IMIS | Lifewatch regional portal

You are here

IMIS

[ report an error in this record ]basket (0): add | show Print this page

An analytically derived delineation of the West African coastal province based on bivalves
Caballero-Herrera, J.A.; Olivero, J.; Von Cosel, R.; Gofas, S. (2022). An analytically derived delineation of the West African coastal province based on bivalves. Diversity Distrib. 28(12): 2791-2805. https://dx.doi.org/10.1111/ddi.13454
In: Diversity and Distributions. Blackwell: Oxford. ISSN 1366-9516; e-ISSN 1472-4642, more
Peer reviewed article  

Available in  Authors 

Keywords
Author keywords
    Biogeographic regions, bivalves, chorotypes, Lusitanian, marine biogeography, marine regionalization, marine regions, Mauritanian, Mediterranean

Authors  Top 
  • Caballero-Herrera, J.A.
  • Olivero, J.
  • Von Cosel, R.
  • Gofas, S., more

Abstract
    Aim

    To assess the pattern of biotic regions (BR) and their boundaries, to detect chorotypes and to relate these patterns to key environmental factors.

    Location

    Eastern Atlantic Ocean.

    Time period

    Recent.

    Taxon studied

    Bivalvia.

    Methods

    Distributions were scored for 595 species. Operational geographical units are classified hierarchically using Baroni-Urbani & Buser similarity index, clusters were assessed for statistical significance with the ‘RMacoqui 1.0’ software using G tests of independence, and chorotypes were inferred likewise from similarity between species distributions.

    Results

    Three strong biotic boundaries delimit four BR: (1) European Atlantic and Mediterranean; (2) West African, from western Sahara to southern Angola; (3) Baia dos Tigres/Namibia; and (4) Saint Helena/Ascension. The West African BR is subdivided by two weak boundaries into three subordinate BR: the tropical region proper, the north-western African transition zone and the cluster (southern Angola/São Tomé/Cape Verde Islands). Of the 429 species present in West Africa, 261 (60.7%) are endemic, and 19 genera (7.2%) are endemic. Sixteen chorotypes were identified; the European BR is correlated with chorotypes C5 (149 species mostly European and Mediterranean) and C3 (38 species mostly in northern Europe), whereas the West African BR is mainly characterized by chorotype C6 (221 species). Some discontinuous distribution patterns of tropical West African species were identified as chorotypes, but subordinate to chorotype C6. The West African BR is mainly characterized by sea surface temperature and chlorophyll; characterization without the islands also involved the extensive sandy coast. The north-western African transition region is characterized by an arid climate and few rivers and influenced by seasonal upwelling. The cluster of southern Angola, Sao Tomé and Cape Verdes contrasts with the remainder of West Africa in having a predominantly rocky shore.

    Main conclusions

    The present analyses provide an objective regionalization based on species occurrences, which supports the traditional recognition of West Africa as a major biotic region with a high level of endemism. Attention is called on that the unique endemic component is insufficiently represented in current marine protected areas.


All data in the Integrated Marine Information System (IMIS) is subject to the VLIZ privacy policy Top | Authors