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Sampaio I.,University of The Azores | Braga-Henriques A.,University of The Azores | Pham C.,University of The Azores | Ocana O.,Fundacion Museo Del Mar | And 3 more authors.
Journal of the Marine Biological Association of the United Kingdom | Year: 2012

The impact of bottom trawling on cold-water corals (CWC) has been thoroughly studied and shown to be long-lasting; however the effects of bottom longlining on CWC ecosystems have received little attention. The present paper identifies the principal CWC species landed by bottom longlining in Faial (Azores) from 150 to 600 m depth. Data were obtained from a survey of 297 landings during four months coupled with 16 interviews with fishermen. A distinction was made among corals brought on deck directly entangled in the fishing gear (primary by-catch) from corals brought up associated with other larger CWC species or rocks (secondary by-catch). Forty-five (15.2%) of 297 fishing trips surveyed landed coral specimens. The survey recorded 39 different CWC taxa in the by-catch, belonging to five different orders (Scleractinia, Alcyonacea, Antipatharia, Zoanthidea and Anthoathecata). Secondary by-catch included a larger number of species but the total number of corals was in the same order of magnitude for both groups. The taxa most frequently encountered were Leiopathes spp., Errina dabneyi and Dendrophyllia sp. CWC taxa in the by-catch were mostly medium size (10-60 cm), 3-dimensional and branched colonies. Local ecological knowledge of fishermen confirmed that the corals recorded were representative of their past experience and also revealed a general agreement that there has been a decrease of CWC by-catch on traditional fishing grounds. Corals are common by-catch in bottom longline fisheries around the Azores and so conservation measures may be required. © Copyright Marine Biological Association of the United Kingdom 2012.

Braga-Henriques A.,University of The Azores | Porteiro F.M.,University of The Azores | Ribeiro P.A.,University of The Azores | De Matos V.,University of The Azores | And 3 more authors.
Biogeosciences | Year: 2013

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 900m 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. © Author(s) 2013.

Braga-Henriques A.,University of The Azores | Carreiro-Silva M.,University of The Azores | Porteiro F.M.,University of The Azores | De Matos V.,University of The Azores | And 3 more authors.
ICES Journal of Marine Science | Year: 2011

The Azores region harbours the richest communities of stylasterid corals in the Northeast Atlantic area. Of the nine deep-water species found there, Errina dabneyi seems to be the most abundant species; it is commonly collected as bycatch from longline fishing. E. dabneyi host Pedicularia gastropods on their branches, and a detailed study of shell shape and morphometry at different growth stages, complemented by shell characterization through scanning electron microscopy, allows the individuals to be identified as Pedicularia sicula. The incidence of this species on E. dabneyi was high (69.8%), with abundances ranging between 1 and 223 individuals per colony. The pediculariids exhibited a high degree of plasticity and produced evident traces on the stylasterid skeletons at their fixation points, suggesting that they are ectoparasites and not predators of E. dabneyi. The stylasterid colonies also hosted a rich associated fauna dominated by suspension-feeders using the coral as substratum and for protection. © 2010 International Council for the Exploration of the Sea. Published by Oxford Journals. All rights reserved.

Carreiro-Silva M.,University of The Azores | Braga-Henriques A.,University of The Azores | Sampaio I.,University of The Azores | De Matos V.,University of The Azores | And 2 more authors.
ICES Journal of Marine Science | Year: 2011

In the Azores, Northeast Atlantic, an undescribed epizoan zoanthid is often found in association with the cold-water gorgonian Callogorgia verticillata at 110-800 m depth. This zoanthid was identified as a new species, Isozoanthus primnoidus sp. nov., based on morphological and anatomical characters of the polyps and type of cnidae. The distinguishing features of I. primnoidus are coenenchyme, column, and oral disc light brown, with short, translucent tentacles. Contracted polyps have column diameter up to 3 mm and height up to 2 mm. Ectoderm and outer mesogloea are densely encrusted with mineral particles and gorgonian sclerites. Capitulum bears a maximum of 14 distinctive ridges. Isozoanthus primnoidus was associated with 17% of C. verticillata colonies studied, and covered 14±5% of the gorgonian colony. There was strong evidence of a parasitic relationship whereby I. primoidus progressively eliminates gorgonian tissue and uses the gorgonian axis for structure and support, and sclerites for protection. © 2010 International Council for the Exploration of the Sea. Published by Oxford Journals. All rights reserved.

Sinniger F.,Japan Agency for Marine - Earth Science and Technology | Sinniger F.,University of Ryukyus | Ocana O.V.,Fundacion Museo del Mar | Baco A.R.,Florida State University
PLoS ONE | Year: 2013

The Hawaiian gold coral has a history of exploitation from the deep slopes and seamounts of the Hawaiian Islands as one of the precious corals commercialised in the jewellery industry. Due to its peculiar characteristic of building a scleroproteic skeleton, this zoanthid has been referred as Gerardia sp. (a junior synonym of Savalia Nardo, 1844) but never formally described or examined by taxonomists despite its commercial interest. While collection of Hawaiian gold coral is now regulated, globally seamounts habitats are increasingly threatened by a variety of anthropogenic impacts. However, impact assessment studies and conservation measures cannot be taken without consistent knowledge of the biodiversity of such environments. Recently, multiple samples of octocoral-associated zoanthids were collected from the deep slopes of the islands and seamounts of the Hawaiian Archipelago. The molecular and morphological examination of these zoanthids revealed the presence of at least five different species including the gold coral. Among these only the gold coral appeared to create its own skeleton, two other species are simply using the octocoral as substrate, and the situation is not clear for the final two species. Phylogenetically, all these species appear related to zoanthids of the genus Savalia as well as to the octocoral-associated zoanthid Corallizoanthus tsukaharai, suggesting a common ancestor to all octocoral-associated zoanthids. The diversity of zoanthids described or observed during this study is comparable to levels of diversity found in shallow water tropical coral reefs. Such unexpected species diversity is symptomatic of the lack of biological exploration and taxonomic studies of the diversity of seamount hexacorals. © 2013 Sinniger et al.

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