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Titel |
Diversity, distribution and spatial structure of the cold-water coral fauna of the Azores (NE Atlantic) |
VerfasserIn |
A. Braga-Henriques, F. M. Porteiro, P. A. Ribeiro, V. Matos, Íacute Sampaio, O. Ocaña, R. S. Santos |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 10, no. 6 ; Nr. 10, no. 6 (2013-06-19), S.4009-4036 |
Datensatznummer |
250018298
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Publikation (Nr.) |
copernicus.org/bg-10-4009-2013.pdf |
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Zusammenfassung |
Cold-water corals are widely considered as important structural components
of benthic habitats, potentially enhancing local abundance in a variety of
fish and invertebrate species. Yet, current knowledge of the taxonomic
diversity and distribution patterns of these vulnerable, slow-growing
organisms is scarce and fragmented, limiting the effectiveness of spatial
management and conservation measures. We have conducted an exhaustive
compilation of records of alcyonaceans, antipatharians, scleractinians and
stylasterids available through present day to assess the diversity,
distribution and spatial structure of coral assemblages in the Azores
exclusive economic zone (EEZ). The resulting database comprises 2501 entries
concerning historical oceanographic expeditions and other published sources,
as well as unpublished data from bottom longline by-catch. Our taxonomic
inventory appears to be fairly complete for the explored habitats,
accounting for 164 species (79 alcyonaceans, 58 scleractinians, 18
antipatharians and 9 stylasterids), nine of which were documented for the first time. The Azores EEZ harbours a mixed coral fauna with several
zoogeographic origins, showing the closest affinity with the
Lusitanian–Mediterranean region. Very few apparent endemics were found (14%), and only in part supported by consistent sampling. Coral diversity is
particularly high between 300 and 900 m depths, in areas recognized as
traditional fishing grounds or exploitable fish habitat within the 100-mile
limit of the EEZ. The composition of coral assemblages shows significant
geographical structure among longitudinal sections of the study area at
comparable depths (100–1500 m). There is no evidence of a possible role of
the Mid-Atlantic Ridge or latitudinal effects underlying this pattern, which
suggests that it may instead reflect assemblage variability among features.
Stronger changes in species composition were found along the bathymetric
gradient. Notwithstanding the mix of partially overlapping steno- and
eurybathic species that characterize the vertical distribution of corals,
there is a distinct transition from shallow (100–600 m) to intermediate
(600–1000 m) depths. The analysis presented here constitutes a valuable
contribution for efficient conservation policies of coral-associated
vulnerable marine ecosystems and their sustainable use as fishing areas. |
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