Andre Freiwald

Senckenberg am Meer, Wilhelmshaven · Marine Research

Sensitivity of reef-building corals to environmental factors has far-reaching ecosystem implications, especially in the limited number of cold-water coral (CWC) species that form reefs in the deep sea. Understanding CWC responses to large-scale oceanographic variation in their natural habitat can elucidate their sensitivity to global anthropogenic...

Gaidropsarus mauritanicus sp. nov. is described from one specimen collected using a grab sample from the Tanoûdêrt Canyon (ca. 20° N) off Mauritania at a depth of 595 m. The new species was further observed during eight remotely operated vehicle (ROV) dives along the Mauritanian slope southwards down to the Tiguent Coral Mound Complex (~17° N) in a...

Cold-water corals (CWC) in Norwegian waters have been known for more than two centuries, but direct studies of CWC reefs were first enabled with the introduction of new ROV (Remotely Operated Vehicle) technology in the 1980s. This provided new knowledge about reef ecology and how fisheries have impacted these fragile habitats. In this chapter we pr...

The discoveries of large reefs within cold-water coral mound provinces revealed that the West African margin is a coral hotspot area in the Atlantic Ocean. The most striking observation is that cold-water corals thrive in extensive oxygen minimum zones under extreme conditions. This points to a wide tolerance of cold-water corals in these regions t...

Deep-sea explorations performed over the last two decades have shown evidence of abundant living cold-water coral communities in the Mediterranean Sea. Many submarine canyons, escarpments, seamounts, and outer continental shelf and slope areas support communities dominated by scleractinian cold-water corals or coral gardens composed of a diverse fa...

Cold-water corals (CWC) form reef structures in continental margin and seamount settings at tropical, temperate, and even some polar latitudes. This global distribution makes them more widespread than shallow-water reefs, while their role in these regions is no less important than the influence that shallow-water coral reefs have on shallow, tropic...

This study investigates the molluscan fauna of the South Azorean Seamount Chain (SASC), which comprises several seamounts culminating in 300–1600 m depth, separated by distances less than 200 km. Material was collected mainly by dredging and comprises mostly empty shells. A total of over 111,000 shells representing at least 439 species (409 identif...

Didogobius lanceolatus sp. nov. is described from a single specimen collected from the southern Banc d’Arguin, Mauritania. The species differs from all currently described congeners, as well as from all species of the closely related species of the genera Chromogobius and Gammogobius, by the combination of the following characters: (1) lanceolate c...

Cold-water coral (CWC) reefs of the Angolan margin (SE Atlantic) are dominated by Desmophyllum pertusum and support a diverse community of associated fauna, despite hypoxic conditions. In this study, we use carbon and nitrogen stable isotope analyses (δ13C and δ15N) to decipher the trophic network of this relatively unknown CWC province. Although f...

Various reviews of families in Mollusca have indicated a large diversity and a high degree of endemicity on the Azorean seamounts. In this study, bathyal species in the gastropod family Fissurellidae have been investigated using material collected during the M151 cruise conducted by R/V Meteor in 2018 to seamounts south of the Azores. Additional re...

This study documents foraminiferal faunas from the Mauritanian upper slope and shelf and analyses their association with cold-water coral habitats (=CWCH). It is based on the analysis of foraminiferal tests in 28 sediment samples of the >250 µm fraction only. One hundred and fifty seven benthic species are recorded, described and one hundred and fi...

The three-dimensional (3D) structure of habitat-forming corals has profound impacts on reef ecosystem processes. Elucidating coral structural responses to the environment is therefore crucial to understand changes in these ecosystems. However, little is known of how environmental factors shape coral structure in deep and dark waters, where cold-wat...

This study is part of a broader inventory of bathyal molluscs from the Azores and South Azorean Seamount Chain. Herein a review was completed on taxa in the families Cerithiopsidae and Newtoniellidae, mostly represented in our material by empty shells. Twenty species are recorded, of which only five have a planktotrophic larval development. Six new...

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 Desmophyll...

A new species of pontogeneiid amphipod, Dautzenbergia concavipalma sp. nov., is described from cold-water corals off Angola. This is only the second observation of this genus in the South Atlantic. Important morphological characters in combination, which define the new species from its congeners, occur especially in the shape and size of gnathopod...

The diversity of molluscs living on the summits and bathyal slopes of the seamounts south of the Azores has been investigated since the late 19th century. Particularly the results gathered from the cruises made by the research vessels Hirondelle and Princesse Alice showed a high biodiversity and a high degree of endemism. A second large step change...

A new species in the family Anatomidae J. H. McLean, 1989 (Gastropoda) is proposed: Anatoma occidentalis n. sp., found off Mauritania and Angola. Empty shells of the new species were found in sediment samples collected in habitats associated with deep-water corals from an upper bathyal depth range.

Three species of the genus Swiftia are known for the NE Atlantic Ocean and Mediterranean Sea. Remotely operated vehicle (ROV) surveys and sampling on board RV Maria S. Merian during cruise MSM 16/3 'PHAETON' in 2010 provided footage and specimens of octocorals off Mauritania. Micro-computed tomography (micro-CT) reveals, for the first time in taxon...

A review was done on all species of the genus Talassia (family Vanikoridae Gray, 1840), which are known from an upper bathyal depth range in the Atlantic Ocean. Four new species are proposed: Talassia mexicana sp. nov. from the Gulf of Mexico, T. laevapex sp. nov. and T. flexisculpta sp. nov. from off Mauritania and T. rugosa sp. nov. from off Ango...

Studies of marine microbioerosion in polar environments are scarce. They include our recent investigations of bioerosion traces preserved in sessile balanid skeletons from the Arctic Svalbard archipelago and the Antarctic Ross Sea. Here, we present results from a third study site, Frobisher Bay, in the eastern Canadian Arctic, together with a synth...

Marine symbioses are integral to the persistence of ecosystem functioning in coral reefs. Solitary corals of the species Heteropsammia cochlea and Heterocyathus aequicostatus have been observed to live in symbiosis with the sipunculan worm Aspidosiphon muelleri muelleri, which inhabits a cavity within the coral, in Zanzibar (Tanzania). The symbiosi...

How does the line of zero-Ekman pumping (LZE) evolve in the northeast Atlantic since the last glacial? What is the impact of climate changes on cold-water coral (CWC) populations on seamounts? Do seamount sediments and weathering influence the trace isotope composition of seawater? These questions have been in the focus of the RV METEOR cruise M151...

Cold‐water coral reefs constitute important biodiversity hotspots in aphotic waters around the world. The complex, highly variable morphology of the reef habitat‐forming species has important implications for the communities they harbor and for the physical processes occurring therein. Lophelia pertusa (Desmophyllum pertusum) is one of the most com...

Three new species in the family Rissoidae (Gastropoda) have been found in bioclastic sediment samples taken on the bathyal slopes of two Azorean seamount areas during the cruise M151 Athena by R/V Meteor: Alvania templadoi n. sp., Crisilla avilai n. sp. and Crisilla herosae n. sp. A review of endemicity in bathyal rissoids is presented; the large m...

Rhodolith beds and bioherms formed by ecosystem engineering crustose coralline algae support the northernmost centres of carbonate production, referred to as polar cold-water carbonate factories. Yet, little is known about biodiversity and recruitment of these hard-bottom communities or the bioeroders degrading them, and there is a demand for carbo...

Hyrrokkin sarcophaga is a parasitic foraminifera that is commonly found in cold-water coral reefs where it infests the file clam Acesta excavata and the scleractinian coral Desmophyllum pertusum (formerly known as Lophelia pertusa). Here, we present measurements of the trace element and isotopic composition of these parasitic foraminifera, analyzed...

Four species in the genus Anatoma Woodward, 1859 were found in bioclastic sediment samples taken on the bathyal slopes of seven Azorean seamounts during the cruises SEA-MOUNT 2 by R/V LE SUROIT and M151 ATHENA by R/V METEOR. Three new species are proposed: Anatoma bisculpta n. sp., Anatoma symmetrica n. sp. and Anatoma pagoda n. sp. The former two...

This study aims to map the occurrence and distribution of Madrepora oculata and to quantify density and colony sizes across recently discovered coral mounds off Angola. Despite the fact that the Angolan populations of M. oculata thrive under extreme hypoxic conditions within the local oxygen minimum zone, they reveal colonies with remarkable height...

Microscopic organisms that penetrate calcareous structures by actively dissolving the carbonate matrix, namely microendoliths, have an important influence on the breakdown of marine carbonates. The study of these microorganisms and the bioerosion traces they produce is crucial for understanding the impact of their bioeroding activity on the carbona...

High-resolution proxy records are needed to evaluate models simulating past, present and future climatic conditions. Before such records can be reliably employed, calibration studies have to be conducted to assess the confidence intervals of the proxies. Here, we use shells of the fast growing Pacific oyster Magallana gigas from the Central Wadden...

Breakdown of skeletal and lithic hard substrates by organisms, a process referred to as bioerosion, is part of the global carbon cycle and receives increased attention, but little is known about bioerosion in polar environments. Here, we study bioerosion traces (addressed by their respective ichnotaxa) recorded in the barnacle Bathylasma corollifor...

Hyrrokkin sarcophaga is a parasitic foraminifer that is commonly found in cold-water coral reefs where it infests the file clam Acesta excavata and the scleractinian coral Lophelia pertusa. Here, we present measurements of the elemental and isotopic composition of this parasitic foraminifer for the first time, analyzed by inductively coupled optica...

A diverse set of 31 species in Eulimidae have been found on the bathyal slopes of the Azorean seamounts during cruise R/V Meteor cruise M151. A total of 44 bathyal eulimids are currently known from the area. 13 eulimids reported by earlier studies have not been encountered; this is considered a result of limited sampling across the large sub-sea ar...

Forty-six “skeneimorph” species from the South Azorean Seamount Chain (SASC) have been studied. These comprise taxa in the superfamilies Trochoidea (family Skeneidae) and Seguenzioidea (families Trochaclididae, Pendromidae, Eudaroniidae and several genera which are not assigned to a family). Seventeen new species are proposed, fifteen in Seguenzioi...

In this paper, two new species of the genus Rosalinda found growing on bivalves from West African cold-water coral mounds are described. Rosalinda nowaldi sp. nov. was found on Acesta angolensis (Adam & Knudsen, 1955) off northern Angola, and Rosalinda lundalvi sp. nov. on Acesta excavata (Fabricius, 1779) off Mauritania. Both new species have a si...

This first comprehensive investigation of microbioerosion traces in polar barnacles addresses two bathymetrical transects from the intertidal down to subtidal water depths in two different carbonate factories in the Svalbard Archipelago: the bay Mosselbukta and the ocean bank Bjørnøy-Banken. Scanning electron microscopy of epoxy resin casts of...

Reefs formed by scleractinian cold-water corals represent unique biodiversity hot spots in the deep sea, preferring aphotic water depths of 200–1000 m. The distribution of the most prominent reef-building species Lophelia pertusa is controlled by various environmental factors including dissolved oxygen concentrations and temperature. Consequently,...

A new species, Cantrainea mauritanea n. sp. (Gastropoda: Collonidae) has been described from deep-water coral (DWC) habitats off Mauritania. The new taxon is the third known species in Cantrainea from the NE Atlantic Ocean.

The deep sea plays a critical role in global climate regulation through uptake and storage of heat and carbon dioxide. However, this regulating service causes warming, acidification and deoxygenation of deep waters, leading to decreased food availability at the seafloor. These changes and their projections are likely to affect productivity, biodive...

Cold-water corals (CWC), dominantly Desmophyllum pertusum (previously Lophelia pertusa), and their mounds have been in the focus of marine research during the last two decades; however, little is known about the mound-forming capacity of other CWC species. Here, we present new 230Th/U age constraints of the relatively rarely studied framework-build...

Eleven species of the genus Papuliscala de Boury, 1911 (Epitoniidae Berry, 1910) were collected on the South Azorean Seamount Chain (SASC), ten of them described as new: Papuliscala dictyophora n. sp., P. seamountae n. sp., P. platoensis n. sp., P. carolienae n. sp., P. luuki n. sp., P. daani n. sp., P. meteorica n. sp., P. atlantisa n. sp., P. vix...

Six species belonging to the family Seguenziidae collected on the South Azorean Seamount Chain (SASC) have been studied. Three species are described as new: Basilissopsis athenae n. sp., Carenzia marismontis n. sp., and Asthelys hyeresensis n. sp. The distributions of these new taxa are probably restricted to the bathyal crests and slopes of the SA...

Thriving benthic communities were observed in the oxygen minimum zones along the southwestern African margin. On the Namibian margin, fossil cold-water coral mounds were overgrown by sponges and bryozoans, while the Angolan margin was characterized by cold-water coral mounds covered by a living coral reef. To explore why benthic communities differ...

This study reports four vesicomyid species of the bathyal zone collected in sediment samples off the Mauritanian continental slope. One species is described as new: Isorropodon arguinensis spec. nov. Three bathyal species Waisiuconcha haeckeli, Isorropodon curtum, Callogonia mauritanica are already known from Mauritania and all four are most likely...

A new species in the family Philobryidae is described from offshore Namibia: Neocardia kandeli n. sp. Empty shells and valves were found in silty sediment containing remains of a deep-water coral habitat in about 230 m. The bivalve is named to honour Prof. Eric Richard Kandel, recipient of the 2000 Nobel Prize in Physiology or Medicine.

An exceptionally large cold-water coral mound province (CMP) was recently discovered extending over 80 km along the Namibian shelf (offshore southwestern Africa) in water depths of 160–270 m. This hitherto unknown CMP comprises >2000 mounds with heights of up to 20 m and constitutes the largest CMP known from the southeastern Atlantic Ocean. Uraniu...

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 an...

Mapping biodiversity is the marathon of the 21 st Century as an answer to the present extinction crisis. A century in which science is also characterised by large scientific datasets collected through new technologies aiming to fill gaps in our knowledge of species distributions. However, most species records rely on observations that are not linke...

The fate of bathyal coral communities prior, during and after the environmentally devastating Messinian Salinity Crisis is briefly reviewed. The Messinian Salinity Crisis has created a geologically short-termed but massive disruption to marine life in the Late Miocene Mediterranean Sea. First signs of deteriorating environmental conditions begun ab...

I mound a coralli profondi, costruiti da sclerattinari di acque fredde come Lophelia pertusa e Madrepora oculata, sono diffusi lungo tutta la piattaforma della Scandinavia e nei fiordi, aree completamente ricoperte dai ghiacci durante l’ultimo massimo glaciale tra 22 e 18 ka BP. Il ritiro dei ghiacci ha rapidamente liberato la maggior parte della p...

Three species in the gastropod genus Calliostoma are confirmed as living in Deep-Water Coral (DWC) habitats in the NE Atlantic Ocean: Calliostoma bullatum (Philippi, 1844), C. maurolici (Seguenza, 1876) and C. leptophyma Dautzenberg & Fischer, 1896. Up to now, C. bullatum was only known as fossil from Early to Mid-Pleistocene outcrops in DWC-relate...

Columbellidae (Gastropoda) have been studied from deep-water coral (DWC) habitats off Mauritania. Three new species have been described: Retizafra macumae n. sp., Retizafra tamxatensis n. sp. and Zemitrella bandaensis n. sp. One additional unknown columbellid species is mentioned but not described due to inadequate material. More common species are...

A new species Vexillum monscorallum n.sp. (Gastropoda: Costellariidae) has been described from deep-water coral habitats off Mauritania. The generic classification needs to be revised once live-collected specimens become available.

Fossil cold-water coral mounds overgrown by sponges and bryozoans were observed in anoxic conditions on the Namibian margin, while mounds colonized by thriving cold-water coral reefs were found in hypoxic conditions on the Angolan margin. These low oxygen conditions do not meet known environmental ranges favoring cold-water corals and hence are exp...

Here we present a comprehensive attempt to correlate aragonitic Na / Ca ratios from 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 content usi...

Zoological nomenclature revisions are essential for biodiversity studies and indispensable to avoid naming and description of already described species and should be valued in all subsequent studies considering biology, molecular biology, ecology or habitat mapping of deep-sea species. Herein, a thorough revision of the taxonomic literature on Octo...

Knowledge on Azorean octocorals is still dispersed in several taxonomical papers and monographs. Moreover it is hard to find and written in different languages representing a challenge for zoological nomenclature and taxonomic studies. Taxonomic literature about octocorals (orders Alcyonacea and Pennatulacea) inhabiting the Azores marine waters wa...

Four species in Lepetella (Lepetellidae) have been recognized in the fauna of North Atlantic Deep–Water Coral (DWC) habitats: Lepetella ionica F. Nordsieck, 1973, L. sierrai Dantart & Luque, 1994, L. tubicola Verrill & Smith, 1880, and L. wisshaki n. sp. Lepetella ionica has been found in DWC habitats on both sides of the North Atlantic. Lepetella...

Various species are discussed in the genera Ganesa, Lopheliella and Trochaclis. Ganesa nitidiuscula Jeffreys, 1883 has been found in a wide N Atlantic distribution area in deep-water corals (DWC). Lopheliella coralfishae n. sp. and Ganesa poseidonae n. sp. are described. Trochaclis versiliensis has been recorded in DWC habitats in the Porcupine are...

Four cribrilinid bryozoans associated with deep-water corals (578–682 m depth) from the Great Bahama Bank slope, are described, two of them are new. The generic allocation of some species prompted us to raise the subgenera Puellina, Cribrilaria, and Glabrilaria to genus rank. The new combination Cribrilaria saginata (Winston, 2005) n. comb. is prop...

Fissurellid species found in deep-water coral (DWC) habitats off Mauritania have been reviewed. The first evidence of the extant status of Fissurisepta papillosa is confirmed by one live specimen. Diodora tenuiclathrata and Cranopsis asturiana have also been found alive. The living fissurellids are considered remnants of Pleistocene fauna that mana...

Four Chauvetia species have been found in deep-water coral habitats off Mauritania. Three of them are described as new: Chauvetia mauritania n. sp., Chauvetia merianae n. sp. and Chauvetia poseidonae n. sp., while the fourth species (Chauvetia bartolomeoi Ardovini, 2008) is known from shallower water on the NW African Shelf.

Specimens of the genus Acanthogorgia (Acanthogorgiidae, Octocorallia) show different sclerite types in the colonie parts like axis coenenchym, polyps and tentacles. Applying high resolution images and three dimensional µCT-scans we compared five Acanthogorgia species (A. aspera, A. armata, A. granulata, A. hirta, A. muricata) from the North Atlanti...

A new species of caprellid amphipod, Aeginella corallina sp. nov., is described from cold-water corals off Angola. This is the first observation of this genus in the South-Atlantic. The taxon is fully described and figured and is compared with the only known species of the genus, A. spinosa, occurring in deep waters of the northern hemisphere. Both...

A description is provided of two new calliotropid species. A new genus, Toroidia (Gastropoda: Calliotropidae) has been based on unique morphological features of three species, named Toroidia merianae n. sp., Toroidia toroides (Hoffman, van Heugten & Lavaleye, 2009) and Toroidia porcupinensis n. sp. A large number of Toroidia merianae have been foun...