices, below are some useful references.


Links to journal papers may need a subscription to the journal to get the PDF version.