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As awareness of deep-sea corals increases, global efforts to conserve them are increasing as well. Oceana, a non-governmental conservation organization that merged with the American Oceans Campaign in 2002, is focusing significant attention and resources on the conservation of deep-sea coral communities in United States’ waters. Oceana is carrying out a number of activities as part of its deep-sea coral campaign. These include: • Working to pass legislation that would ban the use of particularly destructive bottom trawls in all U.S. waters in collaboration with the Marine Conservation Biology Institute;• Working to pass legislation that would specifically protect known deep-sea coral and sponge areas and establish a process for future protections;• Working to protect deep-sea coral and sponge habitats in the U.S. through the regional fishery management councils;• Developing educational materials for decision-makers, the media, and the general public;• Developing a petition to achieve threatened or endangered species status for Oculina varicosa. The goal of Oceana’s deep-sea coral protection activities is to ban bottom trawling in all U.S. waters containing significant amounts of deep-sea corals and sponges by the end of 2006. The purpose of this paper is to discuss the activities that Oceana is engaged in to achieve this goal. As Oceana’s capacity develops in other parts of the world, its efforts to protect coral in other regions (especially Europe and South America) will increase as well. [ABSTRACT FROM AUTHOR]

This paper presents an overview of the spatial distribution and morphology of coral banks in the Porcupine Seabight in relation to their environmental settings. The study area is characterised by well-delimited clusters of coral banks, each featuring typical bank morphology and environmental setting. In the central part of the basin, two mound provinces can be identified: a set of complex fl at topped seafloor mounds in the Hovland Mound province is flanked to the north by a crescent of numerous north-south elongated buried coral banks in the Magellan Mound province, along the eastern margin of the basin partly buried and seabed coral banks represent the Belgica Mound province. The banks are mound-shaped elevations, many of them hosting living deep-water corals (Lophelia pertusa, Madrepora oculata, Desmophyllum cristagalli, Dendrophyllia sp.) and associated fauna. This active biological layer covers a dead assemblage of corals clogged with mud. All coral banks, buried or seabed, occur in association with current-induced features (e.g., scouring features, dunes) and steep palaeo- and present-seabed slopes. Only a few banks have a present-day seabed expression, which suggests that environmental conditions have been more favourable for bank development in the past. The depth range of the seabed coral banks coincides with the Mediterranean Outflow Water which may control indirectly the coral distribution. The distribution of corals in the southern part of the North Atlantic and the actual link with Mediterranean water suggest a possible migration of corals within the Mediterranean water along the NE Atlantic margin. The start-up phase of the coral bank development in the basin has taken place simultaneously for all provinces, and tentatively framed in times subsequent to a Late Pliocene period of erosion and non-deposition. It is considered that the sedimentary load of the currents plays an important role in the bank development. Coral banks accrete by the active baffling of sediment by the biological framework and growth of the biological cap. When sedimentation and biological growth get out of balance, the framework will progressively be clogged with sediment. Once sediment dominates the structure the coral banks get buried and draped by sediment. [ABSTRACT FROM AUTHOR]

This paper describes the associated fauna of the deep-sea gorgonian corals Paragorgia arborea and Primnoa resedaeformis. Composition and distribution of this fauna is described based on material from the continental shelf and slope off Atlantic Canada (300–600 m depth). Samples were collected from five areas with Remotely Operated Vehicle, video grab, and bottom trawl. The collected material consists of 25 samples, 13 from P. arborea and 12 from P. resedaeformis. A total of 114 species and 3915 individuals were recorded. The P. resedaeformis fauna was more abundant and diverse than the fauna of P. arborea, with 2651 specimens and 97 species found on the former and 1264 specimens and 47 species on the latter. Rarefaction analysis indicated that many more associated species are still to be found. Species richness and abundance was significantly correlated with coral morphology (e.g., number of branches, wet weight, and % exposed skeleton). Crustaceans dominated the fauna, contributing 46 % to the total number of individuals and 26 % to the total number of species. Two coral microhabitats were identified: 1) young and live parts of colonies and, 2) old parts with deposits and exposed skeleton. Most of the associated fauna was found in the latter habitat. There was a clear difference in fauna composition of the two coral species. Sessile hydroids, anemones, and molluscs were more abundant on P. resedaeformis. These organisms occurred attached to the hard substratum provided by the exposed skeleton. Parasitic copepods and polychaetes were more common on P. arborea. Two copepods, a lichomolgid ecto-parasite and a lamippid gall-forming endoparasite, were associated with P. arborea. The echinoderm Gorgonocephaluslamarckii was found in the high current environment on the outer branches of P. arborea. The shrimp Pandalus propinquus was hiding and resting on colonies of both coral species. Many of the associated taxa are also found on tropical gorgonians but the deepsea gorgonians lack the diverse decapod and gastropod-fauna of their tropical counterparts. The species richness of the deep-sea gorgonian coral fauna was higher than what has been observed for tropical gorgonians. In contrast to the tropical associates very few are obligate symbionts. Nevertheless, several of the species are rare in other habitats and have been recorded on the same and other gorgonian species in early studies from the eastern North Atlantic. The sampling gear collected the fauna differently. Corals from bottom trawls had a poorer associated fauna that differed in composition with material collected by ROV or video assisted grab. [ABSTRACT FROM AUTHOR]

Deep-water Oculina coral reefs, which are similar in structure and development to deep-water Lophelia reefs, stretch 167 km (90 nm) at depths of 60–100 m along the eastern Florida shelf of the United States. These consist of numerous pinnacles and ridges, 3–35 m in height, that are capped with thickets of living and dead coral, Oculina varicosa. Extensive areas of dead Oculina rubble are due in part to human impacts (e.g., fish and shrimp trawling, scallop dredging, anchoring, bottom longlines, and depth charges) but also may be due in part to natural processes such as bioerosion, disease, or global warming. In the 1970s, the reefs were teeming with fish. By the early 1990s, both commercial and recreational fisheries had taken a toll on the reefs, especially on the coral habitat and populations of grouper and snapper. In 1984, 315 km2 (92 nm2) was designated the Oculina Habitat of Particular Concern (OHAPC), prohibiting trawling, dredging, bottom longlines and anchoring, and establishing the first deep-sea coral marine protected area in the world. In 2000, the Oculina Marine Protected Area (MPA) was expanded to 1029 km2 (300 nm2). Despite these protective measures, manned submersible and ROV observations in the Oculina MPA between 1995 and 2003 suggest that portions of the coral habitat have been reduced to rubble since the 1970s, grouper spawning aggregations may be absent, and illegal trawling continues. This paper is a review of the results of the mapping, habitat characterization, and fish surveys from the early historical studies (1960–1980s) to the more recent surveys (1995–2003). [ABSTRACT FROM AUTHOR]

The Belgica Mound province is one of three provinces where carbonate mounds are associated with cold-water coral species in Porcupine Seabight, west of Ireland. Building upon extensive existing datasets, the Polarstern ARK XIX/3a cruise, deploying the robotic submersible VICTOR6000 (ROV), was undertaken in June 2003. This paper presents an overview of preliminary results from a reconnaissance video survey over and between several steep-flanked Belgica Mounds (giant mounds) and from a microbathymetric survey over some smaller mounds (Moira Mounds). Visual evidence for a strong hydrodynamic regime in the vicinity of the carbonate mounds is found with the interaction between currents and sedimentation having an important role in mound growth and development. Only some mounds show a high percentage of live coral coverage although there is a clear increase of megafaunal concentrations and species on mounds. One area of the province (the eastern ridge of aligned mounds) revealed very little live coral cover, asymmetrical drift accumulations burying the eastern sides and sediment-clogged dead coral frameworks at the western sides. This is in contrast to other areas (e.g., the western alignment of mounds) that show abundant live coral cover at present. In nearly all parts of the survey area the impact of fisheries, especially demersal trawling, is noted. [ABSTRACT FROM AUTHOR]

One of the critical information needs identified at the 2003 Deep-Sea Corals Workshop in Galway, Ireland, was to locate and chart deep-sea corals in order to develop reliable estimates of their distribution and abundance. While reports of deep-sea corals from the Gulf of Mexico date back to the 1860s, relatively little is known about their distribution or abundance. This paper attempts to provide a current assessment of the occurrence of Lophelia pertusa and Madrepora oculata in water depths greater than 200 m in the Gulf of Mexico by summarizing records from (1) published material, (2) the 2003 National Museum of Natural History Taxonomic Database, (3) findings obtained during the September-October 2003 NOAA-OE RV Ronald H. Brown cruise RB-03-07-leg-2 in the northern Gulf, and (4) from various unpublished sources. [ABSTRACT FROM AUTHOR]

The habitat-forming scleractinian coral Lophelia pertusa supports an ecosystem that is widely known to occur in the bathyal marine ecologic realm along deep shelves, oceanic banks, seamounts and continental margins. Therefore, L. pertusa is generally considered a ‘deep-water’ or ‘deep-sea’ coral. In contrast, this study analyses the environmental controls of this bathyal ecosystem where it is thriving well in the non-bathyal shallow-water setting of the Swedish Kosterfjord area (NE Skagerrak). This is one of several shallow-water L. pertusa occurrences in Scandinavian waters where saline and temperature stable oceanic waters intrude as topographically-guided underflows onto the inner shelf and adjacent fjords, driven by an estuarine circulation. The L. pertusa occurrence of the Säcken site in the northern Kosterfjord exists at 80–90 m water depth and only a few tens of metres beneath a permanently brackish surface water layer. At the depth of the coral patches, however, the hydrographic data reveal fully marine conditions, which are ensured by a deeper inflow of Atlantic water through the Norwegian Trench into the Skagerrak. SEM analyses of resin casts taken from dead L. pertusa skeletons yield an endolith assemblage dominated by boring sponges such as Cliona spp. (trace: Entobia ispp.), the boring bryozoan Spathipora, the fungus Dodgella priscus (trace Saccomorpha clava) and an unknown fungus (trace: Orthogonum lineare). Such a composition exclusively of heterotroph organisms resembles the Saccomorpha clava / Orthogonum lineare ichnocoenosis which is regarded as indicative for fossil and Recent, open marine, aphotic environments. This interpretation is supported by direct light measurements at the Säcken site, which indicate aphotic conditions for at least most of the year. The finding of bathyal communities in comparatively shallow waters is linked to factors that force deeper oceanic water masses to surface. Such situations are likely to be expected where an estuarine circulation prevails, or in deep-sea basins bordered by narrow shelves and with local upwelling cells driven by the wind regime, facilitating the intrusion of eutrophic deeper waters to shallow depths — including the benthic communities. This circumstance reveals a major potential pitfall in the palaeobathymetric interpretation of fossil L. pertusa occurrences, which tend to be interpreted as bathyal palaeoenvironments. Strikingly, almost all known exposed ancient L. pertusa locations (e.g. Rhodes and Messina Strait in the Mediterranean Sea or the Cook Strait, New Zealand) derive from tectonically active regions with steep bathymetric gradients and a specific confined topography which could have forced deep water to the near surface. [ABSTRACT FROM AUTHOR]

Samples of Lophelia were taken at two localities in the Lindos Bay Clay (Lower Pleistocene) of the Rhodes Formation on the Dodecanese Island of Rhodes. At a coastal exposure at Vasphi, northeast Rhodes, about 200 fragments of Lophelia were collected in situ from the clay and surface preservation of these is consequently particularly fine. The second collection of material was made at an exposure south of Lardos, about 35 km further south. This material comprised some 800 fragments of Lophelia collected both in situ and loose; preservation quality of the surfaces of these is variable. Both collections derive from single fl at beds of coral fragments. Bioerosion of the corals shows a good diversity, comprising about 18 ichnotaxa, five in open nomenclature, including: Orthogonum lineare, Saccomorpha clava and other microborings (probably exclusively of endolithic fungi), Oichnus isp. (pits and holes of various forms, probably all deriving from foraminifers), dish-shaped etchings possibly produced by the foraminifer Hyrrokkin sarcophaga, Palaeosabella prisca (polychaete worm borings), Caulostrepsis isp. (polychaete borings), probable Maeandropolydora isp. (polychaete borings), Talpina isp. (phoronid borings), Podichnus centrifugalis (attachment scars of brachiopods), Centrichnus eccentricus (attachment scars of anomiid bivalves), Gnathichnus pentax (tooth scratches by regular echinoids), and Entobia ispp. (borings of endolithic sponges). Three small, radiating forms around a millimetre in size are difficult to attribute to particular tracemaking organisms. They are retained in open nomenclature as Semidendrina-form (possibly foraminifera borings), a non-camerate radiating form and a hirsute camerate form. No ctenostome bryozoan borings were observed. Talpina isp. is abundant at Vasphi but scarce at Lardos. Otherwise the relative abundance of the trace fossils is comparable at the two localities. The total amount of bioerosion varies considerably in different parts of the coral skeleton. On the basis of SEM imagery, three categories of bioerosional intensity are introduced: 1, slight bioerosion; 2, medium bioerosion, and 3, heavy bioerosion. The distribution of Gnathichnus pentax and the absence of Radulichnus inopinatus indicates an aphotic environment. The microbioerosional assemblage correlates with the Saccomorpha clava / Orthogonum lineare Ichnocoenosis, which also indicates an aphotic seafl oor. [ABSTRACT FROM AUTHOR]

This study focuses on bioerosion of an aphotic deep-water coral mound, the Propeller Mound, in the northern Porcupine Seabight. The predominant framework builder is the cosmopolitan cold-water coral Lophelia pertusa. We demonstrate bioerosion patterns within the skeleton of L. pertusa using a new embedding method under vacuum conditions with subsequent scanning electron microscope analysis. Following this method, 23 ichnospecies are documented and related to heterotrophic organism groups such as Bacteria (1), Fungi (12), Bryozoa (1), Foraminifera (3), and Porifera (6). Predominant endolithic sponges in the framework of L. pertusa are Alectona millari and Spiroxya heteroclita. Owing to its characteristic growth and surface ornamentation, trace casts of Spiroxya heteroclita are correlated to the well-known trace fossil Entobia laquea. Investigations of thin sections of post-mortem skeletons show a clearly pronounced endolithic tiering of three penetration depths. The analysed samples are divided into three macroscopic preservational stages differing in post-mortem age, and exposure of the framework. Bioerosion affects bare parts of the coral skeleton. Bioeroders preferably settle on one side of an upright growing colony. A succession usually starts with the infestation by bacteria and fungi. Contact zones of epiliths are preferred areas for penetration by endoliths. Sponges and foraminifers appear 10 cm below the zone of living polyps, followed by boring bryozoans 15 cm below. However, in one case the sponge Spiroxya heteroclita is documented in the skeleton of living polyps. Frameworks exposed to water host 19 ichnospecies, thus forming the most diverse ichnocoenosis, whereas nine ichnospecies are documented in coral specimens buried by sediment. Mapping of epi- and endoliths in living and freshly necrotic colonies represents a useful tool for monitoring environmental conditions and define ecological “health” of deep-water corals in a rapid large-scale assessment of the state of coral reefs. [ABSTRACT FROM AUTHOR]

An overview of preliminary results from a series of recent Remotely Operated Vehicle (ROV) dives on the deep-water coral provinces of the Porcupine Bank, Irish continental margin, NE Atlantic is presented. The Porcupine Bank exhibits numerous giant carbonate mounds (up to 100s of metres in height) that occur predominantly, although not exclusively, on topographic ridges. The results revealed that, although these ridges have a tectonic origin, contemporaneous activity is typified by erosion due to strong hydrodynamic controls. The carbonate mounds are colonized by a variety of suspension feeders and associated fauna including framework-building corals (e.g., Lophelia pertusa and Madrepora oculata) although dense coral reef-like fauna coverage is not evident at present. The ecology of the carbonate mounds varied widely. Sessile megafauna, such as sponges, gorgonians and framework-building corals (e.g., Lophelia pertusa), were abundant on some of the carbonate mounds. Other mounds were relatively barren and appeared to be undergoing a natural senescence, with a much lower biomass of megafauna than is typical of shallow-water coral reefs. Some mounds had been damaged by demersal trawls, with smashed coral and lost gear common, whereas others appeared relatively pristine with occasional evidence of man-made litter. [ABSTRACT FROM AUTHOR]

The Davidson Seamount is located 120 km to the southwest of Monterey, along the California coast, USA. It is 2,400 m tall; yet, it is still 1,250 m below the sea surface. In May 2002, 90 hours of digital video was recorded from all depths of the Davidson Seamount, using a remotely operated vehicle, and deep-sea coral specimens were collected. Preliminary analyses indicate that 20 coral taxa were found, and they were almost exclusively located in high relief, ridge areas. Other species were noted on or adjacent to the corals. Because of its pristine nature, as well as human threats and great potential for education, the Davidson Seamount is under consideration for protection as part of the Monterey Bay National Marine Sanctuary. [ABSTRACT FROM AUTHOR]

There is much debate about how to protect deep-sea coral and sponge ecosystems using the data currently available. The Aleutian Islands in Alaska contain some of the most abundant, diverse, and pristine deep-sea coral and sponge ecosystems on Earth. From 1990 to 2002, U.S. federal fishery observer data indicates approximately 2,176,648 kg of coral and sponge bycatch occurred in the Aleutian Islands, equaling 52 % of all coral and sponge bycatch in Alaska. Coral and sponge bycatch rates in the Aleutians were over 12 times the rate in the Bering Sea or Gulf of Alaska. The National Marine Fisheries Service (NMFS) estimates that 87 % of coral bycatch and 91 % of sponge bycatch is caused by bottom trawling in the Bering Sea/Aleutian Islands management areas. The conservation organization Oceana developed an interdisciplinary fishery management approach to mitigating adverse impacts of fishing on deep-sea coral and sponge ecosystems, which has been used by NMFS to formulate a habitat protection alternative for the Aleutian Islands that is being considered in an Environmental Impact Statement. The Oceana Approach is offered as a cost effective model for reducing the adverse effects of fishing on deep-sea coral and sponge ecosystems. The approach uses observer data to identify areas of high coral and sponge bycatch rates to develop a comprehensive management policy that allows bottom trawling only in specific designated areas with high fish harvest and low habitat impacts. All areas not specified as open would be closed to bottom trawling. To prevent effort displacement, bottom trawl effort is reduced by the amount that historically occurred in areas that would become closed. The Oceana Approach also includes coral and sponge bycatch limits and a plan for comprehensive seafloor research, mapping, and monitoring. An enforcement strategy for these management measures is developed based on agency capabilities, and includes increased observer coverage, vessel monitoring systems, and electronic logbooks. This approach allows for continued catch of target species with minimal adverse impacts on coral and sponge habitat. Successful implementation of the Oceana Approach will protect areas of high known trawl impacts to deep-sea coral and sponge ecosystems and prevent trawl effort from moving into new, unexplored areas. The methodology is recommended for application to other regions and should be adjusted based on the available fishery and biological data for each region. [ABSTRACT FROM AUTHOR]

The deep-sea (>200 m) represents the largest portion of the ocean, but it is probably the least understood because of the technological challenges and financial resources required to explore and research this environment. With the advancement of underwater technology, astonishing images of deep-sea corals living at depths from the surface to greater than 1000 m are now becoming available to both policy makers and the public. More specifically, in the North Atlantic Ocean, these images have led many countries to begin to assess the distribution, status, health, and potential threats faced by these important ecosystems, which appear to be connected by the uniting influence of the Gulf Stream and its associated currents. Since deep-sea coral ecosystems extend beyond national boundaries and encounter similar threats, it was determined that a cooperative effort on both sides of the Atlantic could be beneficial to maximize available resources, share expertise, and exchange data to rapidly increase scientific understanding of deep-sea coral ecosystems. Thus, an international Deep-Sea Corals Workshop was held to identify critical information needs related to: locating and mapping deep-sea corals; understanding more about coral biology and ecology; and using specific deep-sea coral species as indicators of climate change. Priority information needs identified at the workshop were the need to: (1) conduct both low- and high-resolution mapping to locate and characterize deep-sea coral habitats; (2) conduct research on factors that influence deep-sea coral life history patterns; (3) examine how they function as habitat for fish and invertebrate species; (4) develop a comprehensive inventory of deep-sea coral species; and (5) further efforts to analyze past climate changes and to improve climate forecasting models. Described herein are: the results of the Deep-Sea Corals Workshop; other events with a focus on deep-sea corals; and potential pathways to increase U.S.-international collaborative partnerships. [ABSTRACT FROM AUTHOR]

Zooxanthellate scleractinian corals have been shown to preserve important archives of seasonal variations of climate variables, such as sea surface temperature, salinity, and productivity. By analogy, the recognition of correlated chemical signals in azooxanthellate deep-water corals may provide an important new approach to help unravel the role of intermediate and deep waters in determining climate variability. A first step to determine the suitability of deep-water scleractinian corals as potential paleoceanographic-paleoclimatic tools requires the demonstration of coherent geochemical signals in their skeletons. With this in mind, trace and minor element ratios Sr/Ca, Mg/Ca, U/Ca, B/Ca, P/Ca, Ba/Ca and Mn/Ca have been measured in two deep-water solitary scleractinian corals (Desmophyllum dianthus) collected from Last Glacial submerged banks in the Mediterranean basin and in the Great Australian Bight. Most elements show distinct, highly correlated patterns of variation. Although preliminary, these results illustrate the potential use of trace and minor element concentrations in the deep-water scleractinian corals to provide new constraints on the composition and evolution of intermediate and deep waters and thus introduce new perspectives in paleoceanography, such as the assessment of changes in both deep-sea nutrient chemistry and ocean circulation. [ABSTRACT FROM AUTHOR]

The longest available time series on ocean currents indicates that the southward flow of water from the Greenland Sea is weakening, and that correlative large-amplitude changes have occurred in the rate of formation of intermediate Labrador Sea water. These have been linked to changes in regional climate which, if trends continue, could within 30 years alter the flow of the North Atlantic Drift and possibly interrupt the formation of Labrador Sea water, profoundly affecting regional climates, marine ecosystems and fisheries. We are attempting to use the carbonate skeletons of cold-water corals to find out how rapidly and how often the thermohaline circulation of the NE vs. NW Atlantic has changed in the past, just as tree rings and ice cores are used to investigate climate change on land. We have focussed on the NE Atlantic for our preliminary work, notably the Faroe-Shetland Channel: a major gateway between the Atlantic Ocean and the Norwegian Sea. Warm North Atlantic Drift water passes north through this channel on the surface, warming northern Europe. Cold Norwegian Sea Overflow Water returns at depth, contributing to the formation of North Atlantic Deep Water. Existing records are too short to allow conclusions regarding recent temporal changes in this inflow, so proxies are sought. We have analysed live-collected Lophelia pertusa skeletons collected in October 2001 using a ring dredge from RV Scotia along the worlds longest-running hydrographic transect (from 1893). Corals were sectioned using a slow-speed Isomet saw, and sampled for isotopic analysis using a Merchantek micromill. Observation of sectioned corals revealed dense-less dense couplets, as in every coral studied to date from tropical to deep cold-water environments worldwide. We sampled circumferentially, in the centres of individual bands, so as to produce temperature estimates using the “lines” technique of Smith et al. (2000). The results were simultaneously encouraging and confusing. Each of the coral samples generated lines from which temperatures could be estimated. Dense skeletal bands had lower temperatures than the less-dense bands, hence we conclude these were winter and summer bands, respectively. The mean annual temperature (MAT) range determined from one of the corals was 3.8°C. Pooling results from several corals yielded a lower estimate for MAT range: 2.3°C. The absolute temperatures from the corals, however, were somewhat lower than the instrumental record with “winter” records being more depleted than the “summer values”. This was unexpected and shows that determining detailed climate records from L. pertusa may be more difficult than hoped. [ABSTRACT FROM AUTHOR]

Like other biogenic carbonate that can be dated, aragonite skeleton of deep-sea corals is a potential archive of oceanographic changes over time. Stable isotope analysis is commonly used in paleoceanographic reconstruction of past seawater temperatures, however, offset from isotopic equilibrium as well as recent observations about isotope distribution with the micro-structure of deep-water corals implies non direct paleoclimate reconstructions. Here we test the influence of the sampling scale on oceanographic interpretations. The stable isotope composition for different modern calyxes of Lophelia pertusa has been analyzed at different scales using either a macro or a micro-sampling technique. The comparison of the obtained results from the two sampling techniques shows that the isotopic variability observed with the micro-sampling is twice the one with macro-sampling. Moreover the macro-sampling is not an average of what happens at a more precise scale. Nevertheless a realistic seawater temperature estimate can be retrieved using the equation of Smith et al. (2000) for both the macro and the micro-sampled corals. However, a test of the reproducibility on a single calyx reveals important isotopic inhomogenities at a very fine scale (∼µm), yielding an external reproducibility of the seawater temperature estimates of about ±0.7°C for micro sampled corals. [ABSTRACT FROM AUTHOR]

It has been suggested that the deep-sea gorgonian coral Primnoa resedaeformis may be an important paleoceanographic archive. Seventeen colonies collected from the upper slope of the NW Atlantic margin (229 – 447 m) were analyzed to see if skeletal Mg/Ca is related to temperature. Analyses were focused on the calcite cortex region of skeletal sections to avoid interference from organic Mg in the horny layers found closer to the center of sections. Comparison of bulk skeletal Mg/Ca with hydrographic temperature yielded the relationship Mg/Ca (mmol/mol)=5 (+/− 1.4) T (°C)+64 (+/− 10). This relationship was used to calibrate profiles of Mg/Ca measured across the annual rings of one large, well-dated colony, over the period 1950–2002. Mg/Ca profiles were broadly consistent among three sections spaced 10 cm apart along the main trunk of the colony. These profiles were in general agreement with the local instrumental record of temperature at 375 – 450 m. Some discrepancies between the coral and instrumental records of temperature may be a result of chronological error, poor sampling density, or additional factors influencing Mg partitioning in the coral. Overall, these preliminary results support the hypothesis that temperature drives Mg/Ca in the skeletal calcite of this species. It appears that environmentally meaningful records from Primnoa resedaeformis will be found at decadal scales or longer. [ABSTRACT FROM AUTHOR]

Two samples of the calcitic deep-sea coral Primnoa resedaeformis have been analysed for Mg/Ca ratios by micro-beam methods ( laser-ablation ICP-MS and electron microprobe). Continuous profiles of Mg/Ca have been studied with the aim of establishing the reproducibility of the variations in different parts of the coral, and therefore the potential use of Mg/Ca as a paleoceanographic or paleoclimatic tracer. A method of spectral decomposition based on box-filter smoothing has been developed for analysing the signals. This method shows that all profiles measured contain some degree of irreproducibility. Much of this irreproducibility appears to be white-noise added by the analytical methods. The amplitude of this noise is around 15 % of the signal average for the Nd-YAG laser-ablation system at Memorial University of Newfoundland, 5–6 % for the electron microprobe at Dalhousie University, and 4–4.5 % for the ArF Excimer laser-ablation system at the Australian National University. In the case of the LA-ICP-MS analyses, this noise may relate to uneven ablation of material from the coral and/or an uneven size distribution of particles entering the ICP-MS plasma. For the most stable system (ANU’s LA-ICP-MS), features on distance scales smaller than 150–200 µm will be obscured by the noise, and features smaller than 500 µm should be interpreted with caution. There is some evidence that the coral itself contains compositional heterogeneity, although reproducibility is mostly limited by instrumental noise. We recommend that several analytical profiles be compared before any attempt is made to interpret Mg/Ca variations in terms of paleoceanographic changes. [ABSTRACT FROM AUTHOR]

Lophelia pertusa is a deep-sea scleractinian coral (azooxanthellate) found on the continental margins of the major world oceans. Built of aragonite it can be precisely dated and measured for stable isotope composition (C–O) to reconstruct past oceanic conditions. However, the relation between stable isotope and skeleton microstructures, i.e. centres of calcification and surrounding fibres, is crucial for understanding the isotopic patterns. Values for δ18O and δ13C in Lophelia pertusa were determined at a micrometer scale using an ion microprobe (SIMS - Secondary Ion Mass Spectrometry). In this coral species, centres of calcification are large (50 µm) and arranged in lines. The centres of calcification have a restricted range of variation in δ18O (−2.8 ± 0.3 ‰ (V-PDB)), and a larger range in δ13C (14.3 to 10.9 ‰ (V-PDB)). Surrounding skeletal fibres exhibit large isotopic variation both for C and O (up to 12 ‰) and δ13C and δ18O are positively correlated. The C and O isotopic composition of the centres of calcification deviate from this linear trend at the lightest δ18O values of the surrounding fibres. The fine-scaled variation of δ18O is probably the result of two processes: (1) isotopic equilibrium calcification with at least 1 pH unit variation in the calcification fluid and (2) kinetic fractionation. The apparent δ13C disequilibrium in Lophelia pertusa may be the result of mixing between depleted δ13C metabolic CO2 (respiration) and DIC coming directly from seawater. This study underlines the close relationship between microstructure and stable isotopes in corals. This relationship must also be taken into consideration for major elements like Mg and trace elements (U-Sr-Ba) increasing the reliability of the geochemical tools used in paleoceanography. [ABSTRACT FROM AUTHOR]

Benthic Foraminifera found attached to the deep-sea coral Primnoa resedaeformis may be used to establish paleo-coral locations long after the coral has disappeared. Recent coral research cruises have revealed that the coral on the Scotian Margin is in peril and in many cases no longer exists. Sea floor video footage suggests various fishing methods have destroyed much of the coral as it has in coastal areas off Norway and Alaska. To date deep-sea corals are sparse on the Scotian Margin; therefore evidence preserved in the sediment may establish whether corals were present and more abundant in the past. A representative assemblage of benthic foraminiferans found attached to the deep-sea coral Primnoa resedaeformis may be the evidence necessary to provide presence/absence indicators long after the coral has disappeared. Both foraminiferal species are known to be only associated with the coral, and distortion of the ventral side (attached) of common foraminiferal species found in the sediment, may provide a clue to past coral habitat. Identifying a deep-sea coral paleo-habitat indicator provides insight into the extent to which it existed. Video footage from coral cruises over the last three years indicates that coral and fish go hand in hand, an important observation for a region where fishing comprises 23 % of the local economy. Twenty-eight foraminiferal species were found in a range of abundances on nine deep-sea coral specimens of Primnoa resedaeformis. Attached foraminiferans are found on the basal sections of the coral where they colonize onto the hard calcite substrate. One of the more common and consistent foraminiferal species found attached to the coral, Discanomalina semipunctata, is not found commonly on the continental margin in non-coral areas and may provide in situ evidence of past coral habitat. [ABSTRACT FROM AUTHOR]

The rate of discovery of reefs of the cold-water coral Lophelia pertusa (Linnaeus, 1758) has been remarkable, and attributable to the increased use of underwater video. These reefs form a major three-dimensional habitat in deeper waters where little other ‘cover’ for fish is available. They are common in the eastern North Atlantic, and occur at least in the western North Atlantic and off central Africa. There are also other non-reef records of Lophelia in the Atlantic, and in Indian and Pacific oceans. Thus, not only are these reefs a significant habitat on a local scale, but they may also provide an important habitat over a very wide geographic scale. The present study examined the association of fish species with Lophelia in the Northeast Atlantic, including the Trondheimsfjord and Sula Ridge in Norway, Kosterfjord in Sweden, Darwin Mounds west of Scotland, and Rockall Bank, Rockall Trough and Porcupine Seabight off Ireland. The fish fauna associated with a shipwreck west of Shetland was also studied. Data were collected from 11 study sites at 8 locations, using 52 hours of video and 15 reels of still photographs. Video and still photographs were collected from (1) manned submersible, (2) surface controlled remotely operated vehicle (ROV), (3) a towed “hopper” camera, (4) wide angle survey photography (WASP), (5) seabed high resolution imaging platform (SHRIMP), and (6) an in situ time-lapse camera “Bathysnap”. It was possible to identify 90 % of fish observed to species level and 6.5 % to genus or family level. Only 3.5 % of the fish were not identifiable. A guide to the fishes is given at http://www.ecoserve.ie/projects/aces/. Twenty-five species of fishes from 17 families were recorded over all the sites, of which 17 were of commercial importance and comprised 82 % of fish individuals observed. These commercial fish species contribute 90 % of commercial fish tonnage in the North Atlantic. The habitats sampled were comprised of 19 % reef, 20 % transitional zone (i.e. between living coral and debris zone), 25 % coral debris and 36 % off-reef seabed. Depth was the most significant parameter in influencing the fish associated with the reefs, both at the species and family level. There was a complete separation of sites above and below 400–600 m depth by multi-dimensional scaling (MDS) analysis. Less distinct assemblages of fish species were associated with each habitat. Fish species richness and abundance was greater on the reef than surrounding seabed. In fact, 92 % of species, and 80 % of individual fish were associated with the reef. The present data indicates that these reefs have a very important functional role in deep-water ecosystems as fish habitat. [ABSTRACT FROM AUTHOR]

Deep-sea dredging of sediment-starved steep reliefs in the Strait of Sicily (cruise CS96 of RV Urania) recovered various benthic organisms previously unknown or poorly documented in the Mediterranean basin. This Mediterranean case-study refers to deep coral substrates represented by loose or cemented skeletal remains of Desmophyllum, Lophelia and Madrepora, subfossil giant oyster shells, micriticised sponges, from c. 250–1000 m depth. Here we present some of the more remarkable species: one foraminiferan (Planogypsina?); the sponges Stylocordyla pellita, Sphinctrella gracilis and Siphonidium ramosum; a bioluminescent zoantharian (still unidentified); the boring actinian Fagesia loveni; the stoloniferous octocoral Scleranthelia musiva; the gorgonian Dendrobrachia fallax; and the holothurian Psolidium complanatum. [ABSTRACT FROM AUTHOR]

Seamounts are drowned volcanoes rising from abyssal depths. Fishes on seamounts exploit a range of landscape features that likely enhance probabilities of prey capture and reduce predator success. The epifaunal community on seamounts is dominated by suspension-feeders of which deep-water corals are a dominant element. Such taxa are widespread components of seamount landscapes but their functional role in mediating the distribution and abundance of fishes remains unknown. Here we propose a hierarchical habitat classification matrix, which includes deep-water corals, as a foundation for partitioning seamount landscapes in which fishes are observed. This scheme is based on our observations of fish distributions from the New England Seamounts, as well as literature review. Features of an idealized seamount landscape were divided at multiple spatial scales and included features at habitat class, subclass and microhabitat levels. Habitat classes were divided by major sediment types (i.e., basalt, fine grained sediments). Habitat subclasses included pavement, ridges, walls, ledges and tubes for basalt substrates and flat sediment, ripples and waves for fine-grained sediments. Microhabitat features were classified as flow related features, emergent structures (i.e., geologic and biologic including deep-water corals), and other biogenic structures (e.g., coral debris, depressions, burrows). Variations in the distribution of structures at multiple spatial scales can influence boundary flows and the ability of fishes to search for prey (e.g., where active searching by swimming can occur, where pelagic prey delivery is sufficient when station-keeping) and avoid predators (e.g., the ability to efficiently exhibit various avoidance behaviors such as shelter seeking). Placing fish abundance data in such a matrix of habitat types enables a variety of statistical approaches for testing for non-random distributions of fishes on seamounts and quantifying the functional role of corals as fish habitat. [ABSTRACT FROM AUTHOR]

The metazoan meiofauna associated with Lophelia pertusa reef degradation zones in the Belgica Mound province (Porcupine Seabight, North-East Atlantic) was studied in the framework of the Atlantic Coral Ecosystem Study (ACES; EC Fifth Framework Research Program). Attention was focused on the influence of and differences between different microhabitat types: dead coral fragments, glass sponge skeletons and the underlying sediment. This study demonstrates the importance of dead Lophelia pertusa framework and associated substrates for meiofauna along the European continental margins. The presence of these large biogenic structures on the seafloor of the continental margin (1) enables more taxa to be present and (2) particularly favours harpacticoid copepods, naupliar larvae and polychaetes. The meio-epifaunal community on these substrates significantly differs from the meio-infaunal community in the underlying sediment. This is mainly due to a much lower dominance of nematodes and a higher relative abundance of most other taxa, especially harpacticoids, naupliar larvae and polychaetes, in the latter habitat. This situation is comparable to that of epiphytic assemblages. Dominance of nematodes is low. The meio-infaunal assemblage in the underlying sediment is characterized by low densities. There are clear indications that cold-water coral degradation zones are biologically very diverse, in terms of species richness as well as equitability. Of all microhabitat types, coral fragments support the most diverse communities, whereas the underlying sediment is the least diverse. [ABSTRACT FROM AUTHOR]

High densities of fishes in aggregations of deep-water corals (e.g., of the genera Primnoa, Paragorgia, Paramuricea) do not necessarily indicate that corals are important habitats in terms of population processes. Frequency dependent distribution models provide a basis for assessing the role of deep-water corals. It is necessary to understand the overall habitat-related distributions of fish species, at particular life history stages, in order to assess the particular role of corals. Examining the landscape for ecologically equivalent habitats is one approach for assessing the importance of coral habitats. Measures of the functional equivalence of habitats are demonstrated, as an example, for sites from the Gulf of Maine on the northeast United States continental shelf. Fish census data based on surveys with a remotely operated vehicle in 2003 showed that communities in habitats dominated by dense corals and dense epifauna were functionally equivalent when compared with five other less complex habitats (e.g., boulder with sparse coral cover). Comparison of species-individual curves showed that sites with dense coral and dense epifauna habitats supported only moderate levels of fish diversity when compared with other sites. Further, density of Acadian redfish (Sebastes fasciatus) in dense coral and dense epifauna habitats, where this species was dominant, was not statistically different but was higher than an outcrop-boulder habitat with sparse epifauna (the only other site where this species was abundant). Such data suggest that coral habitats are not necessarily unique but have attributes similar to other important habitats. However, the level of their importance in the demography of fish populations and communities remains to be demonstrated. Focusing conservation efforts for deep-water corals on their perceived value to exploited species, without good demographic information on fish populations, may ultimately leave corals open to destructive fishing practices if new and contrary information emerges. Conservation efforts for corals, in the absence of explicit ties to managed fish species, might do better emphasizing the intrinsic value of corals, their slow growth, high sensitivity to disturbance, and the questionable potential for recovery. [ABSTRACT FROM AUTHOR]

Colonial non-zooxanthellate corals from deep-water coral reefs, Lophelia pertusa and Madrepora oculata, produce large amounts of extracellular mucus (EMS). This mucus has various functions, e.g., an antifouling capability protecting the coral skeleton from attacks of endolithic and boring organisms. Both corals show thick epithecal and exothecal skeletal parts with a clear lamellar growth pattern. The formation of the epitheca is unclear. It is supposed that the EMS play a central role during the calcification process of the epithecal skeletal parts. Staining with the fluorochrome tetracycline has shown an enrichment of Ca2+ ions in the mucus. In order to investigate this hypothesis, the protein content of the mucus and the intracrystalline organic matter from newly formed epithecal aragonite of Madrepora oculata was determined via sodium dodecyl sulfate (SDS) gel electrophoresis. Identical band patterns within both substances could be detected, one around 45 kDa molecular weight and a cluster around 30–35 kDa molecular weight. The occurrence of identical protein patterns within the mucus and in the newly formed aragonite confirms the idea that the mucus plays an important role during the organomineralization of the coral epitheca. [ABSTRACT FROM AUTHOR]

A number of reefs are found along the coast of northern Norway, and a cluster of particularly high reefs off Troms County at 70°N are known collectively as the Fugløy Reef. The reefs, up to 40 m high and more than 200 m wide, consist mainly of the reef-building Lophelia pertusa. Most of the reefs identified in the study area are located on moraine ridges in water depths of 140–190 m, and in water masses dominated by the relatively warm and saline Norwegian Current. Several of the reefs are located on the flanks of channels incising the moraine highs, where currents are tidally dominated and periodically reach velocities of 30 cm/s. Gravity cores were acquired from the reefs and their surroundings, and thorough analyses of the sampled sediments provide valuable information about three (paleo-) sedimentary environments surrounding the reefs. The immediate vicinity of the reefs consists of coarse and unsorted deposits that are interpreted to be moraine material deposited by the retreating inland ice. Elevated current velocities have prevented fine sediments from settling since the ice retreated. The second province is a pockmarked basin at water depths down to ∼300 m. Gravity cores from the basin reveal silty sand deposits of more than 4 m thickness representing postglacial sedimentation in the area. Gas analyses reveal that the hydrocarbons found in the sediments clearly are of biogenic origin, although it is somewhat enigmatic whether biogenic gas is the sole driving force behind the pockmarks in the area. No direct link between the reefs and the pockmarks is found. The third sedimentary province is characterised by resedimentation of coral debris, clearly illustrated by sorted deposits and U/Th-datings from the allochthonous deposits. Remobilisation of coral debris is modest in areal extent, but an important mechanism linked to the occurrence of the coral reefs. [ABSTRACT FROM AUTHOR]

As a result of the explorations carried out by the Colombian Marine and Coastal Research Institute (INVEMAR) between 1998–2002 along the Colombian Caribbean continental shelf and upper slope, the occurrence of azooxanthellate coral banks was suspected at three sites (from the northern to southern Colombian Caribbean coast): off La Guajira Peninsula, at a water depth of 70 m; off Santa Marta, at 200 m, and nearby the San Bernardo Archipelago, at 150 m). Each site exhibited particular bottom features (relief and substrate), suggestive of reef structures. The analysis of the fauna collected by bottom trawling at these sites showed that many of the fishes, mollusks, echinoderms, crustaceans, antipatharians, soft corals and bryozoans collected are characteristic dwellers of hard substrates or reef bottoms. At the first site (Guajira) the hard coral Cladocora debilis, was the most abundant; a total of 156 species of invertebrates and fishes were identified among the material collected at this site. At the second site (Santa Marta), 13 scleractinian species were collected, but Madracis myriaster, was the dominant species; another 102 species of invertebrates and fishes were also found. At the third site (San Bernardo) 19 scleractinian species were found, M. myriaster being the dominant. A total of 135 species of invertebrates and fishes were collected at this site. It is presumed that deep-sea coral banks have developed in these three settings, since many of the collected species are known to be hard or reef bottom dwellers. [ABSTRACT FROM AUTHOR]

Carbonate mounds (up to 200 m high) formed from the accumulated remains of cold-water corals (principally Lophelia pertusa and Madrepora oculata), associated calcareous fauna and interstitial sediment are present at 500–1000 m water depths west of Ireland. Seabed mapping datasets (side-scan sonar, multibeam echosounder, sub-bottom profiler and underwater video imagery) are presented here from the Belgica Mound province on the eastern Porcupine Seabight margin. The data, integrated within a Geographic Information System (GIS), provide an environmental context to mound development. Analysis of this multidisciplinary dataset and resultant facies map highlight differing sedimentary processes (e.g., sediment wave, barchan dune, gravel lag and sand ribbon development) operating under strong northward flowing bottom currents with sandy sediment supply where the influence of mound topography on benthic currents and sediment pathways is evident. Correspondingly, benthic current pathways and associated sediment transport also exert an influence on carbonate mound surface morphology and growth. Giant mounds show a transition from sediment waves that, with increasing coral colonisation, give way to banks of coral towards the mound summits. Smaller mound features (Moira Mounds) show sand entrapment as an important mound-forming process. [ABSTRACT FROM AUTHOR]

Carbonate mounds, identified as deep-water coral banks, have been reported recently from three provinces in the Porcupine Seabight, SW of Ireland. As yet, the mechanisms behind their formation and development are only partly understood. This contribution discusses their seabed appearance and present-day sedimentary environment, based on a large-scale TOBI sidescan sonar mapping carried out in 2002, and on detailed ROV video records from specific sites within the three mound provinces, collected in 2001. The study of the present-day characteristics and variability of these mounds can help to understand their development history in the past. The imagery clearly shows that the sedimentary environment in the Magellan and Hovland Mound provinces in the northern Porcupine Seabight is much quieter than in the current-swept Belgica Mound province on the eastern flank of the basin. In the latter area, for example, gravel lags and coarse sediments are found, together with patches of sorted sands, striations, barchan dunes and sediment waves. The difference in environment results in different mound appearances. The richest coral communities with the most abundant live coral occurrences are found in the Belgica province, while for example on the Magellan Mounds only a few live coral colonies are left. The present-day situation of the coral banks in the Porcupine Seabight thus illustrates the influence of the interplay between current and sediment dynamics on coral growth and mound development. [ABSTRACT FROM AUTHOR]

Since 1998, Woodside Mauritania Pty Ltd has been exploring for hydrocarbon deposits offshore from the Islamic Republic of Mauritania, in Northwest Africa. A 3-D seismic survey, undertaken in 1999–2000, revealed the presence of buried and seabed carbonate mounds at approximately 450–550 m water depth on the continental slope. These mounds are approximately 100 m in height, 500 m wide at the base, and cover a linear extent of at least 190 km. Core samples from the mounds were found to contain dead fragments of four species of cold-water corals: Lophelia pertusa, Madrepora oculata, Solenosmilia variabilis and Desmophyllum sp. In 2002, a preliminary towed camera survey revealed large areas of coral rubble at two mound sites suggesting that corals were previously a dominant component of the benthic community. A second video survey, in 2003, recorded some live hard coral polyps and a single live coral colony, probably L. pertusa, at one of the mound sites. Coral rubble at all sites surveyed was found to support epibenthic invertebrate and fish assemblages. The mound areas surveyed may have been exposed to physical impacts that have resulted in damage of coral colonies previously inhabiting these features. Based on the nature of the damage and past and present demersal fishing activity in the region, bottom trawling could have caused these impacts. The discovery of a significant deep-water reefal system offshore Mauritania has implications for future management of trawling and oil exploration activities. These issues are discussed in the context of the potential biodiversity significance and conservation importance of the carbonate mud mounds and their associated biological communities. [ABSTRACT FROM AUTHOR]

The dynamics that occur at the Porcupine Bank, Rockall Trough, are described in relation to the role the bank, and others like it, may play in the development of deep-water corals, such as Lophelia pertusa (L.), which occurs widely in the NE Atlantic. High productivity has been measured over the bank, and it appears that this productivity may be fuelled by an increase in nutrients available over the bank through winter convection which leaves dense, nutrient rich water on the bank. This dense water drains away slowly through the benthic boundary layer (BBL) providing a mechanism for downslope transport of organic material in the boundary layer. Processes such as rectification of diurnal tides and Taylor column formation generate closed circulation patterns around the bank and promote the retention of organic matter over the bank. Similar processes have been observed over other Rockall Trough banks, and the combination of these processes appear to promote the availability of food to the corals that inhabit the lower flanks of the banks, particularly on the coral-dominated carbonate mounds that also occur there. [ABSTRACT FROM AUTHOR]

The environmental sensitivies of cold-water corals and their associated biota are likely to be determined by the natural variability of the cold-water coral reef environment. The sensitivity of reef biota to sedimentation and resuspension events is largely unknown and the influence of seasonal phytodetrital deposition is poorly understood. Here we describe the use of a benthic photolander to monitor this variability by the Sula Ridge reef complex on the mid-Norwegian continental shelf and from the Galway carbonate mound in the Porcupine Seabight. The photolander provides a platform for time-lapse digital and film cameras to image the seabed while recording the current regime and optical characteristics (light transmission, backscatter and fluorescence) of the seawater. In its first two deployments carried out in 2001 and 2002 by the Sula Ridge the lander recorded a dynamic environment around the reef site with a tidal current regime and periods of sediment resuspension. Current speeds by the Sula Ridge reef complex reached a maximum of 28 cm s−1 and 70 cm s−1 on the Galway carbonate mound, reinforcing much speculation about the dependence of these communities on current-swept conditions. Seabed photographs show intense feeding activity of echiuran worms (Bonellia viridis) near the Sula Ridge reef complex pointing to rapid bioturbation of the sediment. Fish were recorded sheltering near sponges that had colonised glacial dropstones. Longer term monitoring in situ is needed for study of seasonal change, to identify functional roles of associated fauna and to monitor potential coral spawning events. Benthic landers and seafloor observatories have great potential in these areas. Only with a better understanding of the natural variability of the cold-water coral environment can informed decisions about the environmental sensitivity of cold-water coral reefs and their management be made. [ABSTRACT FROM AUTHOR]

The benthic deep-water coral fauna of the Shiribeshi Seamount, Japan, was examined using the JAMSTEC video archives of four submersible dives in July 2001. An observational dataset containing n = 2055 records was obtained. The vertical distributions of the deep-water gorgonians Family Primnoidae and Paragorgiidae were determined. Primnoid corals include at least one species, Primnoa resedaeformis pacifica (Kinoshita, 1907) and are distributed between 1030 m and 271 m in depth and at a water temperature of 0.24–1.11°. Paragorgiid corals were observed between 491 m and 178 m in depth and at a water temperature of 0.66–1.69°, in shallower and warmer areas than primnoid species. It was observed that deep-sea gorgonians on the Shiribeshi Seamount in the North-West Pacific region exhibit family zonation and vertical distribution patterns. The distribution of hydrocorals, unidentified sponges, shrimp, and nudibranchs was also recorded. This is the first report on a deep-sea gorgonian coral community inhabiting Japanese waters. [ABSTRACT FROM AUTHOR]

A database of deep-water alcyonacean records has been assembled using information that reaches back to the work of A.E. Verrill from the 1800s. These database records fall into two time periods, those from 1874 to 1920, and from 1950 to 2001. A total of 25 species in 10 families are so far known from the northeastern U.S. Most of these species are common in deeper waters of the continental shelf, with a few being restricted to the canyons and other slope environments. A comparison of western and eastern North Atlantic records indicates there is little similarity between the regions. In the cold-temperate to boreal part of the region there is about 41 % similarity of the “stoloniferous” and “massive body” soft coral species, but only about 28 % similarity amongst all the “gorgonian” species. In the warm temperate part of the region the similarity for all groups is less than 10 %. Deep-water alcyonaceans are strongly impacted by bottom fishing gear so it is likely that modern distributional records will not be exactly similar to those from deep in the past. [ABSTRACT FROM AUTHOR]

The Institute of Marine Research commenced a program for mapping and assessment of Lophelia reefs in 1997. It was initiated by reports from fishermen claiming that bottom trawling damaged deep-water coral reefs. The strategy was to survey coral sites reported in the literature and by the fishermen. This has provided an extensive database of coral occurrences, both damaged and undamaged sites. A number of major coral reefs have been identified, which has provided a better understanding of the morphology of Lophelia reefs and where they are likely to occur. We are now able to identify potential coral areas by analysing seafloor topography on maps. Fast and reliable ground-truthing methods using simple and inexpensive systems have been developed. Mapping and quantification of corals demand more advanced instrumentation, such as singlebeam and multibeam echo sounders in combination with data processing software allowing coral reefs to be detected in real time. Systems providing real time presentation of multibeam data are especially useful in combination with Remotely Operated Vehicle (ROV) positioned with acoustic navigation systems. We suggest the following mapping procedure: 1) acoustical reef detection followed by multibeam mapping, preferably along with collection of seismic reflection data. 2) ground-truthing with a tethered video camera platform or an ROV. The position of the observation platform is plotted online and draped on the multibeam maps, either in 2D or 3D mode. Examples from the reefs on Sula, Røst, Træna and Fugløy are given. [ABSTRACT FROM AUTHOR]

Submarine canyons are structurally complex habitats known to support high densities and diversity of megafaunal organisms. This study describes deepwater corals and their habitats in The Gully, the largest submarine canyon in eastern North America, situated at the Canadian margin off Nova Scotia. Video recordings of the seabed were made along 49 transects, at depths between 110 and 544 m, using a tethered video camera system. The Gully has a high diversity of habitats with steep bedrock outcrops, high relief bottom with ledges of semi-consolidated mudstone, as well as level soft bottoms and areas with gravel. In total 95 megafaunal taxa were observed of which 16 species were corals. There was a strong, positive correlation between the total number of megafaunal taxa and number of coral species along transects, suggesting that coral diversity is a good indicator for overall megafaunal diversity. Corals were present in most parts of the canyon, and up to 11 species were observed along a single transect. The distribution patterns of corals were mainly related to distance along the axis from the canyon head and type of seabed substratum. The highest abundance of corals was found on the western side in the outer part of the canyon and is probably related to circulation patterns with a higher load of particulate matter in the out-fl owing water. Nephtheid soft corals, mainly Duva florida, were most frequent and were found within the whole depth range. Gorgonian corals were observed only deeper than 340 m. Except for Acanella arbuscula and Radicipes gracilis, which are anchored in mud, the gorgonians were mainly confined to areas with cobble and boulder and in a few cases to semiconsolidated mudstone. Multivariate analyses were applied to identify groups of transects and species, and to indicate which environmental factors control the distribution of corals and other megafauna in The Gully. [ABSTRACT FROM AUTHOR]

This study reports for the first time on the occurrences of deep-water coral species in the Spanish territorial waters of the Strait of Gibraltar. Based on an extensive dataset of 334 grab samples, 16 species of calcareous corals have been identified in water depths between 13–443 m. Scleractinian corals form the dominant benthic community between 140–330 m water depth. The corals appear on the seabed both as solitary individuals and as patches on small biological topographic build-ups. The most common coral species Lophelia pertusa and Madrepora oculata are associated with coarse-grained calcareous sediments and mound structures. In the shallowest part of the study area (<150 m) algae and bryozoans are dominant and only a few coral species are observed. This zonation and the occurrence of the azooxanthellate corals in the Strait of Gibraltar relates to light availability and perhaps also to the complex interaction between the outflow of Mediterranean water and surficial inflow of Atlantic water into the Mediterranean Sea. [ABSTRACT FROM AUTHOR]

Acesta excavata is the largest known bivalve associated with the Lophelia pertusa communities along the northeast Atlantic continental margin, but has also been found along steep cliffs, devoid of bathyal corals, and on more subdued topographies. During the Pleistocene, including the last glacial, A. excavata was widespread in the Mediterranean, but is in the Recent fauna known only from four Mediterranean sites. A new possible live-record from the Canyon du Var off Nice is presented. Radiocarbon dating (AMS 14C-method) on an A. excavata assemblage from the Strait of Sicily yielded a Late Pleistocene age of 39.9 ka. Biometric parameters indicate that Pleistocene Mediterranean shells achieved about the same maximum sizes as their Recent Atlantic counterparts, but individuals have been slightly smaller on average. The subspecies Acesta excavata sublaevis Nordsieck, based on a subfossil juvenile Mediterranean shell, is not considered a valid taxon. Mineralogical composition and ultrastructure of A. excavata have been analyzed using thin-sections, Feigel staining, x-ray diffractometry (XRD) and SEM-imaging. Its wide distribution, large size (15 cm) and simple shell architecture makes it a prime candidate for palaeoenvironmental studies in cold-water coral settings. [ABSTRACT FROM AUTHOR]

Deep-water corals are widespread in the North Atlantic. Colonial azooxanthellate scleractinians sustain ecosystems mostly in the bathyal zone down the slopes and oceanic banks off the Iberian Peninsula to as far north as the Scandinavian shelf off northern Norway. Estimates of the geological age of 37 deepwater corals exposed at the seabed from major reef areas in the North Atlantic were based on U/Th datings. In contrast to the purely Holocene ages of deep-water corals in Scandinavian waters, the Faroe area and the Rockall Trough, deep-water corals from lower latitudes like the seamounts off NW-Africa, the Mid-Atlantic Ridge and the western Mediterranean Sea seemed to have grown continuously over the last 50 ka. Overall, deep-water corals showed U/Th ages between 0.09 and 53.5 ka. [ABSTRACT FROM AUTHOR]

Modern and widespread deep-water coral ecosystems have become a major target of research during the last decades. So far, only a few fossil counterparts of such carbonate-secreting deep-water communities have been described. This scarcity might be a result of either, a possible miss-identification as a tropical deposit and/or the rare case of tectonic uplift and subsequent access to these deepwater deposits. The early Pleistocene St. Paul’s Bay Limestone on the island of Rhodes (Greece) represents one of the few known examples of the bathyal ‘white coral community’ dominated by Lophelia pertusa which are exposed on land. This occurrence relates to a convergent tectonic setting with large-scale uplifts in the vicinity of the European-African plate boundary that is responsible for the exposure of these early Pleistocene deep-water deposits. The geometry of the St. Paul’s Bay Limestone significantly differs from the mound-forming Lophelia occurrences as known, e.g., from the NE-Atlantic or the Florida Strait. Instead, it appears similar to the modern ‘white coral community’ of the western Mediterranean Sea that is usually associated with submarine cliffs. Much like the latter, the St. Paul’s Bay Limestone demonstrates that the growth and final deposition of the ‘white coral community’ was strongly influenced by the complex relief with steep submarine basement cliffs generated by horst-graben systems. These submarine cliffs not only provided the main habitat for the ‘white coral community’, they also explain recurrent instability and redeposition by debris falls along the submarine cliffs. Such a debris fall mechanism is strongly suggested by: (1) the steep slope angles (>30°), (2) the short transport distance (<20 m), (3) the wedge-like geometry, (4) the lack of grading, (5) the fabric complexity with incorporated fragments of hardgrounds, intraclasts and slightly consolidated sediment, (6) geopetal structures of various directions, thus indicating multiple resedimentation events, and (7) the variety of fragmentation and bioerosion. This resulted in the final deposition of the ‘white coral community’ (1) at the foot of submarine cliffs and (2) in neptunian dykes and, to a minor extent (3) in erosional depressions of the basement rock. In conclusion, the basic characters of the St. Paul’s Bay Limestone in terms of the initial facies, fabric and fauna largely match those described for lithoherms (Florida Strait). The enhanced complexity in terms of the final fabric and the wedge-like geometry appear due to multiple resedimentation events via debris falls along submarine cliffs. [ABSTRACT FROM AUTHOR]

In general, fossils of corals are rare within Eocene and Oligocene marine strata that accumulated in a deep-water, convergent-margin setting and are now exposed in western Oregon and Washington, northwestern USA. At some localities, however, specimens of a few coral taxa are relatively abundant and associated with authigenic limestone deposits. Recently, these highly-localized limestone deposits were recognized as having precipitated due to the microbial oxidation of methane at seeps, areas where hydrocarbon-rich fluids were vented to the sea floor because of the tectonic compression and faulting of underlying sediments. As at modern methane-seeps, the ancient seeps supported dense invertebrate communities, in most cases dominated by tube-dwelling worms and bivalve mollusks, but they can also include gastropods, polyplacophorans, sponges, and corals. A few methaneseep assemblages in Eocene and Oligocene rocks of the Lincoln Creek Formation include the corals Caryophyllia wynoocheensis Durham, and an undescribed Flabellum (Ulocyathus) species. A new species of Deltocyathus appears to be restricted to a single methane-seep site. The corals Stephanocyathus holcombensis Durham, and Flabellum hertleini Durham have been reported from what may be methane-seeps sites in the Lincoln Creek Formation near Holcomb, Washington, and associated with an unusual crinoid-rich bioherm in the Keasey Formation near Mist, Oregon. Other corals, Flabellum (Ulocyathus) n. sp., Archohelia? sp., Caryophyllia wynoocheensis, and Dendrophyllia hannibali Nomland, are reported from a Lincoln Creek Formation locality that includes methane-seep related assemblages near Knappton, Washington. Although widespread in the deep sea today, none of the genera found in the ancient seeps in Washington and Oregon have yet been reported from modern seeps, and corals have rarely been reported from pre-Tertiary methane-seep deposits. It is unlikely that any of these corals, like the bivalves and tubeworms found at methane-seeps, hosted and derived nutrients from endosymbiotic chemotrophic bacteria that were capable of metabolizing some of the reduced compounds in the seeping fluids. More likely, the corals probably were attracted to the greater amount of food at seeps relative to the surrounding deep sea, or to the attachment sites provided by hardgrounds of methane-derived carbonate deposits on the muddy seafloor. [ABSTRACT FROM AUTHOR]