The Mauritanian Slope (NE Atlantic) Has No Desert: <em>Swiftia phaeton</em> (Holaxonia: Plexauridae) Shaping Coral Gardens

Swiftia Duchassaing & Michelotti, 1864, is often found sparse in the NE Atlantic Ocean and Mediterranean Sea. When the cruise MSM 16/3 “PHAETON” filmed the upper bathyal off Mauritania in 2010, the first dense populations dominated by Swiftia were discovered in the NE Atlantic Ocean, co-occurring with the framework-forming scleractinians Desmophyllum pertusum (Linnaeus, 1758) and Madrepora oculata Linnaeus, 1758. Remotely operated vehicle (ROV) video annotation from two canyons and two coral mounds considered Swiftia phaeton Sampaio, Beuck & Freiwald, 2022 presence, size class and abundance as well as substrate and geomorphology of the seafloor. Coral gardens definition included abundance and size of the species. Dense and very dense mono- and multispecific coral gardens dominated by S. phaeton were mapped between 20°24′N and 17°54′N in 470–640 m depth. The resilience of these coral gardens off Mauritania is mainly linked to the presence of hard substrate available to settle and to the exposition of currents rich in food. Still, these ecosystems are located inside a hydrocarbon exploration area off Mauritania and where fisheries occur since the 1960s. Sedimentation plumes caused by both activities can travel and impact on settlement, development, and survival of these populations. Hence, these vulnerable “oases” should be protected

Environmental and biological controls on Na∕Ca ratios in scleractinian cold-water corals

Here we present a comprehensive attempt to correlate aragonitic Na∕Ca ratios from Desmophyllum pertusum (formerly known as Lophelia pertusa), Madrepora oculata and a caryophylliid cold-water coral (CWC) species with different seawater parameters such as temperature, salinity and pH. Living CWC specimens were collected from 16 different locations and analyzed for their Na∕Ca ratios using solution- based inductively coupled plasma-optical emission spectrometry (ICP-OES) measurements.The results reveal no apparent correlation with salinity (30.1–40.57 g  kg−1) but a significant inverse correlation with temperature (−0.31±0.04  mmolmol−1∘C−1). Other marine aragonitic organisms such as Mytilus edulis (inner aragonitic shell portion) and Porites sp. exhibit similar results highlighting the consistency of the calculated CWC regressions. Corresponding Na∕Mg ratios show a similar temperature sensitivity to Na∕Ca ratios, but the combination of two ratios appears to reduce the impact of vital effects and domain-dependent geochemical variation. The high degree of scatter and elemental heterogeneities between the different skeletal features in both Na∕Ca and Na∕Mg, however, limit the use of these ratios as a proxy and/or make a high number of samples necessary. Additionally, we explore two models to explain the observed temperature sensitivity of Na∕Ca ratios for an open and semi-enclosed calcifying space based on temperature-sensitive Na- and Ca-pumping enzymes and transport proteins that change the composition of the calcifying fluid and consequently the skeletal Na∕Ca ratio

REVIEW OF THE CENTRAL AND SOUTH ATLANTIC SHELF AND DEEP-SEA BENTHOS: SCIENCE, POLICY, AND MANAGEMENT

The Central and South Atlantic represents a vast ocean area and is home to a diverse range of ecosystems and species. Nevertheless, and similar to the rest of the global south, the area is comparatively understudied yet exposed to increasing levels of multisectoral pressures. To counteract this, the level of scientific exploration in the Central and South Atlantic has increased in recent years and will likely continue to do so within the context of the United Nations (UN) Decade of Ocean Science for Sustainable Development. Here, we compile the literature to investigate the distribution of previous scientific exploration of offshore (30 m+) ecosystems in the Central and South Atlantic, both within and beyond national jurisdiction, allowing us to synthesise overall patterns of biodiversity. Furthermore, through the lens of sustainable management, we have reviewed the existing anthropogenic activities and associated management measures relevant to the region. Through this exercise, we have identified key knowledge gaps and undersampled regions that represent priority areas for future research and commented on how these may be best incorporated into, or enhanced through, future management measures such as those in discussion at the UN Biodiversity Beyond National Jurisdiction negotiations. This review represents a comprehensive summary for scientists and managers alike looking to understand the key topographical, biological, and legislative features of the Central and South Atlantic.This paper is an output of the UN Ocean Decade endorsed Challenger 150 Programme (#57). Challenger 150 is supported by the Deep Ocean Stewardship Initiative (DOSI) and the Scientific Committee on Oceanic Research’s (SCOR) working group 159 (NSF Grant OCE-1840868) for which KLH is co-chair. AEHB, KLH, KAM, SBu, and KS are supported by the UKRI funded One Ocean Hub NE/S008950/1. TA is supported by the BiodivRestore ERA-NET Cofund (GA N°101003777) with the EU and the following funding organisations: FCT, RFCT, AEI, DFG, and ANR. TA also acknowledges financial support to CESAM by FCT/MCTES (UIDP/50017/2 020+UIDB/50017/2020+ LA/P/0094/2020) through national funds. NB is supported by the John Ellerman Foundation. AB is supported by the German Research Foundation. DH, CO, AFB, LA, SBr, and KS received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 818123 (iAtlantic); this output reflects only the author’s view and the European Union cannot be held responsible for any use that may be made of the information contained therein. DH, AF, JT, and CW were additionally supported through the Cluster of Excellence “The Ocean Floor – Earth’s Uncharted Interface” (EXC-2077 – 390741603 by Deutsche Forschungsgemeinschaft). CO also extends thanks to the HWK – Institute for Advanced Study, and PM to Dr. Alberto Martín, retired professor of Universidad Simón Bolívar in Caracas, Venezuela for facilitating references used in the Venezuela section.Peer reviewe

Charakterisierung gerüstbildender Kaltwasserkorallenökosysteme: Fallstudien auf makro- bis mikroskopischen Betrachtungsebenen

Deep-water corals have been known for more than two centuries; however, broad scientific interest in these hardly accessible ecosystems is relatively new and strongly increasing in the last years owing to application of advanced technologies. Like their shallow-water counterparts, frame-building deep-water corals play a fundamental role in the ecology of the oceans. However, cold-water coral ecosystems have been already economically discovered and exploited by e.g., the fishing industry and jewellery industry and thus are regionally threatened. Therefore, primarily it is important to map and characterise their global distribution to deduce marine protected areas, which allow securing the oceans ecosystem balances, to establish ecologically sustainable fishing practises and to protect its potential as a rich pool for studies gaining human’s benefit. Additionally, it is essential to carry out base studies, which give insights into the biodiversity, biocoenotic interactions, the ecosystem functioning and history. The presented work attempts a cold-water coral ecosystem characterisation by different key studies on a macro and micro-scale with main focus on the North Atlantic and Mediterranean Sea. Within this context, this thesis presents a set of methodologies embedded into different key studies, some of them having been applied for the first time to this scientific field. The individual key studies are grouped thematically: (1) Cold-water corals as habitat-forming substrate (Chapter 2) and (2) interactions between substrate and its colonisers on a micro-scale (Chapter 3). Chapter 2 comprises four key studies with the main focus set on a general characterisation of cold-water coral ecosystems, in particular: (a) their abiotically triggered distribution to trace their individual environmental requirements; (b) the role of cold-water corals as habitat-forming substrate to investigate biodiversity, biocoenotic interactions and long-term influences of abiotic factors; (c) their bio-induced degradation mechanisms to gain insights into the longevity and health of coral ecosystems. In Chapter 3 two key studies are established characterising interactions between substrate and colonisers on a micro-scale with special focus on host calcification as defence mechanism against colonisation. In general, the results from Chapter 2 indicate that currents have a strong influence on the appearance of cold-water coral ecosystems by shaping the mound structures, by causing the spatial distribution of corals and mechanically also coral framework transports, by transporting nutrients and therefore triggering the 'daily routine' of the biocoenosis and by affecting on destruction processes of cold-water coral frameworks. The key studies in Chapter 3 show that carbonate precipitation by the host is in most cases an effective defence mechanism against slowly growing epibionts (e.g., serpulids) but it constitutes a limited protection mechanism against boring organisms since carbonate for the latter group does not form any border. The individual key studies presented in Chapters 2 and 3 spotlight coral ecosystems from different perspectives and scales and can be considered as pieces of a huge mosaic that contribute synergistically to the understanding of these fascinating ecosystems. An upscaling of the key studies has been carried out in Chapter 4, and their individual potential is discussed in a larger content with special focus on the methodologies applied. The final outlook depicts the general potential of cold-water coral ecosystem analyses.Die Entdeckung der Tiefwasserkorallen liegt inzwischen mehr als zwei Jahrhunderte zurück; jedoch stießen diese schwer zugängigen Ökosysteme erst in den letzten Jahren auf breites, wissenschaftliches Interesse infolge der stark expandierenden technischen Erforschungsmöglichkeiten. Entsprechend tropischen Warmwasserkorallenökosystemen nehmen gerüstbildende Tiefwasserkorallenökosysteme eine wesentliche Rolle in der Ökologie der Ozeane ein. Allerdings stehen Kaltwasserkorallenökosysteme heutzutage unter einem stark kommerziellen Druck und werden vielfältig ausgebeutet, z.B. von der Fischindustrie und von der Juwelenindustrie, und sind somit regional gefährdet. Daher ist es primär wichtig, die globale Verbreitung dieser Ökosysteme zu erfassen und sie zu charakterisieren, um marine Schutzgebiete zu etablieren und ökologisch nachhaltige Fischfangverhalten zu implementieren. Diese Maßnahmen könnten das ökologische Gleichgewicht der Ozeane sicherstellen und ihr hohes Potenzial für zukünftige Studien zum Wohle der Menschheit konservieren. Darüber hinaus ist es wichtig, parallel Studien zur Ökosystemforschung durchzuführen, die Aufschluß über Biodiversität, biozönotischen Interaktionen, Funktionalität und ihre Entstehungsgeschichte geben. Die vorliegende Arbeit charakterisiert in verschiedenen Fallstudien Kaltwasserkorallenhabitate auf makro- und mikroskopischer Betrachtungsebene. Der Hauptfokus liegt dabei auf dem Nordatlantik und dem Mittelmeer. In diesem Kontext präsentiert diese Arbeit einige Methoden, die zum ersten Mal auf diesem Feld Anwendung finden. Die aus ihr resultierenden Fallstudien liegen thematisch gruppiert vor: (1) Kaltwasserkorallen als Lebensraum schaffende Substrate und (2) Interaktionen zwischen Substrat und Besiedlungsorganismen auf mikroskopischer Betrachtungsebene. Kapitel 2 beinhaltet vier Fallstudien und der Hauptfokus ist auf eine generelle Charakterisierung von Kaltwasserkorallenökosystemen gerichtet, im Besonderen auf: (a) ihre abiotisch kontrollierte Verbreitung, um ihre jeweiligen Umweltbedürfnisse auszumachen; (b) die Rolle von Kaltwasserkorallen als Lebensraum schaffendes Substrat, um die Biodiversität, biozönotischen Interaktionen und Langzeiteinflüsse von abiotischen Faktoren zu charakterisieren; (c) ihre biologischen Abbaumechanismen, um Einblicke in Lebensdauer und Gesundheit von Korallenökosystemen zu gewinnen. In Kapitel 3 liegen zwei Fallstudien vor, in denen Interaktionen zwischen Substrat und Besiedlern betrachtet werden. Der Schwerpunkt liegt dabei auf Wirtskalkabscheidung als Verteidigungsmechanismus gegen Besiedlung auf mikroskopischer Betrachtungsebene. Die Ergebnisse des Kapitels 2 zeigen, dass Strömungen auf verschiedenen Betrachtungsebenen einen starken Einfluss auf das heutige Erscheinungsbild der Korallenökosysteme nehmen, indem sie sowohl auf die Hügelmorphologie formend wirken, die Verbreitung von Korallen steuern, was hauptsächlich ihrer Nahrungsanlieferung und Sedimentationssteuerung zuzuschreiben ist, aber auch ihrer Transportkraft, sowie im kleinskaligeren Bereich die Morphologie und räumliche Orientierung der Korallenkelche beeinflussen und ihre Abbauprozesse maßgeblich steuern. Die Fallstudien in Kapitel 3 zeigen, dass eine Karbonatfällung seitens des Wirtes in den meisten Fällen einen effektiven Verteidigungsmechanismus gegen langsam wachsende Aufwuchsorganismen, wie Serpuliden bildet, jedoch einen limitierenden Schutz gegen Bohrorganismen darstellt, da Karbonatskelett für letztere Gruppe keine Grenze definiert. Die individuellen Fallstudien in Kapitel 2 und 3 beleuchten Korallenökosysteme aus verschiedenen Perspektiven und Betrachtungsebenen und können somit als Teile eines großen Mosaiks aufgefasst werden, die synergistisch zum Verständnis dieser faszinierenden Ökosysteme beitragen. Eine Hochskalierung der Fallstudien wurde in Kapitel 4 vorgenommen, in dem darüber hinaus auch ihre individuellen Potenziale in einem größeren Zusammenhang diskutiert sind und spezieller Fokus unter anderem auf die angewandten Methoden gelegt worden ist. Der abschließende Ausblick zeichnet das generelle Potenzial von Kaltwasserkorallenökosystemstudien auf

Where Topsent went wrong: Aka infesta a.k.a. Aka labyrinthica (Demospongiae: Phloeodictyidae) and implications for other Aka spp.

Early descriptions for species of Aka were poor in detail, and the only spicule type that occurs in this genus does not vary much between species, which led to taxonomic confusion. Moreover, the type specimens of five species of Aka are lost, causing considerable problems. Mediterranean specimens of Aka were identified as Aka labyrinthica (Hancock, 1849) by Topsent (1900), even though this species was originally described from the Indo-Pacific. All following publications on Mediterranean Aka accepted Topsent's decision. We assessed this problem with new samples from the Ionian Sea. Our material consisted of only one specimen of Aka, and we had to rely mainly on spicule characters for comparison with other species. We developed a system for species recognition solely based on spicular characters and biometry, involving a combination of the parameters oxea length, width, tip form and angle of curvature. This approach was surprisingly accurate. Forming ratios of the above parameters was less helpful, but can sometimes provide additional information. We identified our sample as Aka infesta (Johnson, 1899), and describe it as a minute-fistulate species with large, multicamerate erosion traces and stout, smooth oxeas. Our data further imply that A. labyrinthica sensu Hancock has not yet been found in the Mediterranean. Aka labyrinthica sensu Topsent is a collection of different species not including A. labyrinthica sensu Hancock

Bioerosion patterns in a deep-water Lophelia pertusa (Scleractinia) thicket (Propeller Mound, northern Porcupine Seabight)

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

A new species of squat lobster of the genus Munida (Galatheoidea, Munididae) from the Red Sea

Este artículo contiene 10 páginas, 5 figuras.During a deep-water expedition to the Red Sea in 2013, an unusual specimen of squat lobster belonging to the genus Munida was collected off Thuwal, Saudi Arabia, at a depth of 320 m. This specimen is unique in having the pterygostomial flap visible from the dorsal side, the feature linking it to two eastern Pacific species, M. bapensis Hendrickx, 2000 and M. macrobrachia Hendrickx, 2003. The new species (M. tuerkayi) is readily distinguished from the eastern Pacific species by having the gastric region with numerous instead of less numerous spines, by having sternite 7 with three distinct carinae on each side, and by having the antennular basal article with two distal spines subequal instead of different in size. Munida tuerkayi was found associated with live colonies of the scleractinian coral Eguchipsammia fistula (Alcock, 1902).LB received funds from EU-FP7 Projects CoralFISH (contract no. 213144), HERMIONE (contract no. 226354), and the Hessian initiative for the development of scientific and economic excellence (LOEWE) at the Biodiversity and Climate Research Centre (BiK-F), Frankfurt a. M., Germany.Peer reviewe

Munidopsis penescabra Pequegnat & Williams 1995

&lt;i&gt;Munidopsis penescabra&lt;/i&gt; Pequegnat &amp; Williams, 1995 &lt;p&gt;(Fig. 4 B)&lt;/p&gt; &lt;p&gt; &lt;i&gt;Munidopsis penescabra&lt;/i&gt; Pequegnat &amp; Williams 1995: 788, figs 2c&ndash;e, 3, 4b (western North Atlantic, north-western Gulf of Mexico, 543&ndash; 807 m.&mdash; Baba &lt;i&gt;et al.&lt;/i&gt; 2008: 154 (compilation).&lt;/p&gt; &lt;p&gt; &lt;b&gt;Material examined&lt;/b&gt;. Campeche Bank (Gulf of Mexico): SMF 49248, 2 males, 4.1&ndash;5.6 mm, 23&deg;50.121&rsquo;N, 87&deg;10.484&rsquo;W, 565 m, RV &lsquo; Maria S. Merian&rsquo; MSM 20/4 Station GeoB 163 08-1, BC, 22 March 2012, on muddy pteropod-foraminiferan ooze, associated with stalked crinoids, sponges, bryozoans, barnacles, brachiopods and few dead scleractinian fragments (mainly &lt;i&gt;Lophelia pertusa&lt;/i&gt; (Linnaeus, 1758)); SMF 49254, 2 males, 2.8&ndash;5.9 mm, 23&deg;49.731&rsquo;N, 87&deg;10.319&rsquo;W, 578 m, RV &lsquo; Maria S. Merian&rsquo; MSM 20/4 Station GeoB 163 09-1, BC, 22 March 2012, no sediment collected&mdash;associated with &lt;i&gt;Munidopsis tuerkayi&lt;/i&gt; n. sp., sponges and few dead scleractinian fragments (mainly &lt;i&gt;Lophelia pertusa&lt;/i&gt;).&lt;/p&gt; &lt;p&gt; &lt;b&gt;Colour in life.&lt;/b&gt; Carapace and abdomen pale brown; P1&ndash;4 whitish or pale brown. Cornea pale brown.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Remarks&lt;/b&gt;. The material examined agrees quite well with the original description. Pequegnat &amp; Williams (1995) compared this species with &lt;i&gt;M. scabra&lt;/i&gt; Faxon, 1893 and &lt;i&gt;M. tanneri&lt;/i&gt; Faxon, 1893, both from the eastern Pacific. &lt;i&gt;Munidopsis penescabra&lt;/i&gt; is also close to &lt;i&gt;M. acutispina&lt;/i&gt; Benedict, 1902, from the north-east Atlantic and Mediterranean Sea (Froglia &lt;i&gt;et al.&lt;/i&gt; 2002; Macpherson &amp; Segonzac 2005). The differences are in the following:&lt;/p&gt; &lt;p&gt; The dorsal surface of the carapace has numerous small scales each ending in a well-developed spine in &lt;i&gt;M. penescabra,&lt;/i&gt; whereas these scales are large each ending in a small spine in &lt;i&gt;M. acutispina&lt;/i&gt;.&lt;/p&gt; &lt;p&gt; The eyespine is much larger in &lt;i&gt;M. penescabra&lt;/i&gt; than in &lt;i&gt;M. acutispina&lt;/i&gt;.&lt;/p&gt; &lt;p&gt; The suborbital spine is well developed in &lt;i&gt;M. penescabra&lt;/i&gt;, whereas this spine is absent in &lt;i&gt;M. acustina&lt;/i&gt;.&lt;/p&gt; &lt;p&gt; The spines on P1&ndash;4 are stronger in &lt;i&gt;M. penescabra&lt;/i&gt; than in &lt;i&gt;M. acutispina&lt;/i&gt;.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Distribution&lt;/b&gt;. The species was only known from off Georgia and northwestern Gulf of Mexico, 543&ndash; 807 m. The present specimen is from the southeastern Gulf of Mexico, at 565&ndash; 578 m.&lt;/p&gt;Published as part of &lt;i&gt;Macpherson, Enrique, Beuck, Lydia &amp; Freiwald, Andrè, 2016, Some species of Munidopsis from the Gulf of Mexico, Florida Straits and Caribbean Sea (Decapoda: Munidopsidae), with the description of two new species, pp. 405-416 in Zootaxa 4137 (3)&lt;/i&gt; on page 409, DOI: 10.11646/zootaxa.4137.3.7, &lt;a href="http://zenodo.org/record/264193"&gt;http://zenodo.org/record/264193&lt;/a&gt