Publication Date:
2015-09-21
Description:
Ecological and taxonomic study of the mollusk-rich fauna of the Golfe
d’Arguin, North Mauritania, investigates the various environmental
influences affecting this tropical shelf. The upwelling of nutrient-rich
waters leads to a highly productive environment under tropical conditions.
The resulting mixed carbonate-siliciclastic sediment contains a large
portion of calcareous components produced by heterotrophic organisms—
e.g., mollusks, foraminifers, worms, barnacles—that are reworked on the
open shelf. On the basis of mollusk assemblages, six taphocoenoses are
defined, all being characterized by a mixed fauna of tropical (e.g., Tellina
densestriata), subtropical (e.g., Macoma cumana) and temperate (e.g.,
Spisula subtruncata) species. Differences between the assemblages are
related to the medium—grain size ranging from mud to gravel—that
results from local hydrodynamic conditions and water depth. Among
carbonate grains, Donax burnupi shells are very abundant in the swellexposed,
northern part of the Golfe d’Arguin and reflect the tropical to
subtropical, high-energy, and high-nutrient waters. Mollusk assemblages
are demonstrated to be a sensitive tool for deciphering complex
environmental conditions in sedimentary archives.
Type:
Article
,
PeerReviewed
Format:
text
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