Carnivorous sponges of the Atlantic and Arctic Oceans. Phylogeny, taxonomy, distribution and microbial associations of the Cladorhizidae (Demospongiae, Poecilosclerida)

The sponges (phylum Porifera) are defined by the presence of an aquiferous system in which choanoflagellate cells create a current and filter water flowing through the sponge body. The carnivorous sponges represent the only known exception to filter feeding within the phylum, and instead are able to capture prey including small crustaceans and larval plankton, using a combination of an adhesive surface and numerous filaments suitable for entangling prey. Mobile cells are able to slowly cover prey entangled on the surface of the sponge, and prey items are encapsulated and digested in a process that can last several days. The aquiferous system is either strongly reduced or entirely absent in the carnivorous sponges, which typically have an erect pennate, branching or stipitate pedunculate morphology. Carnivory is usually considered an adaptation to deep-sea conditions, where filter feeding is less efficient due to a lower density of suspended particulate matter. An exceptional evolutionary innovation within the phylum, sponge carnivory was not properly known to science until 1995. Interest in carnivorous sponges have been high in recent years, and over 150 species are currently considered valid, up from some 90 known species at the turn of the millennium. Carnivorous sponges are found within the demosponge order Poecilosclerida, defined by the presence of skeletal chela microsclere spicules. Almost all carnivorous sponges have traditionally been assigned to Cladorhizidae, with a few species assigned to Guitarridae (Euchelipluma) and Esperiopsidae (five Esperiopsis spp.). As spicule morphology is the main diagnostic character in sponge systematics, the large diversity of chela forms found within the genera assigned to Cladorhizidae implies the possibility that the family is polyphyletic, and that carnivory has evolved in several independent poecilosclerid lineages. On the other hand, recent molecular studies have shown that spicule morphology is often more plastic and intricate than previously believed. Thus the question of whether carnivorous sponges represent a monophyletic group is currently unanswered. Recent studies have greatly expanded the number and known distribution of carnivorous sponges, which are now known to be present at a variety of depths worldwide. Still, as deep-sea sponges, records are comparably sparse. The greatest number of records is from the North Atlantic. However, records are scattered, and species descriptions frequently lacking in detail. In other areas of the Atlantic and worldwide, species are typically known only from a few or even one collection event. As they have an affinity to the deep sea, carnivorous sponges are often reported in the vicinity of vent and seep sites. In one particular instance, chemoautotrophic symbiosis has been reported between the carnivorous sponge Cladorhiza methanophila and methanotrophic prokaryotes from the Barbados Accretionary Prism. The extent of this type of symbiosis within the group is unknown, however, and though general sponge microbiome data is increasingly published as NGS studies have become more prevalent, almost no such data is currently published for carnivorous sponges. Answering a number of current questions connected to carnivorous sponges, the aims of this thesis include (1) elucidating the systematic relationships of the carnivorous sponges using molecular data, (2) presenting a taxonomic inventory of carnivorous sponges focusing on Atlantic species, and (3) conducting a comparative study of the microbial community of several cladorhizid species including C. methanophila using mainly 16S rRNA Ion Torrent data. The work presented here provides a comprehensive phylogenetic analysis containing representatives of almost all carnivorous sponge groups, including species not traditionally included in Cladorhizidae, as well as an outgroup sampling of noncarnivorous relatives. The phylogenetic study is able to show that carnivorous sponges represent a monophyletic group, strengthening the hypothesis that carnivory only has evolved once within the sponges, and assigning all carnivorous sponges to Cladorhizidae. Furthermore, this work shows the position of Cladorhizidae relative to other poecilosclerid families, and is able to reconstruct cladorhizid relationships at the genus and subgenus level in most cases. Using an integrated taxonomical approach, molecular data and morphological characters are combined to create an updated classification for all known carnivorous sponges. The thesis adds to, and includes an overview of the known cladorhizid species diversity in different regions of the Atlantic Ocean. It offers a comprehensive overview of the cladorhizid fauna of the boreal North Atlantic and Arctic, including descriptions of 25 species and an overview of their known distributions, and explores the cladorhizid fauna of the abyssal Atlantic and Caribbean and adjacent areas respectively. A summary of known carnivorous sponges for the Atlantic Ocean in general, with a discussion on the relationships of the regional Atlantic faunas, is also presented, as well as observations on the depth preference of different species. Finally, this thesis also presents a comparative examination of 16S rRNA microbiome and isotope data from several carnivorous sponge species including Cladorhiza methanophila. Results show that cladorhizid sponges have rich microbial communities, which partially overlap between species. No further evidence of major chemoautotrophic symbiosis was found in species other than C. methanophila, where methanotrophic bacteria were abundant, suggesting that this species is likely an exception within carnivorous sponges in general. There is currently a high degree of interest in carnivorous sponges. As more morphological, molecular and biogeographic data is published, refinements to both the systematics, taxonomical diversity, function and ecology of this group are expected, further building on the results presented in this thesis and giving a more complete picture of the known diversity, evolutionary history and biogeography of the Cladorhizidae

The cladorhizid fauna (Porifera, Poecilosclerida) of the Caribbean and adjacent waters

The carnivorous sponge family Cladorhizidae has been subject to several recent studies, yet the cladorhizid fauna of the Caribbean and adjacent areas remain comparatively poorly known. In this article we provide a description of the novel species Abyssocladia polycephalus sp. nov. from the Muir Seamount NE of Bermuda, belonging to the mainly Pacific genus Abyssocladia, and Asbestopluma (Asbestopluma) caribica sp. nov. from the Beata Ridge. Additionally, we provide a re-description of the poorly known species Chondrocladia (Chondrocladia) verticillata Topsent, 1920, and compare this species with the closely related species C. (C.) concrescens Schmidt, 1880. Finally, we provide a brief overview of the carnivorous sponges known from the Gulf of Mexico, Caribbean Sea and adjacent Atlantic Ocean.publishedVersio

Environmental DNA monitoring of pelagic fish fauna at the Hywind Scotland floating wind energy installation – A pilot study

Environmental impact assessment and regular environmental monitoring are prerequisites for the construction, operation, and decommissioning of offshore installations such as the Hywind Scotland wind park. Molecular approaches are increasingly being considered as a possible complement or alternative to currently used marine baseline and monitoring methods, both for pelagic and benthic organism studies. The following report is a proof-of-concept study where two molecular methods, metabarcoding and quantitative assays, have been used to characterize the pelagic environment at the Hywind Scotland wind park based on filtered water samples from the installation and a reference area. The purpose of the report is to showcase the use of molecular methodology in future studies of the pelagic ecosystem. Metabarcoding was employed for a community view of a) fish species specifically, using the MiFish primer set, and b) a universal eukaryote dataset based on 18S V1-V2 primers. Quantitative assays were employed for two commercially important pelagic fish species: mackerel and herring.publishedVersio

The Microbiome and Occurrence of Methanotrophy in Carnivorous Sponges

As shown by recent studies, filter-feeding sponges are known to host a wide variety of microorganisms. However, the microbial community of the non-filtering carnivorous sponges (Porifera, Cladorhizidae) has been the subject of less scrutiny. Here, we present the results from a comparative study of the methanotrophic carnivorous sponge Cladorhiza methanophila from a mud volcano-rich area at the Barbados Accretionary Prism, and five carnivorous species from the Jan Mayen Vent Field (JMVF) at the Arctic Mid-Ocean Ridge. Results from 16S rRNA microbiome data indicate the presence of a diverse assemblage of associated microorganisms in carnivorous sponges mainly from the Gamma- and Alphaproteobacteria, Flavobacteriaceae, and Thaumarchaeota. While the abundance of particular groups varied throughout the dataset, we found interesting similarities to previous microbiome results from non-carnivorous deep sea sponges, suggesting that the carnivorous sponges share characteristics of a previously hypothesized putative deep-sea sponge microbial community. Chemolithoautotrophic symbiosis was confirmed for C. methanophila through a microbial community with a high abundance of Methylococcales and very light isotopic δ13C and δ15N ratios (-60 to -66‰/3.5 to 5.2‰) compared to the other cladorhizid species (-22 to -24‰/8.5 to 10.5‰). We provide evidence for the presence of putative sulfur-oxidizing Gammaproteobacteria in the arctic cladorhizids; however, δ13C and δ15N signatures did not provide evidence for significant chemoautotrophic symbiosis in this case, and the slightly higher abundance of cladorhizids at the JMVF site compared to the nearby deep sea likely stem from an increased abundance of prey rather than a more direct vent association. The phylogenetic position of C. methanophila in relation to other carnivorous sponges was established using a three-gene phylogenetic analysis, and it was found to be closely related to other non-methanotrophic Cladorhiza species with a similar morphology included in the dataset, suggesting a recent origin for methanotrophy in this species. C. methanophila remains the only known carnivorous sponge with a strong, chemolithoautotrophic symbiont association, and methanotrophic symbiosis does not seem to be a widespread property within the Cladorhizidae.publishedVersio

Wind and Fisheries: Desktop Study on the Coexistence Between Offshore Wind and Fisheries in Sothern North Sea II

The Norwegian Government has launched a major initiative to promote offshore wind power , in which bottom-fixed wind power will be developed in the Southern North Sea II (SN II) area. There is a low level of fishing activities in this area with varying catch sizes over the years. The activities consist nearly exclusively of bottom trawling of sandeel. The fishing industry has raised concerns about the development of offshore wind farms (OWFs), including risks for collision and hindrance for fishing vessels, negative impacts on fish stocks, and other ecosystem-wide effects. This report has conducted a data study and compiled existing literature on these topics to, based on best available science, assess how OWF development could affect fisheries in SN II, the possibilities for facilitating coexistence for these two industries, and potential synergies. While the development of OWFs in SN II has the potential to bring both positive and negative effects on the fisheries as well as the marine life in the area, the findings suggest that coexistence between the two industries is possible. Potential impacts, including noise, magnetic fields, turbidity, artificial reef and FAD effects, and no-fishing zones, have not been shown to adversely affect populations of commercially important fish at OWF developments in the North Sea. With the ongoing technology shift to larger turbines, the space between each turbine is increasing, which may reduce collision risk. Seafloor cables can also be sufficiently buried to reduce the risk of damage by demersal trawls. Furthermore, most types of passive fishing gear (except for drifting nets) and practices are less problematic to use in an OWF. Should, though, the construction of OWFs in SN II cause restrictions on the fishery activities in the area, it is likely to cause increased fishing in other areas, often referred to in the scientific literature as the displacement effect, indicating that the economic loss will be smaller than the estimated catch values. Notable knowledge gaps are regarding positive and negative long term cumulative impacts and regional effects, impact on primary production and carbon assimilation from changed upper ocean mixing and impact from floating wind farms (not relevant in SN II). We emphasise the importance of early and ongoing input from relevant stakeholders to address concerns and find optimal mitigation measures for minimising the OWF footprint in SN II during the different phases of OWF development.Wind and Fisheries: Desktop Study on the Coexistence Between Offshore Wind and Fisheries in Sothern North Sea IIpublishedVersio

Arctic Paleoceanography Cruise KH21-234 with R/V Kronprins Haakon

We set sail from Longyearbyen on 30.6.2021 to collect surface sediments, long sediment archives, water and plankton samples. The study area is located north of Svalbard, within the seasonal and permanent sea ice covered Arctic Ocean. We took stations N of Svalbard, near Nordaustlandet, Sophia Basin, Yermak Plateau and on the shelf east of Svalbard. In total, we had 52 stations. We deployed the multicorer at least once at every station and sampled the core tops already onboard. These samples will be included in the Arctic Surface Sediment DNA Database, which we will use to establish new aDNA based sea ice proxies. We recovered gravity cores from 12 stations that can be used to reconstruct the Arctic sea ice history in the Holocene, last glacial and likely also Last Interglacial. We collected ice and water and filtered these for eDNA and biomarkers, and water for tracing the isotope signal of the different water masses in the region (Atlantic Water, Polar Water).publishedVersio

Kunnskapsstatus for bruk av molekylære verktøy i kartlegging og overvåkning av biologisk mangfold i marine miljø

Source at https://www.miljodirektoratet.no/publikasjoner/2021/juni-2021/kunnskapsstatus-for-bruk-av-molekylare-verktoy-i-kartlegging-og-overvakning-av-biologisk-mangfold-i-marine-miljo/Denne rapporten er bestilt av Miljødirektoratet fra NorBOL (Norwegian Barcode of Life), et nasjonalt nettverk av forskningsinstitusjoner som koordineres av NTNU Vitenskapsmuseet. Universitetsmuseet i Bergen har hatt prosjektledelsen. Rapporten gir en oppsummering av dagens status på DNA-basert metodikk som verktøy i kartlegging og overvåking av biologisk mangfold i det marine miljø. Fokus har vært på innsamlingsmetodikk og protokoller for DNA-analyser av arter og artsgrupper. Metodikken er evaluert opp mot kartleggings- og overvåkingsaktivitet i regi av Miljødirektoratet, og kommer med anbefalinger for videre framdrift for å ta metodikken i bruk i nasjonal kartlegging og overvåking. Rapporten har også en gjennomgang og evaluering av eksisterende referansemateriale og referansesekvenser for relevante arter og artsgrupper som inngår i Miljødirektoratets kartleggings- og overvåkingsaktivitet

Carnivorous sponges of the Atlantic and Arctic Oceans. Phylogeny, taxonomy, distribution and microbial associations of the Cladorhizidae (Demospongiae, Poecilosclerida)

The sponges (phylum Porifera) are defined by the presence of an aquiferous system in which choanoflagellate cells create a current and filter water flowing through the sponge body. The carnivorous sponges represent the only known exception to filter feeding within the phylum, and instead are able to capture prey including small crustaceans and larval plankton, using a combination of an adhesive surface and numerous filaments suitable for entangling prey. Mobile cells are able to slowly cover prey entangled on the surface of the sponge, and prey items are encapsulated and digested in a process that can last several days. The aquiferous system is either strongly reduced or entirely absent in the carnivorous sponges, which typically have an erect pennate, branching or stipitate pedunculate morphology. Carnivory is usually considered an adaptation to deep-sea conditions, where filter feeding is less efficient due to a lower density of suspended particulate matter. An exceptional evolutionary innovation within the phylum, sponge carnivory was not properly known to science until 1995. Interest in carnivorous sponges have been high in recent years, and over 150 species are currently considered valid, up from some 90 known species at the turn of the millennium. Carnivorous sponges are found within the demosponge order Poecilosclerida, defined by the presence of skeletal chela microsclere spicules. Almost all carnivorous sponges have traditionally been assigned to Cladorhizidae, with a few species assigned to Guitarridae (Euchelipluma) and Esperiopsidae (five Esperiopsis spp.). As spicule morphology is the main diagnostic character in sponge systematics, the large diversity of chela forms found within the genera assigned to Cladorhizidae implies the possibility that the family is polyphyletic, and that carnivory has evolved in several independent poecilosclerid lineages. On the other hand, recent molecular studies have shown that spicule morphology is often more plastic and intricate than previously believed. Thus the question of whether carnivorous sponges represent a monophyletic group is currently unanswered. Recent studies have greatly expanded the number and known distribution of carnivorous sponges, which are now known to be present at a variety of depths worldwide. Still, as deep-sea sponges, records are comparably sparse. The greatest number of records is from the North Atlantic. However, records are scattered, and species descriptions frequently lacking in detail. In other areas of the Atlantic and worldwide, species are typically known only from a few or even one collection event. As they have an affinity to the deep sea, carnivorous sponges are often reported in the vicinity of vent and seep sites. In one particular instance, chemoautotrophic symbiosis has been reported between the carnivorous sponge Cladorhiza methanophila and methanotrophic prokaryotes from the Barbados Accretionary Prism. The extent of this type of symbiosis within the group is unknown, however, and though general sponge microbiome data is increasingly published as NGS studies have become more prevalent, almost no such data is currently published for carnivorous sponges. Answering a number of current questions connected to carnivorous sponges, the aims of this thesis include (1) elucidating the systematic relationships of the carnivorous sponges using molecular data, (2) presenting a taxonomic inventory of carnivorous sponges focusing on Atlantic species, and (3) conducting a comparative study of the microbial community of several cladorhizid species including C. methanophila using mainly 16S rRNA Ion Torrent data. The work presented here provides a comprehensive phylogenetic analysis containing representatives of almost all carnivorous sponge groups, including species not traditionally included in Cladorhizidae, as well as an outgroup sampling of noncarnivorous relatives. The phylogenetic study is able to show that carnivorous sponges represent a monophyletic group, strengthening the hypothesis that carnivory only has evolved once within the sponges, and assigning all carnivorous sponges to Cladorhizidae. Furthermore, this work shows the position of Cladorhizidae relative to other poecilosclerid families, and is able to reconstruct cladorhizid relationships at the genus and subgenus level in most cases. Using an integrated taxonomical approach, molecular data and morphological characters are combined to create an updated classification for all known carnivorous sponges. The thesis adds to, and includes an overview of the known cladorhizid species diversity in different regions of the Atlantic Ocean. It offers a comprehensive overview of the cladorhizid fauna of the boreal North Atlantic and Arctic, including descriptions of 25 species and an overview of their known distributions, and explores the cladorhizid fauna of the abyssal Atlantic and Caribbean and adjacent areas respectively. A summary of known carnivorous sponges for the Atlantic Ocean in general, with a discussion on the relationships of the regional Atlantic faunas, is also presented, as well as observations on the depth preference of different species. Finally, this thesis also presents a comparative examination of 16S rRNA microbiome and isotope data from several carnivorous sponge species including Cladorhiza methanophila. Results show that cladorhizid sponges have rich microbial communities, which partially overlap between species. No further evidence of major chemoautotrophic symbiosis was found in species other than C. methanophila, where methanotrophic bacteria were abundant, suggesting that this species is likely an exception within carnivorous sponges in general. There is currently a high degree of interest in carnivorous sponges. As more morphological, molecular and biogeographic data is published, refinements to both the systematics, taxonomical diversity, function and ecology of this group are expected, further building on the results presented in this thesis and giving a more complete picture of the known diversity, evolutionary history and biogeography of the Cladorhizidae

Cladorhizid sponges from hydrothermal vents and cold seeps in the NE Atlantic Ocean

Sponges are known to frequently contain a great number of symbiotic organisms. Symbiosis is also a characteristic trait of vent and seep animals worldwide. Sponges in the deep sea family Cladorhizidae, otherwise also known for their surprising ability to capture invertebrate prey, are among the most common sponges found in proximity to vents, and in one reported case methanotrophic symbiotic bacteria have been described in a cladorhizid species at a mud volcano. The phylogenetic relationships within the Cladorhizidae and between the cladorhizids and sister families are uncertain. New species of Cladorhizidae are still discovered, even in comparatively well studied areas such as the North Atlantic, and their affinity to vent systems make them likely candidates for harboring methanotrophic symbionts. The 2006-2009 R/V G.O. Sars" cruises to methane rich habitats in the Norwegian and Arctic Seas have yielded a number of cladorhizid specimens. This thesis contains a taxonomic inventory of these specimens using traditional morphological methods, and the results of sequencing the Folmer COI, and ITS partitions of the identified species. Lastly, the pmoA partition of the gene coding for particulate methane monooxygenase in known methanotrophic bacteria, was sequenced as a method to determine the presence of any methanotrophic symbionts from the specimens sampled. Morphological results showed that the R/V G.O. Sars" material contained six Asbestopluma and three Cladorhiza species. With the exception of two species affiliated to A. lycopodium, all were previously described species from the North Atlantic and Arctic. Though obtaining sequences proved challenging due to contamination from other organisms, cloning allowed the separation of cladorhizid and contaminant sequences, and it proved possible to get COI and ITS sequences from nearly all morphologically identified species. ITS sequences proved too divergent for phylogenetic analysis; however Folmer COI sequences had a level of resolution applicable both to place the Cladorhizidae within the broader Poecilosclerida group, close to Mycalidae, and to resolve internal relationships within the Cladorhizidae. The COI results suggest that Asbestopluma might be paraphyletic, though additional data are needed to draw more robust conclusions. Sequencing of the pmoA partition met with mixed results. It proved possible to prove the presence of the gene in small quantities in some samples, but contamination and lack of ambient controls made it difficult to draw any strong conclusions as to the origin of the sequences

Grab what you can—an evaluation of spatial replication to decrease heterogeneity in sediment eDNA metabarcoding

Environmental DNA methods such as metabarcoding have been suggested as possible alternatives or complements to the current practice of morphology-based diversity assessment for characterizing benthic communities in marine sediment. However, the source volume used in sediment eDNA studies is several magnitudes lower than that used in morphological identification. Here, we used data from a North Sea benthic sampling station to investigate to what extent metabarcoding data is affected by sampling bias and spatial heterogeneity. Using three grab parallels, we sampled five separate sediment samples from each grab. We then made five DNA extraction replicates from each sediment sample. Each extract was amplified targeting both the 18S SSU rRNA V1–V2 region for total eukaryotic composition, and the cytochrome c oxidase subunit I (COI) gene for metazoans only. In both datasets, extract replicates from the same sediment sample were significantly more similar than different samples from the same grab. Further, samples from different grabs were less similar than those from the same grab for 18S. Interestingly, this was not true for COI metabarcoding, where the differences within the same grab were similar to the differences between grabs. We also investigated how much of the total identified richness could be covered by extract replicates, individual sediment samples and all sediment samples from a single grab, as well as the variability of Shannon diversity and, for COI, macrofaunal biotic indices indicating environmental status. These results were largely consistent with the beta diversity findings, and show that total eukaryotic diversity can be well represented using 18S metabarcoding with a manageable number of biological replicates. Based on these results, we strongly recommend the combination of different parts of the surface of single grabs for eDNA extraction as well as several grab replicates, or alternatively box cores or similar. This will dilute the effects of dominating species and increase the coverage of alpha diversity. COI-based metabarcoding consistency was found to be lower compared to 18S, but COI macrofauna-based indices were more consistent than direct COI alpha diversity measures.publishedVersio