Description: Swiftia phaeton, a new species, is described for Mauritania where it is endemic at the upper bathyal. This azooxanthellate octocoral is distinctive from congeneric species in the NE Atlantic and Mediterranean Sea by the dark red coloration of the colonies and polyps, the presence of a layer of rod sclerites on top of the calyces and different sizes of polyps and sclerites. Coral gardens dominated by a species of the genus Swiftia Duchassaing & Michelotti, 1864 were filmed for the first time it the southern NE Atlantic Ocean. The extensive Swiftia phaeton sp. nov. dominated habitats were recorded during the Phaeton expedition onboard Maria S. Merian in 2010 at the Mauritanian Slope between 20°24N and 17°54N in 470 - 640 m depth, co-occurring with the framework-forming scleractinians Lophelia pertusa (Linnaeus, 1758) and Madrepora oculata (Linnaeus, 1758). ROV video annotation based on size and density distribution of Swiftia enabled the characterization of the new biotope.

Description: Stable oxygen and carbon isotopes were measured on (i) the planktic foraminifera species Globigerinoides ruber (white) and alternatively, in samples in which G. ruber was lacking, on Globigerinoides conglobatus; and (ii) the benthic foraminifera species Cibicidoides pachyderma and alternatively, in samples in which C. pachyderma was lacking, on Cibicides lobatulus. 10–15 planktic and 4-6 benthic specimens of the fraction 〉250 μm were selected. Additionally, attention was paid to select specimens of similar size to minimise influences of metabolic effects and changing preferential habitats during ontogeny. For cleaning and removal of sediment, the selected foraminifera were cracked between two glass plates, transferred to a sample cup, covered with ethanol and immerged into an ultrasonic bath for 5–10 s. The sediment brought into suspension was decanted. The procedure was repeated until the ethanol remained clear after the ultrasonic bath. The cleaned foraminifera were reacted with 100% phosphoric acidat 75 °C using a Kiel III online carbonate preparation line connected to a ThermoFinnigan 252 mass spectrometer (Geochemical Laboratory of the GeoZentrum Nordbayern,Germany). Isotopic data are expressed in per mil relative to V-PDB by assigning a δ18O-value of -2.20 ‰ to NBS19, using the standard δ-notation. The reproducibility was checked by replicate analysis of laboratory standards and was found to be better than ±0.05 for δ18O and δ13C (1σ).

Description: This study presents aggradation rates supplemented for the first time by carbonate accumulation rates from Mediterranean cold-water coral sites considering three different regional and geomorphological settings: (i) a cold-water coral ridge (eastern Melilla coral province, Alboran Sea), (ii) a cold-water coral rubble talus deposit at the base of a submarine cliff (Urania Bank, Strait of Sicily) and (iii) a cold-water coral deposit rooted on a predefined topographic high overgrown by cold-water corals (Santa Maria di Leuca coral province, Ionian Sea). The mean aggradation rates of the respective cold-water coral deposits vary between 10 and 530 cm kyr-1 and the mean carbonate accumulation rates range between 8 and 396 g cm-2 kyr-1 with a maximum of 503 g cm-2 kyr-1 reached in the eastern Melilla coral province. Compared to other deep-water depositional environments the Mediterranean cold-water coral sites reveal significantly higher carbonate accumulation rates that were even in the range of the highest productive shallow-water Mediterranean carbonate factories (e.g. Cladocora caespitosa coral reefs). Focusing exclusively on cold-water coral occurrences, the carbonate accumulation rates of the Mediterranean cold-water coral sites are in the lower range of those obtained for the prolific Norwegian coral occurrences, but exhibit much higher rates than the cold-water coral mounds off Ireland. This study clearly indicates that cold-water corals have the potential to act as important carbonate factories and regional carbonate sinks within the Mediterranean Sea. Moreover, the data highlight the potential of cold-water corals to store carbonate with rates in the range of tropical shallow-water reefs. In order to evaluate the contribution of the cold-water coral carbonate factory to the regional or global carbonate/carbon cycle, an improved understanding of the temporal and spatial variability in aggradation and carbonate accumulation rates and areal estimates of the respective regions is needed.

Description: Cold-water coral ecosystems present common carbonate factories along the Atlantic continental margins, where they can form large reef structures. There is increasing knowledge on their ecology, molecular genetics, environmental controls and threats available. However, information on their carbo-nate production and accumulation is still very limited, even though this information is essential for their evaluation as carbonate sinks. The aim of this study is to provide high-resolution reef aggradation and carbonate accumulation rates for Norwegian cold-water coral reefs from various settings (sunds, inner shelf and shelf margin). Furthermore, it introduces a new approach for the evaluation of the cold-water coral preservation within cold-water coral deposits by computed tomography analysis. This approach allows the differentiation of various kinds of cold-water coral deposits by their macrofossil clast size and orientation signature. The obtained results suggest that preservation of cold-water coral frameworks in living position is favoured by high reef aggradation rates, while preservation of coral rubble prevails by moderate aggradation rates. A high degree of macrofossil fragmentation indicates condensed intervals or unconformities. The observed aggradation rates with up to 1500 cm kyr**-1 exhibit the highest rates from cold-water coral reefs so far. Reef aggradation within the studied cores was restricted to the Early and Late Holocene. Available datings of Norwegian cold-water corals support this age pattern for other fjords while, on the shelf, cold-water coral ages are reported additionally from the early Middle Holocene. The obtained mean carbonate accumulation rates of up to 103 g cm**-2 kyr**-1 exceed previous estimates of cold-water coral reefs by a factor of two to three and by almost one order of magnitude to adjacent sedimentary environments (shelf, slope and deep sea). Only fjord basins locally exhibit carbonate accumulation rates in the range of the cold-water coral reefs. Furthermore, cold-water coral reef carbonate accumulation rates are in the range of tropical reef carbonate accumulation rates. These results clearly suggest the importance of cold-water coral reefs as local, maybe regional to global, carbonate sinks.

Description: This paper presents the first compilation of information on the spatial distribution of scleractinian cold-water corals in the Gulf of Cádiz based on literature research and own observations (video footage, sediment samples). Scleractinian cold-water corals are widely distributed along the Spanish and Moroccan margins in the Gulf of Cádiz, where they are mainly associated with mud volcanoes, diapiric ridges, steep fault escarpments, and coral mounds. Dendrophyllia cornigera, Dendrophyllia alternata, Eguchipsammia cornucopia, Madrepora oculata and Lophelia pertusa are the most abundant reef-forming species. Today, they are almost solely present as isolated patches of fossil coral and coral rubble. The absence of living scleractinian corals is likely related to a reduced food supply caused by low productivity and diminished tidal effects. In contrast, during the past 48 kyr scleractinian corals were abundant in the Gulf of Cádiz, although their occurrence demonstrates no relationship with main climatic or oceanographic changes. Nevertheless, there exists a conspicuous relationship when the main species are considered separately. Dendrophylliids are associated with periods of relatively stable and warm conditions. The occurrence of L. pertusa mainly clusters within the last glacial when bottom current strength in the Gulf of Cádiz was enhanced and long-term stable conditions existed in terms of temperature. Madrepora oculata shows a higher tolerance to abrupt environmental changes.