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The health status of cold-water coral reefs on the West African coast was investigated with the main objective of obtaining knowledge of the adaptive capacity of Lophelia pertusa to environmental stressors. Three coral sites were studied, in Northern Morocco, in the Morocco/Mauritania region (both in 2020) and, in the Ghana and Ivory coast region (visited in 2012, 2017, and 2019). Area cover of live colonies, explored through underwater videos, was used as an indicator of reef health and compared with the environmental variables: reef position, depth, water mass, temperature, dissolved oxygen concentration (DO), carbonate chemistry (pH, aragonite saturation (ΩAr), macronutrients and particles (visual). For a broader picture of the adaptations presented by Lophelia our results were compared with reefs in contrasting environments. Off Ghana and Mauritania healthy reefs (i.e., having areas with more than 20 % cover of live colonies) were found to reside at DO concentrations between 1.1 and 1.6 ml L−1, in corrosive waters (pH 7.7 and ΩAr 1.0) with high nutrient concentrations. By contrast, the reefs off the North of Morocco, sitting in well-oxygenated waters with oversaturated ΩAr, had no or few live colonies. Our findings together with data from other studies show that Lophelia has a wide tolerance to hypoxia and acidification, and that in relation to climate change increased temperature and silting could pose more serious threats. These findings highlight the importance of continued studies of Lophelia reefs in contrasting environmental conditions to better understand their adaptation potential to climate change-related stressors. [ABSTRACT FROM AUTHOR]

Cold-water corals of the Late Pleistocene (21,400-22,500 BP) are recorded from the sea-bottom of two inter-atoll channels (Kardiva Channel at 457-m depth and Malé Vaadhoo Channel at 443-m depth) of the eastern row of the Maldives archipelago. Coral assemblages are composed mainly by Lophelia pertusa and secondarily by Madrepora oculata and Enallopsammia rostrata. These cold-water coral patches are places where the benthic life, mainly sessile, is concentrated, which is clearly absent off-rubble patches. The main epibionts are tube-dwelling polychaetes (mainly Spirorbis and Serpula), bryozoans, siliceous sponges, barnacles, gorgonids, solitary corals, encrusting foraminifera, and microbial mats. The analysis of epibionts assemblages shows different biocoenoses between both studied sites as well as a dependency of the epibiont coverage with regard to the coral genus. Some living benthic organisms such as brachiopods, bivalves, gastropods, barnacles, and ophiuroids find refuge among coral branches. The common record of juvenile specimens of vagile organisms such as small ophiuroids, is probably related to the nursery function of the cold-water corals in spite they are fossils. Environmental requirements of Recent cold-water corals ( Lophelia, Madrepora and Enallopsammia) differ of conditions at both sampling sites with sensibly lower oxygenation degree and density of waters than needed for cold-water corals. Therefore, it is proposed that the present-day oxygen and density conditions are the factors which inhibit modern cold-water coral growth in the inter-atoll channels. [ABSTRACT FROM AUTHOR]

Background: In recent years, several types of molecular markers and new microscale skeletal characters have shown potential as powerful tools for phylogenetic reconstructions and higher-level taxonomy of scleractinian corals. Nonetheless, discrimination of closely related taxa is still highly controversial in scleractinian coral research. Here we used newly sequenced complete mitochondrial genomes and 30 microsatellites to define the genetic divergence between two closely related azooxanthellate taxa of the family Caryophylliidae: solitary Desmophyllum dianthus and colonial Lophelia pertusa. Results: In the mitochondrial control region, an astonishing 99.8 % of nucleotides between L. pertusa and D. dianthus were identical. Variability of the mitochondrial genomes of the two species is represented by only 12 non-synonymous out of 19 total nucleotide substitutions. Microsatellite sequence (37 loci) analysis of L. pertusa and D. dianthus showed genetic similarity is about 97 %. Our results also indicated that L. pertusa and D. dianthus show high skeletal plasticity in corallum shape and similarity in skeletal ontogeny, micromorphological (septal and wall granulations) and microstructural characters (arrangement of rapid accretion deposits, thickening deposits). Conclusions: Molecularly and morphologically, the solitary Desmophyllum and the dendroid Lophelia appear to be significantly more similar to each other than other unambiguous coral genera analysed to date. This consequently leads to ascribe both taxa under the generic name Desmophyllum (priority by date of publication). Findings of this study demonstrate that coloniality may not be a robust taxonomic character in scleractinian corals. [ABSTRACT FROM AUTHOR]

The distribution of nine cold-water corals in the cold temperate North Atlantic is described based on existing records. The species studied are Lophelia pertusa, Madrepora oculata, Paragorgia arborea, Primnoa resedaeformis, Paramuricea placomus, Acanella arbuscula, Isidella lofotensis, Radicipes gracilis and Acanthogorgia armata. The compiled number of records were 5,854, of which 4,875 were obtained from databases and 979 from publications. Distribution maps were produced and temperature, broad-scale topography and current patterns were considered to understand the distribution patterns and conditions at which the species thrive. Currents connecting shelves and slopes above 500 m can explain the wide spatial distribution of L. pertusa, P. arborea and P. resedaeformis. However, L. pertusa is scarce on the western side of the North Atlantic, P. arborea has only few records off Iceland and A. arbuscula and A. armata are not found on the Norwegian shelf. The differences in distribution patterns between species indicate that they are differently affected by the topographic barrier between the North Atlantic and the Nordic Seas. Present knowledge of dispersal ability of cold-water corals does not allow a firm causal explanation to the observed distribution patterns. These, however, are indicative of biogeographic provinces relevant to cold-water corals and their habitat requirements. [ABSTRACT FROM AUTHOR]

Polyp expansion state in Lophelia pertusa was studied in situ close to an oil rig during the drilling of a well (Statoil) off mid-Norway, in order to study possible effects on behaviour. The expansion state was monitored visually during the discharge of drill cuttings at one reef exposed to discharges and one not exposed. The reef situated down-current from the discharge point was monitored during 5 days and 15 h with a benthic lander equipped with a stills camera and current meter. This reef was exposed to drill cuttings 11 times during the monitoring. The total exposure time was 13 h 37 min. A remotely operated vehicle was used to provide additional images from both reefs for comparison. The proportion of polyps in different expansion states did not differ significantly between exposed corals and unexposed corals. Rather, changes in polyp behaviour were related to changes in current direction and velocity. A higher proportion of the polyps was expanded during periods with prevailing northeasterly currents compared to northwesterly. This could be related to quantity and type of food particles or the polyps' local position in the colony relative to current direction. There was also a clear difference in the degree of polyp expansion between polyps situated high up in the colony compared to low. This may be related to local environmental differences representing different hydrodynamic conditions. Whether or not there are effects of exposure to drill cuttings over a longer timescale than the observed 5 days and 15 h cannot be concluded from this study. [ABSTRACT FROM AUTHOR]

Surveys conducted at the complex Avilés Canyon System (southern Bay of Biscay) in order to identify vulnerable habitats and biological communities revealed the presence of noteworthy deep-water coral reefs in one of the tributaries of the system (La Gaviera Canyon). The aim of the present study is to determine why this deep-sea canyon provides suitable environmental conditions for corals to grow. This hanging canyon is characterized by an irregular U-shaped floor with two narrow differentiated flanks. Sand ripples and rocky outcrops structured in diverse W–E directed steps are observed on the canyon floor, suggesting intense hydrodynamic activity. Accordingly, high-frequency near-bottom current and thermal structure profiles showed that there occur strong shifts in currents/hydrography behaving as front-like features at each tidal cycle. These involve the sudden increase of along-axis velocities to over 50 cm/s and vertical velocities of over 5 cm/s in each tidal cycle associated with the passage of sharp thermal fronts and thermal inversions suggesting overturning. A year-long near-bottom current record showed events with near-bottom velocities well over 1 m/s lasting for several days. Three cold-water coral settings were distinguished: a dense coral reef located on stepped rocky bottoms of the eastern and western flanks, carbonate mounds (20–30 m high) located on the canyon floor, and a cluster of shallower water dead coral framework at the head sector of the canyon. Video and still images from a towed sled and ROV verified the presence of dropstones and rippled sand sheets surrounding the mounds and revealed changes in the coral population (alive or dead; total or patchy coverage) in coral reef and carbonate mound areas. The dominant species of the reef are Lophelia pertusa and Madrepora oculata , which considerably increase the habitat′s complexity and biodiversity in relation to other facies described in the canyon. The presence of living cold-water reefs is directly related to a high-energy environment at depths between 700 and 1200 m in the levels between the lower bound of Eastern North Atlantic Central Water (ENACW) and the core of Mediterranean Water (MW). Such level matches the water density range σ θ =27.35–27.65 kg m −3 which has been identified as limits for cold-water coral distribution in the North Atlantic. [ABSTRACT FROM AUTHOR]

This study describes the distribution, species composition and environmental characteristics of benthic habitats and biotopes from 38 stations in the Hardangerfjord, based on observations using high-definition video. Faunal composition was primarily related to substrate composition, distance from open ocean and depth (water masses) by using Detrended Correspondence Analysis. Six different biotopes were observed at depths between 100 and 400 m: (1)Lopheliareef, (2) sponge garden, (3) seapen communities, (4) soft bottom coral garden, (5) hard bottom coral garden and (6) cerianthid stands. ThreeLopheliareefs were observed between 140 and 230 m depth in the outer part of the fjord.Geodiaspp. and other large sponges were abundant on morainic bottom, on sills. Seapen communities occurred on muddy bottoms mainly between 250 and 350 m depth. The soft bottom coral garden comprised the gorgonianIsidella lofotensis, locally with densities up to 167 colonies/100 m2. Hard bottom coral gardens withParagorgia arboreaandParamuricea placomushad a much lower density with a maximum of 33 colonies/100 m2. Litter and lost fishing gear were observed on 49% of the locations.Lopheliaand sponges were covered with silt to a much higher degree than previously observed offshore. Whether this is caused by naturally higher particle flux in fjords or is due to an increased input from anthropogenic sources cannot be concluded from the present study. In general, anthropogenic activities have lead to increased particle flux in fjords and a demand for monitoring sensitive deep-water habitats to detect related trends of declining biodiversity. [ABSTRACT FROM AUTHOR]

Abstract: We report, for first time, the occurrence of cold-water coral mounds and large number of living Lophelia reefs along the Galicia Bank (Atlantic NW Iberian margin). Detection and mapping of living coral reefs and mounds have been carried out by means of multibeam bathymetry, backscatter images, ultra-high resolution and high-resolution multichannel seismic reflection data and sampling. In addition, profiling CTDs have been made to characterise environmental conditions as temperature, salinity and dissolved oxygen contents of the coral sites. Based on these dataset, two main provinces of cold-water coral mounds and reefs have been identified in the Galicia Bank at water depths between 620 and 1125m. The Breogham Mound Province along the western flank of the Galicia Bank shows a sequence of well-developed mounds composed of: (1) Stepped semi-buried elongated mounds, the tallest mounds with heights up 70m and widths of 450m lined up in along-slope trending ridges and intercalated with upslope migrating sediment drifts at water depths from 1125 to 826m; (2) Single and composite seabed mounds show heights of 10–12m and average widths of 100m at 825 and 780m water depths and (3) Lophelia reefs forming mini-mounds 2–4m high and 80–100m width growing on a flat erosional surface at the summit of the bank at 780–750m water depths. Otherwise, the Castelao Mound Province at the eastern flank of the bank is mainly constituted by cluster of mini-mounds hosting living Lophelia pertusa and Madrepora oculata reefs. These living reefs are detected based on ultra-high resolutions parametric echosounders as mini-mounds with an acoustically transparent interior. Otherwise, semi-buried and exposed mounds are mapped with a combination of multibeam and backscatter images identified by their high strength values and seabed expression. We conclude that the initiation, growth and distribution of cold-water coral mounds on the Galicia Bank have been controlled by the following environmental forcing factors: (i) water masses with a potential density resulted of the turbulent boundary between the Mediterranean Outflow and the intermediate Atlantic water masses which allowed the transport of coral larvae along the NE Atlantic margins (ii) the formation of a hard substrate, possibly related to subsurface fluid flow, necessary for the initial settle of coral larvae and (iii) the turbulences created by the Mediterranean flow impinging the topography of the bank creating suitable currents that favour intrusion of the nutrient afflux from the Atlantic mass waters to deep waters allowing to coral colonies to growth. [Copyright &y& Elsevier]

CT scanning and descriptions of sedimentary sequences have been conducted to describe the internal structure and define the evolutionary sequence of events leading to the build-up of cold-water coral reef constructed by the azooxanthellate scleractinian Lophelia pertusa. Two vibrocores containing coral clasts and associated fauna embedded in a matrix of marine sediment were taken at the Mingulay Reef Complex, an inshore (~120–190 m water depth) L. pertusa reef off western Scotland. The cores were scanned using computed x-ray tomography (CT scan) with the aim of (1) reconstructing and quantifying the relative abundance and preservation of coral fragments in the cores, (2) identifying distinct reef facies, and hence (3) providing data that could lead to a conceptual model of reef growth. U-series dates were obtained on L. pertusa clasts from the two sediment cores to provide a temporal framework of the reef build-up. After exploring a range of methods for processing CT scans, three simple parameters were used to classify different strata within the cores: the overall density of the cores, the number of fossil clasts, and the sum of the area of clasts detected by the CT scan. These parameters were validated by comparing with density measurements from a multi-sensor core logger (MSCL) and physical dissection and analysis of fossils in the cores. From the CT scan analyses, three distinct reef facies were evident: Coral-Rich, Sediment-Rich and Shelly-Coral Hash Layers. The succession and rapid cycle of reef framework-forming L. pertusa development, disturbance and recovery allow us to provide a model of cold-water coral reef build-up including shifts in biodiversity, physical/chemical/biological processes and the sedimentary regime. [ABSTRACT FROM AUTHOR]

High-resolution topographic mapping of Norwegian deep-water Lophelia coral reefs and their immediate surrounding seafloor has disclosed striking associations with small (<5 m diameter) 'unit' pockmarks. A total of four study areas with Lophelia reefs and unit pockmarks are here described and discussed. At the large Fauna reef, which spans 500 m in length and 100 m in width (25 m in height), there is a field of 184 unit pockmarks occurring on its suspected upstream side. Three other, intermediate-sized Morvin reefs are associated with small fields of unit pockmarks situated upstream of live Lophelia colonies. For two of the latter locations, published data exist for geochemical and microbial analyses of sediment and water samples. Results indicate that these unit pockmarks are sources of light dissolved hydrocarbons for the local water mass, together with nutrient-rich pore waters. It is suggested that the 'fertilized' seawater flows with the prevailing bottom current and feeds directly into the live portion of the Lophelia reefs. With an estimated growth rate of ~1 cm per year for the Morvin Lophelia corals, it would take between 1,000 and 2,000 years for the reefs to colonize the closest unit pockmarks, currently occurring 10-20 m from their leading (live) edges. [ABSTRACT FROM AUTHOR]

Abstract: We present an initial genomic analysis of the non-symbiotic scleractinian coral Lophelia pertusa, the dominant cold-water reef-building coral species in the North Atlantic Ocean. A significant fraction of the deep sequencing reads was of mitochondrial and microbial origins. SOLiD deep sequencing reads from fragment library experiments of total DNA and PCR amplified mitogenome generated about 21,000 times and 136,000 times coverage, respectively, of the 16,150bp mitogenome. Five polymorphic sites that include two non-synonymous sites in the NADH dehydrogenase subunit 5 genes were detected in both experiments. This observation is surprising since anthozoans in general exhibit very low mtDNA sequence variation at intraspecific level compared to nuclear sequences. More than fifty bacterial species associated with the coral isolate were also sequence detected, representing at least ten complete genomes. Most reads, however, were predicted to originate from the Lophelia nuclear genome. [Copyright &y& Elsevier]

Abstract: The cold-water coral Lophelia pertusa provides important habitat to many deep-sea fishes and invertebrates. Studies of the microbial taxa associated with L. pertusa thus far have focused on bacteria, neglecting the microeukaryotic members. This is the first study to culture fungi from living L. pertusa and to investigate carbon source utilization by the fungal associates. Twenty-seven fungal isolates from seven families, including both filamentous and yeast morphotypes, were cultured from healthy L. pertusa colonies collected from the northern Gulf of Mexico, the West Florida Slope, and the western Atlantic Ocean off the Florida coast. Isolates from different sites were phylogenetically closely related, indicating these genera are widely distributed in association with L. pertusa. Biolog™ Filamentous Fungi microtiter plates were employed to determine the functional capacity of a subset of isolates to grow on varied carbon sources. While four of the isolates exhibited no growth on any provided carbon source, the rest (n=10) grew on 8.3–66.7% of carbon sources available. Carbohydrates, carboxylic acids, and amino acids were the most commonly metabolized carbon sources, with overlap between the carbon sources used and amino acids found in L. pertusa mucus. This study represents the first attempt to characterize a microeukaryotic group associated with L. pertusa. However, the functional role of fungi within the coral holobiont remains unclear. [Copyright &y& Elsevier]

Abstract: Holocene Madrepora-Lophelia subfossil frames recovered at ca. 690m from deep-water coral grounds south of Malta (Strait of Sicily, Central Mediterranean Sea) were found to entrap shells of cnidarian predatory gastropods such as Babelomurex sentix, “Coralliophila”squamosa (morphotype ruderatus) and architectonicids. This finding documents the capability of deep-water coral reefs to serve as taphonomic traps eventually promoting the preservation of rare components of their original biota. [Copyright &y& Elsevier]

Abstract: In 1948, Le Danois reported for the first time the occurrence of living cold-water coral reefs, the so-called “massifs coralliens”, along the European Atlantic continental margin. In 2008, a cruise with R/V Belgica was set out to re-investigate these cold-water corals in the Penmarc''h and Guilvinec Canyons along the Gascogne margin of the Bay of Biscay. During this cruise, an area of 560km2 was studied using multibeam swath bathymetry, CTD casts, ROV observations and USBL-guided boxcoring. Based on the multibeam data and the ROV video imagery, two different cold-water coral reef settings were distinguished. In water depths ranging from 260 to 350m, mini mounds up to 5m high, covered by dead cold-water coral rubble, were observed. In between these mounds, soft sediment with a patchy distribution of gravel was recognised. The second setting (350–950m) features hard substrates with cracks, spurs, cliffs and overhangs. In water depths of 700 to 950m, both living and dead cold-water corals occur. Occasionally, they form dense coral patches with a diameter of about 10–60m, characterised by mostly stacked dead coral rubble and a few living specimens. U/Th datings indicate a shift in cold-water coral growth after the Late Glacial Maximum (about 11.5ka BP) from shallow to deep-water settings. The living cold-water corals from the deeper area occur in a water density (sigma–theta) of 27.35–27.55kgm−3, suggested to be a prerequisite for the growth and distribution of cold-water coral reefs along the northern Atlantic margin. In contrast, the dead cold-water coral fragments in the shallow area occur in a density range of 27.15–27.20kgm−3 which is slightly outside the density range where living cold-water corals normally occur. The presented data suggest that this prerequisite is also valid for coral growth in the deeper canyons (>350m) in the Bay of Biscay. [Copyright &y& Elsevier]

Abstract: Cold-water corals are widely distributed along the Atlantic continental margin with varying growth patterns in relation to their specific environment. Here, we investigate the long-term development of cold-water corals that once thrived on a low-latitude (17°40′N) cold-water coral mound in the Banda Mound Province off Mauritania during the last glacial–interglacial cycle. U/Th dates obtained from 20 specimens of the cold-water coral Lophelia pertusa, revealed three distinct periods of coral growth during the last glacial at 65 to 57kyrBP, 45 to 32kyrBP and 14kyrBP, thus comprising the cool periods of Marine Isotopic Stages (MIS) 2–4. These coral growth periods occur during periods of increased productivity in the region, emphasizing that productivity seems to be the major steering factor for coral growth off Mauritania, which is one of the major upwelling regions in the world. This pattern differs from the well studied coral mounds off Ireland, where the current regime predominantly influences the prosperity of the cold-water corals. Moreover, coral growth off Ireland takes place during rather warm interglacial and interstadial periods, whereas off Mauritania coral growth is restricted to glacial and stadial periods. However, the on-mound sedimentation patterns off Mauritania largely resemble the observations reported from the Irish mounds. The bulk of the preserved sediments derives from periods of coral growth, whereas during periods without corals hardly any net sedimentation or mound growth took place. [Copyright &y& Elsevier]

Authigenic gypsum was found in a gravity core, retrieved from the top of Mound Perseverance, a giant cold-water coral mound in the Porcupine Basin, off Ireland. The occurrence of gypsum in such an environment is intriguing, because gypsum, a classic evaporitic mineral, is undersaturated with respect to sea water. Sedimentological, petrographic and isotopic evidence point to diagenetic formation of the gypsum, tied to oxidation of sedimentary sulphide minerals (i.e. pyrite). This oxidation is attributed to a phase of increased bottom currents which caused erosion and enhanced inflow of oxidizing fluids into the mound sediments. The oxidation of pyrite produced acidity, causing carbonate dissolution and subsequently leading to pore-water oversaturation with respect to gypsum and dolomite. Calculations based on the isotopic compositions of gypsum and pyrite reveal that between 21·6% and 28·6% of the sulphate incorporated into the gypsum derived from pyrite oxidation. The dissolution of carbonate increased the porosity in the affected sediment layer but promoted lithification of the sediments at the sediment-water interface. Thus, authigenic gypsum can serve as a signature for diagenetic oxidation events in carbonate-rich sediments. These observations demonstrate that fluid flow, steered by environmental factors, has an important effect on the diagenesis of coral mounds. [ABSTRACT FROM AUTHOR]

Abstract: This study focuses on the carbonate biodegradation processes of deep-water scleractinians from off Apulia at Santa Maria di Leuca (SML) in the Ionian Sea, including living colonies of Lophelia pertusa, Madrepora oculata and Desmophyllum dianthus. The corallites were grouped into three zones: the live zone, edge zone and dead zone. In total, 13 trace types were encountered and are attributed to borings of sponges (3), fungi (6), foraminifers (2), bacteria (1) and annelids (1). Their relative spatial appearance within the host skeletons led to the distinction between six succession stages of bioerosion. The first endobiontic traces are exclusively produced by bacteria and fungi and are already present in the edge zone, which could be attributed to their fast growth rates and/or temporal exposure of the bare skeleton to the water column. In D. dianthus the entire ichnospecies assemblage has been documented within the first 1.9cm below the live zone and represents the most condensed bioerosion succession amongst the coral species studied. The strongest degradation of corallites at SML is made by boring sponges, which can excavate 70% or more of the skeleton. The finding of a unilateral condensed succession of bioerosion stages may be linked to prevailing unidirectional strong currents. A comparison of the present ichnocoenosis with bioerosion studies from the Eastern Atlantic evidences a reduced ichnodiversity in Ionian Sea bathyal corals. [Copyright &y& Elsevier]

Abstract: Two sites (MS04 and MS06) from the Santa Maria di Leuca (SML) Coral Province were analyzed by a video and acoustic survey during the National Italian Project Apulian Plateau Bank Ecosystem Study (APLABES). Site MS04 (Atlantis Mound) is characterized by a sub-conical mound, 500m wide and 25m high, located at a water depth of about 650m. Site MS06 (Yellow Chain) comprises several elongated reliefs (NNW–SSE-oriented), up to 25m high and 500m in maximum lateral extent, located at a depth of between 490 and 540m. At both sites, two main mesohabitats (mound and intermound) containing several coral-bearing and -barren macrohabitats were observed in recorded videos and detected in side-scan sonographs. The coral-rich macrohabitats, characterized by densely packed colonies of the scleractinians Madrepora oculata and, secondarily, Lophelia pertusa (M/L), are typically restricted to the mound areas. The mud-dominated ones, almost devoid of M/L colonies, are more common within the intermound mesohabitat. However, on the most extensive mounds, both macrohabitat typologies exist. They are heterogeneously distributed on the mound surface, often showing a clear differentiation along two opposite flanks of the same topographic feature. M/L-rich macrohabitats are preferentially located on top and along the mound northeastern flank, showing a typical step-like distribution, probably reflecting the arrangement of hard substrate outcrops. Along this flank, fan-shaped Madrepora colonies and sponges are often oriented NNW–SSE, implying, together with other evidence, a primary southwestern current flow. The hard-bottom macrohabitats of the southwestern mound flank are generally restricted to sparse exposed, subvertical to overhanging scarps as well as to heterometric boulders located at the scarp base. Their fauna is mainly characterized by small-sized organisms (such as sponges and solitary scleractinians) although m-sized boulders may locally host very large antipatharian colonies (Leiopathes glaberrima). The heterogeneous distribution of the observed benthic macrohabitats seems to be strictly related to the local topography, the main current flow (and consequently larvae/food supply per unit of time), and the substrate typology (hard- vs. soft-bottom). [Copyright &y& Elsevier]

Abstract: The Santa Maria di Leuca (SML) coral banks represent a rare example of living Lophelia-Madrepora-bearing coral mounds in the Mediterranean Sea. They are located between 350 and 1100m in depth, in the northern Ionian Sea (eastern-central Mediterranean). Using a multi-beam echo sounder, side-scan sonar, high-resolution seismics and underwater video, the zones were identified for the sampling demersal fauna without damaging the coral colonies. During September–October 2005 experimental samplings were carried out with longlines and trawl nets inside the coral habitat and outside, where fishery exploitation occurs. No significant differences were shown between the abundance of fish recorded using longlines in the coral and non-coral habitat even though some selachians and teleosts were more abundant in the former than in the latter. Large specimens of rockfish (Helicolenus dactylopterus) and blackspot seabream (Pagellus bogaraveo) were commonly caught using longlines in the coral habitat. Data from trawling revealed refuge effects in the coral habitat and fishing effects outside. Significant differences were detected between the recorded abundances in the two study areas. Greater densities and biomasses were obtained inside the coral area, and fish size spectra and size distributions indicate a greater abundance of large fish inside the coral habitat. The SML coral habitat is a spawning area for H. dactylopterus. The remarkable density of the young-of-the-year of the deep-water shark Etmopterus spinax as well as of Merluccius merluccius, Micromesistius poutassou, Phycis blennoides and H. dactylopterus, indicates that the coral habitat also acts as nursery area for these demersal species, which are exploited outside. Considering the evidence of the negative impact of bottom trawling and, to a lesser extent, of longlining, the coral banks can provide a refuge for the conservation of unique species and habitats as well as in providing benefit to adjacent fisheries through the spill-over effect both of eggs, larvae, juveniles and adults. [Copyright &y& Elsevier]

Abstract: Shallow sediment lithology and stratigraphy were investigated at selected areas off Santa Maria di Leuca (SML) on the Apulian margin between 350 and 1200m water depth, in order to define the sea-bottom character on which coral mounds have developed. According to existing geophysical data and in-situ observations, deep coral growth in the SML area creates patches of colonies typically settled on hard substrates on the upper flanks and/or near the top of mound-like structures and elongated ridges. The sedimentary stratigraphy is strongly influenced by the local topography, which is modeled by tectonic and geomorphological forcing: large-scale erosional features, slope failure and sediment mass accumulation are evident from seismic investigations. Additionally, sites of preferential sediment accumulation due to the action of bottom currents are identified. As a result, a complex sedimentary pattern characterizes this part of the Apulian margin, with strong lateral variability in sediment type and age. Although hemipelagic silty clay constitutes the main lithology, there are sites characterized by periodic accumulation of silt and fine sand and local re-deposition of coarse biogenic sand from the surrounding areas and from shallower depths. Excluding one site, where mid-Pleistocene sediments are brought very close to the bottom-surface due to wide-scale erosion, all collected sediments are late Pleistocene to Holocene in age and fall biostratigraphically within the Emiliania huxleyi acme nannofossil zone. Reworking, detected through nannofossil analysis, is common in most cores, excluding the ones taken from topographic highs, and is variable in extent from site to site and within the sediment column; it includes Cretaceous to Early Pleistocene species, suggesting provenance from extended successions or various stratigraphic levels, outcropping on the submerged Apulian margin or in adjacent land sections. Reworking is often associated with a high content of lithogenic particles and an increase in the coarser (silt) fraction. Coral debris was collected at many stations, both at the sediment surface and within the stratigraphic sequence, with varying abundance in relation to proximity to the coral colonies. Radiometric dating and micropaleontological analyses at some sites allow us to propose a sequence of coral colonization phases. [Copyright &y& Elsevier]

Abstract: During the past decade, knowledge about the ecology and the environment of giant carbonate mounds has been growing continuously. However, still little is known about their growth dynamics. Three gravity cores from Galway Mound, Belgica Mound Province in the Porcupine Seabight off Ireland, were investigated for their sedimentological, geophysical and geochemical properties to get insight into the long-term development of this cold-water coral covered carbonate mound. These data were supplemented by radiometric age determinations on planktonic foraminifera and coral skeletons. The records from three different settings on Galway Mound reveal a coherent growth history that in general is similar to what is known from other carbonate mounds at the Irish margin. However, whereas other cores are often disturbed by numerous and not correlateable hiatuses, Galway Mound, in contrast, appears to be characterised by only one major hiatus representing a time gap of ~250 kyr. Several mechanisms are discussed in this study as possible causes for the observed stratigraphic record at Galway Mound. The most likely explanation is that the hiatus has its origin in a major mass wasting event on an instable, possibly glacial, unit that could have acted as a slip plane. The overall Late Quaternary growth history of Galway Mound fits well into existing cyclical mound development models, pointing to Galway Mound being an ‘actively growing’ mound (“coral bank stage”) at present. [Copyright &y& Elsevier]

Sr isotope stratigraphy provides a new age model for the first complete section drilled through a deep-water coral mound. The 155-m-long section from Challenger Mound in the Porcupine Seabight, southwest of Ireland, is on Miocene siliciclastics and consists entirely of sediments bearing well-preserved cold-water coral Lophelia pertusa. The 87Sr/86Sr values of 28 coral specimens from the mound show an upward-increasing trend, correspond to ages from 2.6 to 0.5 Ma, and identify a significant hiatus from ca. 1.7 to 1.0 Ma at 23.6 m below seafloor. The age of the basal mound sediments coincides with the intensification of Northern Hemisphere glaciations that set up the modern stratification of the northeast Atlantic and enabled coral growth. Mound growth persisted throughout glacial-interglacial fluctuations, reached a maximum rate (24 cm/k.y.) ca. 2.0 Ma, and ceased at 1.7 Ma. Unlike other buried mounds in Porcupine Seabight, Challenger Mound was only partly covered during its growth interruption, and growth restarted ca. 1.0 Ma. [ABSTRACT FROM AUTHOR]

Abstract: Deep-sea or cold-water corals form substantial habitat along many continental slopes, including the southeastern United States (SEUS). Despite increasing research on deep coral systems and growing appreciation of their importance to fishes, quantitative data on fish communities occupying these ecosystems are relatively lacking. Our overall goals were to document the fish species and their relative abundances and to describe the degree of general habitat specificity of the fishes on and around deep coral habitats on the SEUS slope. From 2000 to 2006, we used the Johnson-Sea-Link (JSL) submersible (65 dives, 366–783m), supplemented with otter trawls (33 tows, 365–910m) to document fishes and habitats from off North Carolina to east-central Florida. Eight areas with high concentrations of deep-sea corals were surveyed repeatedly. Three general habitat types (prime reef, transition reef, and off reef) were defined to determine large-scale habitat use patterns. Throughout the area, at least 99 fish species were identified, many (19%) of which yielded new distributional data. Most species observed with the JSL were on prime reef (n=50) and transition reef (n=42) habitats, but the off reef habitat supported a well developed, but different fauna (n=25 species). Prime reef was characterized by Laemonema melanurum (21% of total), Nezumia sclerorhynchus (17% of total), Beryx decadactylus (14% of total), and Helicolenus dactylopterus (10% of total). The off reef areas were dominated by Fenestraja plutonia (19% of total), Laemonema barbatulum (18% of total), Myxine glutinosa (8% of total), and Chlorophthalmus agassizi (7% of total). Transition habitat exhibited a mixture of species that were also found on either prime reef or off reef habitats. Nezumia sclerorhynchus was the most abundant (25% of total) transition habitat species, followed by L. barbatulum (16% of total) and L. melanurum (14% of total). Several species (e.g., Anthias woodsi, B. decadactylus, Conger oceanicus, and Dysommina rugosa) demonstrated specificity to deep-reef habitats, while others (e.g., C. agassizi, Benthobatis marcida, F. plutonia, and Phycis chesteri) were always more common away from reefs. In addition to new distributional data, we provide behavioral and biological observations for dominant species. [Copyright &y& Elsevier]

The azooxanthellate scleractinian coral Lophelia pertusa has a near-cosmopolitan distribution, with a main depth distribution between 200 and 1000 m. In the northeast Atlantic it is the main framework-building species, forming deep-sea reefs in the bathyal zone on the continental margin, offshore banks and in Scandinavian fjords. Recent studies have shown that deep-sea reefs are associated with a highly diverse fauna. Such deep-sea communities are subject to increasing impact from deep-water fisheries, against a background of poor knowledge concerning these ecosystems, including the biology and population structure of L. pertusa. To resolve the population structure and to assess the dispersal potential of this deep-sea coral, specific microsatellites markers and ribosomal internal transcribed spacer (ITS) sequences ITS1 and ITS2 were used to investigate 10 different sampling sites, distributed along the European margin and in Scandinavian fjords. Both microsatellite and gene sequence data showed that L. pertusa should not be considered as one panmictic population in the northeast Atlantic but instead forms distinct, offshore and fjord populations. Results also suggest that, if some gene flow is occurring along the continental slope, the recruitment of sexually produced larvae is likely to be strongly local. The microsatellites showed significant levels of inbreeding and revealed that the level of genetic diversity and the contribution of asexual reproduction to the maintenance of the subpopulations were highly variable from site to site. These results are of major importance in the generation of a sustainable management strategy for these diversity-rich deep-sea ecosystems. [ABSTRACT FROM AUTHOR]

Lophelia pertusa and Madrepora oculata are azooxanthellate corals with nearly cosmopolitan distributions. They form cold-water reefs in the upper bathyal zone on continental margins and offshore banks [A.D. Rogers, Int. Rev. Hydrobiol. 84 (1999) 315]. Lophelia is classified in the family Caryophylliidae and Madrepora in the family Oculinidae, both on the basis of skeletal morphology. Recent molecular studies of the scleractinians have given a new insight into the evolutionary history of this group. This study was aimed at clarifying the phylogenetic relationships of Lophelia and Madrepora, through the analysis of partial sequences of the mitochondrial 16S rDNA. Sequences were obtained for samples of L. pertusa collected in the northeast Atlantic and off Brazil, M. oculata, four other deep-sea and eight tropical coral species from the Re´union island in the Indian Ocean. The sequences were aligned with 69 homologous sequences of Scleractinia. Maximum parsimony and Bayesian analyses support previously published molecular topologies. The two specimens of L. pertusa grouped with two caryophylliids, confirming the existing classification of the species, but the large genetic distance between the two Lophelia samples suggests that these populations are genetically isolated from one another. M. oculata did not cluster with oculinids, but formed a monotypic clade lying between the families Pocilloporidae and Caryophyliidae. Phylogenetic analysis also suggested cryptic speciation within the tropical taxa Pocillopora meandriana and possibly Acropora humilis. [Copyright &y& Elsevier]

A correction to the article "Merging scleractinian genera: the overwhelming genetic similarity between solitary Desmophyllum and colonial Lophelia," by A. M. Addamo and others, that was published in a 2016 issue is presented.