Project

H2020 SponGES - Deep-sea Sponge Grounds Ecosystems of the North Atlantic: an integrated approach towards their preservation and sustainable exploitation

Goal: SponGES is a research and innovation project funded under the H2020 Blue Growth BG1 call aimed at “Improving the preservation and sustainable exploitation of Atlantic marine ecosystems”. Its overarching goal is to develop an integrated ecosystem-based approach to preserve and sustainably use deep-sea sponge ecosystems of the North Atlantic. Its consortium, an international and interdisciplinary collaboration of 19 European and North American research institutions, environmental non-governmental and intergovernmental organizations, will focus on one of the most diverse, ecologically and biologically important and vulnerable marine ecosystems of the deep-sea - sponge grounds – that have received very little research and conservation attention to date. Over the course of four years, from March 2016 - Feb 2020, SponGES will:
1 - Strengthen the knowledge-base on North Atlantic sponge ground ecosystems by investigating their distribution, diversity, biogeography, function and dynamics;
2 - Improve innovation and industrial application by unlocking the biotechnological potential of these ecosystems;
3 - Improve the capacity to model, understand and predict threats and impacts and future anthropogenic and climate-driven changes to these ecosystems;
4 - Advance the science-policy interface and developing tools for improved resource management and good governance of these ecosystems from regional to international levels across the North Atlantic.

Want to know more? Follow us on:
www.deepseasponges.org
https://www.facebook.com/Deep-Sea-Sponges-1101396993244491/
https://twitter.com/DeepSea_Sponges


*SponGES has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 679849

Date: 1 March 2016 - 28 February 2020

Updates
0 new
3
Recommendations
0 new
3
Followers
0 new
190
Reads
5 new
2006

Project log

Pilar Ríos
added a research item
Macro and megafauna were studied in the Aviles Canyon System (ACS), southern Bay of Biscay (Cantabrian Sea), during several oceanographic cruises carried out from 2009 to 2017. The biodiversity of ACS is summarized and its description is herein updated after sampling surveys of several programmes (ECOMARG, INDEMARES, SponGES) conducted by the Spanish Institute of Oceanography (IEO). This study has updated previous knowledge in the canyon area from past national and international projects, their reports and publications as well as data collected in the context of regional projects designed to gain new insight into the diversity of marine invertebrates and fishes from the ACS. Samples were taken using a range of sampling gears (Rock dredge, Beam trawl, Trawl gear GOC-73, Suprabenthic sledge, Box corer and Remoted operated vehicle), from 55 to 2291 m in depth. A total of 1011 species were identified at the ACS: 98 Porifera, 153 Cnidaria, 14 Brachiopoda, 22 Bryozoa, 97 Mollusca, 151 Annelida, 311 Arthropoda, 74 Echinodermata and 91 Chordata. New records for the Bay of Biscay fauna include 13 Porifera species, 17 Cnidaria, 7 Mollusca, 8 Arthopoda, 3 Echinodermata and 4 Chordata. Also the bathymetric range of some species has been extended. As a result of the research projects carried out in the area in the last fifteen years (ECOMARG, INDEMARES, SponGES, INTEMARES), important information is now available which suggests that the ACS houses a large number of several, including species with a high ecological value, and that it represents a biodiversity hotspot in terms of the presence of sponge aggregations and coral reefs in certain regions and sustains important fisheries due to the abundance of comercial species. Given the relevance of the species and habitats occurring in the ACS, there is a need to implement a conservation and management plan of the area in order to maintain habitats in good state of preservation.
Javier Cristobo
added a research item
This work focuses on the study of habitats and communities of a high structural complexity area at different levels and scales. This gives us a better understanding of an area from an ecological point of view and at the same time provides us with tools that will facilitate management measures. It was developed in a complex circalittoral rocky platform of the central Cantabrian Sea (Bay of Biscay). The sampling was carried out using a towed photogrammetric vehicle and a rock dredge, which was used for the identification of the species. The first level of the study was the abiotic characterization of the area and the analysis of the communities. These analysis were developed using the unsupervised k-means classification method. For abiotic characterization we used the variables directly associated with the composition and morphology of the ground, such as backscatter, BPI (Bathymetric Position Index), roughness and slope. Depth was also included to discriminate between the circalittoral and bathyal zones. We obtained 5 different classes, which we related to the ground types observed by photogrammetry. In the analysis of the communities, the cluster was based on the sampling units extracted from the images (∼10m), from which 5 assemblages were obtained, providing information on the most abundant species of each class supplied by the abiotic study. The second level was carried out considering a management approach and was based on the modeling of the area at lower resolution, more suitable for the analysis of the habitat-fisheries interactions. Thus, the main habitat-forming species (HFS) of the entire circalittoral area were used to perform delta models based on GAMs (Generalize Additive Models). Obtaining the predictions of presence/absence and combining it with the predictions of densities, we got the zero inflated values density-based model. As all the identified habitats have vulnerable benthic species of a certain size settled on rocky bottoms, they can all be considered to belong to the designation 1170 reefs of the Habitats Directive.
Paco Cárdenas
added a research item
Sponges contain an astounding diversity of lipids that serve in several biological functions, including yolk formation in their oocytes and embryos. The study of lipid metabolism during reproduction can provide information on food-web dynamics and energetic needs of the populations in their habitats, however, there are no studies focusing on the lipid metabolism of sponges during their seasonal reproduction. In this study, we used histology, lipidome profiling (UHPLC-MS), and transcriptomic analysis (RNA-seq) on the deep-sea sponge Phakellia ventilabrum (Demospongiae, Bubarida), a key species of North-Atlantic sponge grounds, with the goal to (i) assess the reproductive strategy and seasonality of this species, (ii) examine the relative changes in the lipidome signal and the gene expression patterns of the enzymes participating in lipid metabolism during oogenesis. Phakellia ventilabrum is an oviparous and most certainly gonochoristic species, reproducing in May and September in the different studied areas. Half of the specimens were reproducing, generating two to five oocytes per mm ² . Oocytes accumulated lipid droplets and as oogenesis progressed, the signal of most of the unsaturated and monounsaturated triacylglycerides increased, as well as of a few other phospholipids. In parallel, we detected upregulation of genes in female tissues related to triacylglyceride biosynthesis and others related to fatty acid beta-oxidation. Triacylglycerides are likely the main type of lipid forming the yolk in P. ventilabrum since this lipid category has the most marked changes. In parallel, other lipid categories were engaged in fatty acid beta-oxidation to cover the energy requirements of female individuals during oogenesis. In this study, the reproductive activity of the sponge P. ventilabrum was studied for the first time uncovering their seasonality and revealing 759 lipids, including 155 triacylglycerides. Our study has ecological and evolutionary implications providing essential information for understanding the molecular basis of reproduction and the origins and formation of lipid yolk in early-branching metazoans.
Emyr Martyn Roberts
added a research item
Deep-sea sponges inhabit multiple areas of the deep North Atlantic at depths below 250 m. Living in the deep ocean, where environmental properties below the permanent thermocline generally change slowly, they may not easily acclimatize to abrupt changes in the environment. Until now consistent monitoring timeseries of the environment at deep sea sponge habitats are missing. Therefore, long-term simulation with coupled bio-physical models can shed light on the changes in environmental conditions sponges are exposed to. To investigate the variability of North Atlantic sponge habitats for the past half century, the deep-sea conditions have been simulated with a 67-year model hindcast from 1948 to 2014. The hindcast was generated using the ocean general circulation model HYCOM, coupled to the biogeochemical model ECOSMO. The model was validated at known sponge habitats with available observations of hydrography and nutrients from the deep ocean to evaluate the biases, errors, and drift in the model. Knowing the biases and uncertainties we proceed to study the longer-term (monthly to multi-decadal) environmental variability at selected sponge habitats in the North Atlantic and Arctic Ocean. On these timescales, these deep sponge habitats generally exhibit small variability in the water-mass properties. Three of the sponge habitats, the Flemish Cap, East Greenland Shelf and North Norwegian Shelf, had fluctuations of temperature and salinity in 4–6 year periods that indicate the dominance of different water masses during these periods. The fourth sponge habitat, the Reykjanes Ridge, showed a gradual warming of about 0.4°C over the simulation period. The flux of organic matter to the sea floor had a large interannual variability, that, compared to the 67-year mean, was larger than the variability of primary production in the surface waters. Lateral circulation is therefore likely an important control mechanism for the influx of organic material to the sponge habitats. Simulated oxygen varies interannually by less than 1.5 ml/l and none of the sponge habitats studied had oxygen concentrations below hypoxic levels. The present study establishes a baseline for the recent past deep conditions that future changes in deep sea conditions from observations and climate models can be evaluated against.
Paco Cárdenas
added a research item
Marine sponges (phylum Porifera) are leading organisms for the discovery of bioactive compounds from nature. Their often rich and species-specific microbiota is hypothesised to be producing many of these compounds. Yet, environmental influences on the sponge-associated microbiota and bioactive compound production remain elusive. Here, we investigated the changes of microbiota and metabolomes in sponges along a depth range of 1232 m. Using 16S rRNA gene amplicon sequencing and untargeted metabolomics, we assessed prokaryotic and chemical diversities in three deep-sea sponge species: Geodia barretti, Stryphnus fortis, and Weberella bursa. Both prokaryotic communities and metabolome varied significantly with depth, which we hypothesized to be the effect of different water masses. Up to 35.5% of microbial ASVs (amplicon sequence variants) showed significant changes with depth while phylum-level composition of host microbiome remained unchanged. The metabolome varied with depth, with relative quantities of known bioactive compounds increasing or decreasing strongly. Other metabolites varying with depth were compatible solutes regulating osmolarity of the cells. Correlations between prokaryotic community and the bioactive compounds in G. barretti suggested members of Acidobacteria, Proteobacteria, Chloroflexi, or an unclassified prokaryote as potential producers.
Anna De Kluijver
added a research item
The Central Arctic Ocean is one of the most oligotrophic oceans on Earth because of its sea-ice cover and short productive season. Nonetheless, across the peaks of extinct volcanic seamounts of the Langseth Ridge (87°N, 61°E), we observe a surprisingly dense benthic biomass. Bacteriosponges are the most abundant fauna within this community, with a mass of 460 g C m ⁻² and an estimated carbon demand of around 110 g C m ⁻² yr ⁻¹ , despite export fluxes from regional primary productivity only sufficient to provide <1% of this required carbon. Observed sponge distribution, bulk and compound-specific isotope data of fatty acids suggest that the sponge microbiome taps into refractory dissolved and particulate organic matter, including remnants of an extinct seep community. The metabolic profile of bacteriosponge fatty acids and expressed genes indicate that autotrophic symbionts contribute significantly to carbon assimilation. We suggest that this hotspot ecosystem is unique to the Central Arctic and associated with extinct seep biota, once fueled by degassing of the volcanic mounts.
Javier Cristobo
added a research item
Sponges are amongst the most diffi cult benthic taxa to properly identify, which has led to a prevalence of cryptic species in several sponge genera, especially in those with simple skeletons. This is particularly true for sponges living in remote or hardly accessible environments, such as the deep-sea, as the inaccessibility of their habitat and the lack of accurate descriptions usually leads to misclassifications. However, species can also remain hidden even when they belong to genera that haveparticularly characteristic features. In these cases, researchers inevitably pay attention to these peculiar features, sometimes disregarding small differences in the other “typical” spicules. The genus Melonanchora Carter, 1874, is among those well suited for a revision, as their representatives possess a unique type of spicule (spherancorae). After a thorough review of the material available for this genus from several institutions, four new species of Melonanchora, M. tumultuosa sp. nov., M. insulsa sp. nov., M. intermedia sp. nov. and M. maeli sp. nov. are formally described from different localities across the Atlanto-Mediterranean region. Additionally, all Melonanchora from the Okhotsk Sea and nearby areas are reassigned to other genera; Melonanchora kobjakovae is transferred to Myxilla (Burtonanchora) while two new genera, Hanstoreia gen. nov. and Arhythmata gen. nov. are created to accommodate Melonanchora globogilva and Melonanchora tetradedritifera, respectively. Hanstoreia gen. nov. is closest to Melonanchora, whereas Arhythmata gen. nov., is closer to Stelodoryx, which is most likely polyphyletic and in need of revision.
Paco Cárdenas
added a research item
Natural product discovery by isolation and structure elucidation is a laborious task often requiring ample quantities of biological starting material and frequently resulting in the rediscovery of previously known compounds. However, peptides are a compound class amenable to an alternative genomic, transcriptomic, and in silico discovery route by similarity searches of known peptide sequences against sequencing data. Based on the sequences of barrettides A and B, we identified five new barrettide sequences (barrettides C–G) predicted from the North Atlantic deep-sea demosponge Geodia barretti (Geodiidae). We synthesized, folded, and investigated one of the newly described barrettides, barrettide C (NVVPCFCVEDETSGAKTCIPDNCDASRGTNP, disulfide connectivity I–IV, II–III). Co-elution experiments of synthetic and sponge-derived barrettide C confirmed its native conformation. NMR spectroscopy and the anti-biofouling activity on larval settlement of the bay barnacle Amphibalanus improvisus (IC50 0.64 μM) show that barrettide C is highly similar to barrettides A and B in both structure and function. Several lines of evidence suggest that barrettides are produced by the sponge itself and not one of its microbial symbionts.
Ellen L. Kenchington
added a research item
Vulnerable marine ecosystems (VMEs) are particularly susceptible to bottom-fishing activity as they are easily disturbed and slow to recover. A data-driven approach was developed to provide management options for the protection of VMEs under the European Union “deep-sea access regulations.” A total of two options within two scenarios were developed. The first scenario defined VME closure areas without consideration of fishing activity. Option 1 proposed closures for the protection of VME habitats and likely habitat, while Option 2 also included areas where four types of VME geophysical elements were present. The second scenario additionally considered fishing. This scenario used VME biomass—fishing intensity relationships to identify a threshold where effort of mobile bottom-contact gears was low and unlikely to have caused significant adverse impacts. Achieving a high level of VME protection requires the creation of many closures (> 100), made up of many small (∼50 km2) and fewer larger closures (> 1000 km2). The greatest protection of VMEs will affect approximately 9% of the mobile fleet fishing effort, while closure scenarios that avoid highly fished areas reduce this to around 4–6%. The framework allows managers to choose the level of risk-aversion they wish to apply in protecting VMEs by comparing alternative strategies.
Ellen L. Kenchington
added a research item
Sponges (phylum Porifera) are benthic filter feeding animals that play an important role in nutrient cycling and habitat provision in the deep sea. Sponges collected between 2010 and 2014 during annual multispecies trawl surveys conducted by Fisheries and Oceans Canada in Baffin Bay, Davis Strait and portions of Hudson Strait were taxonomically examined. In total ~2500 specimens were identified, comprising ~100 known sponge taxa. Sponges from the order Poecilosclerida comprised nearly half of the identified species. Sponges from the poescilosclerid families Coelosphaeridae, Crellidae, Dendoricellidae, Myxillidae, Tedaniidae, Microcionidae, Acarnidae and Esperiopsidae are described in previous reports. This report adds descriptions of five sponge species from two poescilosclerid families: Mycalidae and Isodictyidae (class Demospongiae, subclass Heteroscleromorpha, order Poecilosclerida). Described species include Mycale (Mycale) lingua, Mycale (Mycale) cf. toporoki, Mycale (Mycale) cf. loveni and Mycale (Rhaphidotheca) marshallhalli, all from the family Mycalidae, and Isodictya aff. palmata from the family Isodictyidae. Descriptions include physical description of the sponges, descriptions and dimensions of their spicules, and taxonomic discussion.
Ellen L. Kenchington
added 2 research items
Effective conservation management of deep-sea sponges, including design of appropriate marine protected areas, requires an understanding of the connectivity between populations throughout a species' distribution. We provide the first consideration of larval connectivity among deep-sea sponge populations along the southeastern coast of North America, illustrate the influence of the Gulf Stream on dispersal, and complement published distribution models by evaluating colonization potential. Connectivity among known populations of the hexactinellid sponge Vazella pourtalesii was simulated using a 3-D biophysical dispersal model throughout its distribution from Florida, United States to Nova Scotia, Canada. We found no exchange with an estimated pelagic larval duration of 2 weeks between populations north and south of Cape Hatteras, North Carolina at surface, mid-water and seabed release depths, irrespective of month of release or application of a horizontal diffusion constant specific to cross-Gulf Stream diffusivity. The population north of Cape Hatteras and south of Cape Cod was isolated. There was some evidence that Gulf Stream eddies formed near Cape Hatteras could travel to the northwest, connecting the populations in the two sub-regions, however that would require a much longer pelagic duration than what is currently known. More likely almost all larval settlement will be in the immediate area of the adults. At sub-regional scales, connectivity was found from the Strait of Florida through to the Blake Plateau, southeastern United States, with the latter area showing potential for recruitment from more than one source population. The influence of the Charleston Bump, a shallow feature rising from the Blake Plateau, was substantial. Particles seeded just north of the Bump were transported greater distances than those seeded to the south, some of which were caught in an associated gyre, promoting retention at the seabed. To the north on the Scotian Shelf, despite weaker currents and greater distances between known occurrences, unidirectional transport was detected from Emerald Basin to the Northeast Channel between Georges and Browns Banks. These major conclusions remained consistent through simulations run with different averaging periods for the currents (decades to daily) and using two ocean model products (BNAM and GLORYS12V1).
Furu Mienis
added a research item
Deep‐sea sponge grounds are hotspots of benthic biomass and diversity. To date, very limited data exist on the range of environmental conditions in areas containing deep‐sea sponge grounds and which factors are driving their distribution and sustenance. We investigated oceanographic conditions at a deep‐sea sponge ground located on an Arctic Mid‐Ocean Ridge seamount. Hydrodynamic measurements were performed along Conductivity‐Temperature‐Depth transects, and a lander was deployed within the sponge ground that recorded near‐bottom physical properties as well as vertical fluxes of organic matter over an annual cycle. The data demonstrate that the sponge ground is found at water temperatures of −0.5°C to 1°C and is situated at the interface between two water masses at only 0.7° equatorward of the turning point latitude of semi‐diurnal lunar internal tides. Internal waves supported by vertical density stratification interact with the seamount topography and produce turbulent mixing as well as resuspension of organic matter with temporarily very high current speeds up to 0.72 m s⁻¹. The vertical movement of the water column delivers food and nutrients from water layers above and below toward the sponge ground. Highest organic carbon flux was observed during the summer phytoplankton bloom period, providing fresh organic matter from the surface. The flux of fresh organic matter is unlikely to sustain the carbon demand of this ecosystem. Therefore, the availability of bacteria, nutrients, and dissolved and particulate matter, delivered by tidally forced internal wave turbulence and transport by horizontal mean flows, likely plays an important role in meeting ecosystem‐level food requirements.
Joana R. Xavier
added a research item
Lithistid sponges are globally distributed in temperate and subtropical areas, constituting an important component of deep-sea benthic communities where they form structurally complex and vulnerable marine ecosystems (VMEs). In this study, we assess the diversity and investigate the spatial and bathymetric distribution of the lithistid sponges of the Azores archipelago (North Atlantic) based on historical records and examination of samples accidentally collected during deep-sea longline fishing operations in the region. Eleven lithistid species are recognized to occur in the Azores, including Leiodermatium tuba, recently described from material collected in several Northeast Atlantic seamounts that is hereby reported for the first time to the archipelago. We provide molecular barcodes (mtDNA COI and rRNA 28S) for seven of these species, including Discodermia ramifera, Macandrewia azorica, and Exsuperantia archipelagus, for which the Azores constitutes the type locality. We further discuss the phylogenetic and biogeographic affinities of the Azorean lithistids in the context of the Porifera classification, and the wider Northeast Atlantic upper bathyal fauna. Our study also warrants the addition of some lithistid species to the list of VME indicators for the Northeast Atlantic in support of the sustainable management and conservation of these species and habitats, as well as the ecological functions they deliver.
Paco Cárdenas
added a research item
Geodia barretti is a deep-sea marine sponge common in the north Atlantic and waters outside of Norway and Sweden. The sampling and subsequent treatment as well as storage of sponges for metabolomics analyses can be performed in different ways, the most commonly used being freezing (directly upon collection or later) or by storage in solvent, commonly ethanol, followed by freeze-drying. In this study we therefore investigated different sampling protocols and their effects on the detected metabolite profiles in liquid chromatography-mass spectrometry (LC-MS) using an untargeted metabolomics approach. Sponges (G. barretti) were collected outside the Swedish west coast and pieces from three sponge specimens were either flash frozen in liquid nitrogen, frozen later after the collection cruise, stored in ethanol or stored in methanol. The storage solvents as well as the actual sponge pieces were analyzed, all samples were analyzed with hydrophilic interaction liquid chromatography as well as reversed phase liquid chromatography with high resolution mass spectrometry using full-scan in positive and negative ionization mode. The data were evaluated using multivariate data analysis. The highest metabolite intensities were found in the frozen samples (flash frozen and frozen after sampling cruise) as well as in the storage solvents (methanol and ethanol). Metabolites extracted from the sponge pieces that had been stored in solvent were found in very low intensity, since the majority of metabolites were extracted to the solvents to a high degree. The exception being larger peptides and some lipids. The lowest variation between replicates were found in the flash frozen samples. In conclusion, the preferred method for sampling of sponges for metabolomics was found to be immediate freezing in liquid nitrogen. However, freezing the sponge samples after some time proved to be a reliable method as well, albeit with higher variation between the replicates. The study highlights the importance of saving ethanol extracts after preservation of specimens for biology studies; these valuable extracts could be further used in studies of natural products, chemosystematics or metabolomics.
Ellen L. Kenchington
added a research item
Hexactinellid sponges are common in the deep sea, but their functional integration into those ecosystems remains poorly understood. The phylogenetically related species Schaudinnia rosea and Vazella pourtalesii were herein incubated for nitrogen and phosphorous, returning markedly different nutrient fluxes. Transmission electron microscopy (TEM) revealed S. rosea to host a low abundance of extracellular microbes, while Vazella pourtalesii showed higher microbial abundance and hosted most microbes within bacteriosyncytia, a novel feature for Hexactinellida. Amplicon sequences of the microbiome corroborated large between-species differences, also between the sponges and the seawater of their habitats. Metagenome-assembled genome of the V. pourtalesii microbiota revealed genes coding for enzymes operating in nitrification, denitrification, dissimilatory nitrate reduction to ammonium, nitrogen fixation, and ammonia/ammonium assimilation. In the nitrification and denitrification pathways some enzymes were missing, but alternative bridging routes allow the microbiota to close a N cycle in the holobiont. Interconnections between aerobic and anaerobic pathways may facilitate the sponges to withstand the low-oxygen conditions of deep-sea habitats. Importantly, various N pathways coupled to generate ammonium, which, through assimilation, fosters the growth of the sponge microbiota. TEM showed that the farmed microbiota is digested by the sponge cells, becoming an internal food source. This microbial farming demands more ammonium that can be provided internally by the host sponges and some 2.6 million kg of ammonium from the seawater become annually consumed by the aggregations of V. pourtalesii. Such ammonium removal is likely impairing the development of the free-living bacterioplankton and the survival chances of other sponge species that feed on bacterioplankton. Such nutritional competitive exclusion would favor the monospecific character of the V. pourtalesii aggregations. These aggregations also affect the surrounding environment through an annual release of 27.3 million kg of nitrite and, in smaller quantities, of nitrate and phosphate. The complex metabolic integration among the microbiota and the sponge suggests that the holobiont depends critically on the correct functioning of its N-driven microbial engine. The metabolic intertwining is so delicate that it changed after moving the sponges out of their habitat for a few days, a serious warning on the conservation needs of these sponge aggregations.
Pilar Ríos
added a research item
In the present work we focus on the distribution of two species of sponges. One of these is Asconema setubalense, a sponge found in rocky substrate that was sampled with a photogrammetric vehicle through georeferenced images. The other is Pheronema carpenteri, which inhabits soft bottoms and was sampled by beam trawl. For the spatial distribution modeling of both sponges, the geomorphological variables of depth, slope, broad and fine scale bathymetric position index (BPI), aspect, and types of bottoms were used, all with a resolution of 32 m. Additionally, layers of silicates and currents near the bottom were extracted from Copernicus Marine Environment Monitoring Service (CMEMS), with a resolution of ∼4 and ∼9 km, respectively. Due to the low resolution of the layers, it was considered necessary to validate their use by model comparison, where those that included these variables turned out to be more explanatory than the others. The models were developed in a complex continental break of the Central Cantabrian Sea, which comprises several submarine canyons and a seamount (Le Danois Bank). On the one hand, a very high resolution (32 m) spatial distribution model based on A. setubalense presence was developed using the MaxEnt maximum entropy model. On the other, depending on the availability of density data, generalized additive models (GAMs) were developed for P. carpenteri distribution, although in this case the sampler only allowed a maximum resolution of almost 1 Km. For the A. setubalense, the variables that best explained their distribution were ground types and depth, and for P. carpenteri, silicates, slope, northness, and eastward seawater velocity. The final model scores obtained were an AUC of 0.98 for the MaxEnt model, and an R squared of 0.87 for the GAM model.
Pilar Ríos
added a research item
A new Tedania species (Porifera) was collect using remotely operated vehicles during the Canadian mission HUD2010-029 and the British RRS Discovery Cruise DY081, on the Orphan Seamount near the Orphan Knoll, northwest Atlantic, between 2999.88 and 3450.4 m depth. Orphan Knoll is an isolated, drowned continental fragment 550 km northeast Newfoundland in the Labrador Sea. This region is biologically rich and complex and in 2007, the regional fisheries management organization operating in the area regulated that no vessel shall engage in bottom-contact fishing activities until reviewed in 2020 with a review slated at the end of this year. Members of the genus Tedania are uncommon in the temperate northern hemisphere with only six species known previously: Tedania (Tedania) anhelans; Tedania (Tedania) pilarriosae; Tedania (Tedania) suctoria; Tedania (Tedania) urgorrii; Tedania (Tedaniopsis) gurjanovae; and Tedania (Tedaniopsis) phacellina. The particular features of the new sponge we describe are the very peculiar external morphology which is tree-like with dichotomous branching-a morphology not previously described in this subgenus; and the combination of spicules found: long styles, the typical tornotes of the subgenus and two sizes of onychaetes. Additional information is provided on other species of Tedaniopsis described from the Atlantic Ocean. Based on the characteristics reported, we propose a new species, Tedania (Tedaniopsis) rappi sp. nov. in honor of Prof. Hans Tore Rapp (1972-2020), University of Bergen, Norway, a renowned sponge taxonomist and coordinator of the Horizon 2020 SponGES project. The holotype of T. (T.) phacellina Topsent, 1912 from the Azores, the only other northern Atlantic species in the subgenus Tedaniopsis, was reviewed for comparison.
Emyr Martyn Roberts
added 3 research items
Seamounts represent ideal systems to study the influence and interdependency of environmental gradients at a single geographic location. These topographic features represent a prominent habitat for various forms of life, including microbiota and macrobiota, spanning benthic as well as pelagic organisms. While it is known that seamounts are globally abundant structures, it still remains unclear how and to which extent the complexity of the sea floor is intertwined with the local oceanographic mosaic, biogeochemistry, and microbiology of a seamount ecosystem. Along these lines, the present study aimed to explore whether and to what extent seamounts can have an imprint on the microbial community composition of seawater and of sessile benthic invertebrates, sponges. For our high-resolution sampling approach of microbial diversity (16S rRNA gene amplicon sequencing) along with measurements of inorganic nutrients and other biogeochemical parameters, we focused on the Schulz Bank seamount ecosystem, a sponge ground ecosystem which is located on the Arctic Mid-Ocean Ridge. Seawater samples were collected at two sampling depths (mid-water, MW, and near-bed water, BW) from a total of 19 sampling sites. With a clustering approach we defined microbial microhabitats within the pelagic realm at Schulz Bank, which were mapped onto the seamount's topography and related to various environmental parameters (such as suspended particulate matter, SPM; dissolved inorganic carbon, DIC; silicate, SiO4-; phosphate, PO43-; ammonia, NH4+; nitrate, NO32-; nitrite, NO2-; depth; and dissolved oxygen, O2). The results of our study reveal a “seamount effect” (sensu stricto) on the microbial mid-water pelagic community at least 200 m above the sea floor. Further, we observed a strong spatial heterogeneity in the pelagic microbial landscape across the seamount, with planktonic microbial communities reflecting oscillatory and circulatory water movements, as well as processes of bentho-pelagic coupling. Depth, NO32-, SiO4-, and O2 concentrations differed significantly between the determined pelagic microbial clusters close to the sea floor (BW), suggesting that these parameters were presumably linked to changes in microbial community structures. Secondly, we assessed the associated microbial community compositions of three sponge species along a depth gradient of the seamount. While sponge-associated microbial communities were found to be mainly species-specific, we also detected significant intra-specific differences between individuals, depending on the pelagic near-bed cluster they originated from. The variable microbial phyla (i.e. phyla which showed significant differences across varying depth, NO32-, SiO4-, O2 concentrations, and different from local seawater communities) were distinct for every sponge species when considering average abundances per species. Variable microbial phyla included representatives of both those taxa traditionally counted for the variable community fraction and taxa counted traditionally for the core community fraction. Microbial co-occurrence patterns for the three examined sponge species Geodia hentscheli, Lissodendoryx complicata, and Schaudinnia rosea were distinct from each other. Over all, this study shows that topographic structures such as the Schulz Bank seamount can have an imprint (seamount effect sensu lato) on both the microbial community composition of seawater and sessile benthic invertebrates such as sponges by an interplay between the geology, physical oceanography, biogeochemistry, and microbiology of seamounts.
Few studies have described the effects of physical disturbance and post-recovery of deep-sea benthic communities. Here, we explore the status of deep-sea sponge ground communities four years after being impacted by an experimental bottom trawl. The diversity and abundance of epibenthic megafauna of two distinct benthic communities in disturbed versus control areas were surveyed using a remotely operated vehicle on the Schulz Bank, Arctic Ocean. Four years after disturbance, megafaunal densities of the shallow (∼600 m depth) and deep (∼1,400 m depth) sites were significantly lower on the disturbed patches compared to the control areas. Multivariate analyses revealed a distinct separation between disturbed and control communities for both sites, with trawling causing 29–58% of the variation. Many epibenthic morphotypes were significantly impacted by the trawl, including ascidians, Geodia parva , Hexactinellida spp., Craniella infrequens , Lissodendoryx complicata , Haliclonia sp. Stylocordyla borealis , Gersemia rubiformis and Actiniaria sp. However, we found some smaller morphospecies to be equally abundant with control transects, including Polymastia thielei , Geodia hentscheli , and Stelletta rhaphidiophora , reflecting lower trawl impact for these morphotypes. Overall, our results suggest that these are fragile ecosystems that require much more time than four years to recover from physical disturbance typical of trawling activities.
Water masses are bodies of water with distinctive physical and biogeochemical properties. They impart vertical structure to the deep ocean, participate in circulation, and can be traced over great distances, potentially influencing the distributions of deep-sea fauna. The classic potential temperature-salinity ( θ - s ) diagram was used to investigate deep-sea sponge (demosponge genus Geodia ) association with water masses over the North Atlantic Ocean and Nordic Seas. A novel analysis was conducted, based on sampling the curvature of climatological mean θ - s curves at sponge locations. Sponges were particularly associated with turning points in the θ - s curves, indicative of intermediate and deep water masses. Arctic geodiid species ( G. hentscheli and G. parva ) were associated with Arctic intermediate and deep waters in the Nordic Seas, and with dense overflows into the northern North Atlantic. Boreal species ( G. atlantica , G. barretti , G. macandrewii , and G. phlegraei ) were associated with upper and intermediate water masses in the Northeast Atlantic and with upper, Atlantic-derived waters in the Nordic Seas. Taken together with distributional patterns, a link with thermohaline currents was also inferred. We conclude that water masses and major current pathways structure the distribution of a key deep-sea benthic faunal group on an ocean basin scale. This is most likely because of a combination of the physical constraints they place on the dispersal of early life-history stages, ecophysiological adaptation (evolved tolerances) to specific water masses, and the benefits to filter-feeders of certain phenomena linked to water column structure (e.g. nepheloid layers, internal waves/tides, density-driven currents).
Pilar Ríos
added a research item
We describe the first application of a non-invasive and novel approach to estimate the growth rate of Asconema setubalense (Porifera, Hexactinellida) through the use of 3D photogrammetric methodology. Structure-from-Motion techniques (SfM) were applied to videos acquired with the Politolana ROTV in the El Cachucho Marine Protected Area (MPA) (Cantabrian Sea) on three different dates (2014, 2017, and 2019) over six years. With these data, a multi-temporal study was conducted within the framework of MPA monitoring. A complete 3D reconstruction of the deep-sea floor was achieved with Pix4D Mapper Pro software for each date. Having 3D point clouds of the study area enabled a series of measurements that were impossible to obtain in 2D images. In 3D space, the sizes (height, diameter, cup-perimeter, and cup-surface area) of several A. setubalense specimens were measured each year. The annual growth rates recorded ranged from zero ("no growth") for a large size specimen, to an average of 2.2 cm year −1 in cup-diameter, and 2.5 cm year −1 in height for developing specimens. Von Bertalanffy growth parameters were estimated. Taking into account the size indicators used in this study and based on the von Bertalanffy growth model, this sponge reaches 95% maximum size at 98 years of age. During the MPA monitoring program, a high number of specimens disappeared. This raised suspicions of a phenomenon affecting the survival of this species in the area. This type of image-based methodology does not cause damage or alterations to benthic communities and should be employed in vulnerable ecosystem studies and MPA monitoring.
Anna De Kluijver
added a research item
Sponges produce distinct fatty acids (FAs) that (potentially) can be used as chemotaxonomic and ecological biomarkers to study endosymbiont-host interactions and the functional ecology of sponges. Here, we present FA profiles of five common habitat-building deep-sea sponges (class Demospongiae, order Tetractinellida), which are classified as high microbial abundance (HMA) species. Geodia hentscheli , G . parva , G . atlantica , G . barretti , and Stelletta rhaphidiophora were collected from boreal and Arctic sponge grounds in the North-Atlantic Ocean. Bacterial FAs dominated in all five species and particularly isomeric mixtures of mid-chain branched FAs (MBFAs, 8- and 9-Me-C 16:0 and 10- and 11-Me-C 18:0 ) were found in high abundance (together ≥ 20% of total FAs) aside more common bacterial markers. In addition, the sponges produced long-chain linear, mid- and a(i)- branched unsaturated FAs (LCFAs) with a chain length of 24‒28 C atoms and had predominantly the typical Δ 5,9 unsaturation, although the Δ 9,19 and (yet undescribed) Δ 11,21 unsaturations were also identified. G . parva and S . rhaphidiophora each produced distinct LCFAs, while G . atlantica , G . barretti , and G . hentscheli produced similar LCFAs, but in different ratios. The different bacterial precursors varied in carbon isotopic composition (δ ¹³ C), with MBFAs being more enriched compared to other bacterial (linear and a ( i )-branched) FAs. We propose biosynthetic pathways for different LCFAs from their bacterial precursors, that are consistent with small isotopic differences found in LCFAs. Indeed, FA profiles of deep-sea sponges can serve as chemotaxonomic markers and support the concept that sponges acquire building blocks from their endosymbiotic bacteria.
Anna De Kluijver
added a research item
Deep-sea sponges and their microbial symbionts transform various forms of carbon (C) and nitrogen (N) via several metabolic pathways, which, for a large part, are poorly quantified. Previous flux studies on the common deep-sea sponge Geodia barretti consistently revealed net consumption of dissolved organic carbon (DOC) and oxygen (O 2) and net release of nitrate (NO − 3). Here we present a biogeochemical metabolic network model that, for the first time, quantifies C and N fluxes within the sponge holobiont in a consistent manner, including many poorly constrained metabolic conversions. Using two datasets covering a range of individual G. barretti sizes (10-3,500 ml), we found that the variability in metabolic rates partially resulted from body size as O 2 uptake allometrically scales with sponge volume. Our model analysis confirmed that dissolved organic matter (DOM), with an estimated C:N ratio of 7.7 ± 1.4, is the main energy source of G. barretti. DOM is primarily used for aerobic respiration, then for dissimilatory NO − 3 reduction to ammonium (NH + 4) (DNRA), and, lastly, for denitrification. Dissolved organic carbon (DOC) production efficiencies (production/assimilation) were estimated as 24 ± 8% (larger individuals) and 31 ± 9% (smaller individuals), so most DOC was respired to carbon dioxide (CO 2), which was released in a net ratio of 0.77-0.81 to O 2 consumption. Internally produced NH + 4 from cellular excretion and DNRA fueled nitrification. Nitrification-associated chemoautotrophic production contributed 5.1-6.7 ± 3.0% to total sponge production. While overall metabolic patterns were rather independent of sponge size, (volume-)specific rates were lower in larger sponges compared to smaller individuals. Specific biomass production rates were 0.16% day −1 in smaller compared to 0.067% day −1 in larger G. barretti as expected for slow-growing deep-sea organisms. Collectively, our approach shows that metabolic modeling of hard-to-reach, deep-water sponges can be used to predict community-based biogeochemical fluxes and sponge production that will facilitate further investigations on the functional integration and the ecological significance of sponge aggregations in deep-sea ecosystems.
Private Profile
added a research item
Sponges occur ubiquitously in the marine realm and in some deep-sea areas they dominate the benthic communities forming complex biogenic habitats-sponge grounds, aggregations, gardens and reefs. However, deep-sea sponges and sponge-grounds are still poorly investigated with regards to biotechnological potential in support of a Blue growth strategy. Under the scope of this study, five dominant North Atlantic deep-sea sponges, were characterized to elucidate promising applications in human health, namely for bone tissue engineering approaches. Geodia barretti (Gb), Geodia atlantica (Ga), Stelletta normani (Sn), Phakellia ventilabrum (Pv), and Axinella infundibuliformis (Ai), were morphologically characterized to assess macro and microstructural features, as well as chemical composition of the skeletons, using optical and scanning electron microscopy, energy dispersive x-ray spectroscopy and microcomputed tomography analyses. Moreover, compress tests were conducted to determine the mechanical properties of the skeletons. Results showed that all studied sponges have porous skeletons with porosity higher than 68%, pore size superior than 149 µm and higher interconnectivity (>96%), thus providing interesting models for the development of scaffolds for tissue engineering. Besides that, EDS analyses revealed that the chemical composition of sponges, pointed that demosponge skeletons are mainly constituted by carbon, silicon, sulfur, and oxygen combined mutually with organic and inorganic elements embedded its internal architecture that can be important features for promoting bone matrix quality and bone mineralization. Finally, the morphological, mechanical, and chemical characteristics here investigated unraveled the potential of deep-sea sponges as a source of biomaterials and biomimetic models envisaging tissue engineering applications for bone regeneration.
Paco Cárdenas
added a research item
Siliceous spicules in demosponges exist in a variety of shapes, some of which look like minute spheres of glass. They are called “sterrasters” when they belong to the Geodiidae family (Tetractinellida order) and “selenasters” when they belong to the Placospongiidae family (Clionaida order). Today, the Geodiidae represent a highly diverse sponge family with more than 340 species, occurring in shallow to deep waters worldwide, except for the Antarctic. The molecular phylogeny of Geodiidae is currently difficult to interpret because we are lacking morphological characters to support most of its clades. To fill this knowledge gap, the surface microornamentations of sterrasters were compared in different genera. Observations with scanning electron microscopy revealed four types of surfaces, which remarkably matched some of the Geodiidae genera: type I characteristic of Geodia , type II characteristic of Pachymatisma, Caminus , and some Erylus ; type III characteristic of other Erylus ; type IV characteristic of Caminella . Two subtypes were identified in Geodia species: warty vs. smooth rosettes. These different microornamentations were mapped on new Geodiidae COI (Folmer fragment) and 28S (C1–D2) phylogenetic trees. The monophyly of the Geodiidae was once again challenged, thereby suggesting that sterrasters have evolved independently at least three times: in the Geodiinae, in the Erylinae and in Caminella . Surface microornamentations were used to review the fossil record of sterrasters and selenasters through the paleontology literature and examination of fossils. It was concluded that “rhaxes” in the literature may represent mixes of sterrasters and selenasters: while Rhaxella spicules may belong to the Placospongiidae, Rhaxelloides spicules belong to the Geodiidae. The putative Geodiidae fossil genera, Geoditesia , and Geodiopsis , are reallocated to Tetractinellida incertae sedis . Isolated Miocene-Pliocene fossil sterrasters Hataina ( Huang, 1967 ), Silicosphaera ( Hughes, 1985 ) and Conciliaspongia ( Robinson and Haslett, 1995 ) become junior synonyms of Geodia ( Lamarck, 1815 ). Overall, the fossil record suggested that Geodiidae was present at least since the Middle Jurassic (163–166 Mya), while Geodia sterrasters were present since the Santonian/Campanian boundary, Late Cretaceous (83.6 Mya). ZooBank Article Registration urn:lsid: zoobank.org :pub:91B1B3AC-8862-4751-B272-8A3BDF4DEE77.
Pilar Ríos
added a research item
This study analyzes the fauna composition of the community of brittle and sea stars associated with sponge aggregations located in Avilés Canyons System and El Cachucho, Marine Protected Area (MPA). Diverse sampling methods were used depending on bottom morphology, such as rock dredges and specific samplers for sedimentary bottoms, mainly beam trawl models. These banks are made up of sponge and coral species that build a very appropriate substrate for the proliferation of benthic species, which together create Vulnerable Marine Ecosystems that are highly relevant for management and conservation. Among these benthic species, echinoderms are of great interest due to their value as indicators of good habitat. In total, 1261 specimens were collected (934 brittle stars and 327 starfishes), belonging to 42 species (28 ophiuroids and 14 asteroids) from INDEMARES AVILÉS, ECOMARG, and SponGES project surveys. Specimens were distributed among four sponge aggregations (F: fields) that were considered according to the sponge records obtained in the same stations (36). These fields were defined and named based on the five most common sponge species: Aphrocallistes beatrix and Regadrella phoenix (F1: Avilés Canyon); Pheronema carpenteri (F2: Intraslope basin of Le Danois Bank); Asconema setubalense (F3: Le Danois Bank); and Neoschrammeniella aff. bowerbankii (F4: Corbiro Canyon). Faunistic results show that Ophiactis abyssicola (55.55% occurrence), Brisinga endecacnemos, Ophiolycus purpureus , and Peltaster placenta (33.33%) were the most frequently found species in F1; Psilaster andromeda (80%), Pseudarchaster parelii (60%), and Nymphaster arenatus (46.67%) in F2; Ophiura carnea (71.43%) and Ophiacantha smitti (42.86%) in F3; and Ophiacantha densa , and Henricia caudani (100%) in F4. The asteroid and ophiuroid species collected seem to be composed of four different communities that fit to areas with particular morphological and biological features, related to the presence of species specialized in the use of the resources they can find there. In general, the abiotic factor controlling this structure is depth. This assemblage structure, which favors the dissimilarity between the canyons and the bank, is not so clear, since the deepest stations are located on the intraslope basin of El Cachucho, Marine Protected Area (MPA), therefore, using it a priori could lead to misunderstandings. Once the structure of the echinoderm community was known, we compared the expected and obtained results to analyze evidence which should prove the existence of any association between echinoderms and sponges, which enabled us to refute the incongruous hypothesis.
Paco Cárdenas
added a research item
Boreo-arctic sponge grounds are essential deep-sea structural habitats that provide important services for the ecosystem. These large sponge aggregations are dominated by demosponges of the genus Geodia (order Tetractinellida, family Geodiidae). However, little is known about the basic biological features of these species, such as their life cycle and dispersal capabilities. Here, we surveyed five deep-sea species of Geodia from the North-Atlantic Ocean and studied their reproductive cycle and strategy using light and electron microscopy. The five species were oviparous and gonochoristic. Synchronous development was observed at individual and population level in most of the species. Oocytes had diameters ranging from 8 μm in previtellogenic stage to 103 μm in vitellogenic stage. At vitellogenic stages, oocytes had high content of lipid yolk entirely acquired by autosynthesis, with no participation of nurse cells. Intense vertical transmission of bacterial symbionts to the oocytes by phagocytosis through pseudopodia was observed, especially in late stages of oogenesis. The density of oocytes within the sponge tissue was on average 10 oocytes/mm ² across all species, higher than that of most temperate and tropical oviparous species studied elsewhere. Spermatic cysts were widespread over the tissue during early stages, or fused in larger cysts, around the canals in later stages, and occupying between 1.5 and 12% of the tissue in males. The reproductive season spanned similar periods for all Geodia spp.: from late spring to early autumn. During the reproductive peak of each species, between 60 and 90% of the population was engaged in reproduction for most species. Given the present hazards that threaten the boreo-arctic tetractinellid sponge grounds, it becomes crucial to understand the processes behind the maintenance and regeneration of populations of keystone deep-sea species in order to predict the magnitude of human impacts and estimate their ability to recover. The information provided in this study will be useful for developing adequate conservation strategies for these vulnerable deep-sea habitats.
Ellen L. Kenchington
added 3 research items
The Scotian Shelf harbors unique aggregations of the glass sponge Vazella pourtalesii that provides an important habitat for benthic and pelagic fauna. Recent studies have shown that these sponge grounds have persisted in the face of strong inter-annual and multi-decadal variability in temperature and salinity. However, little is known of these environmental characteristics on hourly-seasonal time scales. This study presents the first hydrodynamic observations and associated (food) particle supply mechanisms for the Vazella sponge grounds, highlighting the influence of natural variability in environmental conditions on sponge growth and resilience. Near-bottom environmental conditions were characterized by high temporal resolution data collected with a benthic lander, deployed during a period of 10 months in the Sambro Bank Sponge Conservation Area. The lander was equipped with temperature and oxygen sensors, a current meter, a sediment trap and a video camera. In addition, water column profiles of temperature and salinity were collected in an array across the sponge grounds from high to lower sponge presence probability. Over the course of the lander deployment, temperature fluctuated between 8.8–12°C with an average of 10.6 ± 0.4°C. Dissolved oxygen concentration was on average 6.3 mg l –1 , and near-bottom current speed was on average 0.12 m s –1 , with peaks up to 0.47 m s –1 . Semi-diurnal tidal currents promoted constant resuspension of particulate matter in the benthic boundary layer. Surface storm events episodically caused extremely turbid conditions on the seafloor that persisted for several days, with particles being resuspended to more than 13 m above the seabed. The carbon flux in the near-bottom sediment trap peaked during storm events and also after a spring bloom in April, when fresh phytodetritus was observed in the bottom boundary layer. While resuspension events can represent a major stressor for sponges, limiting their filtration capability and remobilizing them, episodes of strong currents and lateral particle transport likely play an important role in food supply and the replenishment of nutrients and oxygen. Our results contextualize human-induced threats such as bottom fishing and climate change by providing more knowledge of the natural environmental conditions under which sponge grounds persist.
Under regulation (EU) 2016/2336, the EU fleet will be banned from bottom fishing in all waters between 400 and 800m in depth, apart from within the existing fishing footprint. Within the fishing footprint, EU vessels will be prohibited from bottom fishing in any closed areas that might be introduced to protect VMEs. To meet these regulatory requirements, ICES was requested by the European Commission to provide “advice on the list of areas where VMEs are known to occur or are likely to occur and on the existing deep-sea fishing areas (ref. (EU)2016/2336)”. The ICES workshop WKEUVME was tasked to produce the technical evidence base for producing a set of regulatory area options, building on 2019 work (Technical Service and WKREG workshop), as well as previous ICES advice (ICES 2018a) and technical services (ICES 2018b). The work drew upon the most recent fishing activity and vulnerable marine ecosystem (VME) distribution data at ICES, which has been quality assured following the respective annual ICES data calls for VMS/logbook (link) and VMEs (link). The assessment procedure herein is fully documented, with the respective scripts to run the assessment available on an open source platform (WKEUVME GitHub site). Two “assessment sheets” with respective regulatory area options for two larger ecoregions (Bay of Biscay and Iberian Coast, and the Celtic Seas) were produced. These assessment sheets served as the basis for dissemination documents for managers – stakeholders meeting of WKEUVME in September 2020, and could be incorporated into their respective annual ICES Ecosystem and Fisheries Overviews in future. There are also strong links to shallower water assessment procedures developed by WGFBIT (Working Group on Fisheries Benthic Impact and Trade-offs) that have been developed for the ICES Ecosystem Overview advice in the context of Descriptor 6 seafloor integrity of the EC’s marine strategy framework directive (MSFD). WKEUVME used a data-driven approach to provide management options for this request. Two broad scenarios were provided, each with two options. For each option a set of rules was defined for producing the outcomes. The first scenario defined VME closure polygons without any modification by known fishing activity. The first option under this scenario focused on VME habitats and areas with a High or Medium VME Index score (a multi-criteria assessment method developed by WGDEC). The second option included areas identified in option 1 and added in areas where four types of VME elements were present (areas where VMEs are likely to occur: seamounts, banks, coral mounds, and mud volcanoes); allowing managers to choose the level of precaution they wish to apply in protecting VMEs. The second scenario identified areas where the fishing footprint overlapped with VMEs and then used VME biomass/fishing intensity relationships to identify a threshold (swept-area ratio (SAR) < 0.43) for areas where effort was low and unlikely to have caused Significant Adverse Impacts to the VMEs (at C-square resolution). Two options for closing areas under this scenario were presented: the first where VME habitats and areas with a High or Medium VME Index score (irrespective of fishing effort) and only Low VME Index score with low fishing effort were closed; the other where all areas of VME presence (habitats and Low, Medium and High VME Index values) were closed, but only in areas of low fishing effort, on the basis that any VME habitat in heavily fished C-squares would be degraded. To allow managers to evaluate the impact that closing these areas might have on different fishing métiers, and the trade-offs with protection of VMEs, WKEUVME tabulated fisheries data summarizing the percent of the fishing activity occurring within the 400-800 m depth band, relative to the EEZ of the relevant countries in each ecoregion. Further, WKEUVME used the percentiles of fishing effort (SAR) to map core fishing grounds both in the fishing footprint years (2009-2011) and in two, 4-year periods following. Summary statistics, graphs and maps were produced for ICES | WKEUVME 2020 | iii the assessments. Achieving a high level of VME protection in closures requires the creation of many closures (>100) with many small (~ 50 km2 ) and fewer larger closures (> 1000 km2 ). Full protection of all areas with a high probability of containing VMEs will affect 9-11% of the footprint of the fishery, while closure scenarios that avoid highly fished areas, and that are therefore less likely to support viable VMEs, would reduce this to around 3-9% of the footprint. Through this process a number of data sources that were not in the ICES VME Database were identified; e.g., data from the Northern Iberian Shelf, the Gettysburg Seamount on Gorringe Bank, the Tasyo mud volcano field and the Guadalquivir Diapiric Ridge in the Gulf of Cádiz. WKEUVME used this and other published information as supporting material for the assessments until such time as the data is submitted to ICES. A meeting with managers and stakeholders was subsequently held. This commenced with presentations describing the availability of fisheries and VME data and the way in which they were utilised by the Workshop, the rationale behind the scenarios and options that were selected, and the management implications of each option. The advantages and disadvantages of the regulatory options in terms of VME protection and the impact of potential closed areas on the fisheries were examined separately for the Celtic Sea Ecoregion and the Bay of Biscay and Iberian Coast Ecoregion, where stakeholders familiar with each region were able to express their preferences. The stakeholders present were supportive of the work done by ICES and felt that the 4 options were operationally feasible. Concerns were expressed over the data limitations, notably the occurrence of VMEs that are not in the ICES VME Database
Shallow-water sponges are often cited as being ‘climate change winners’ due to their resiliency against climate change effects compared to other benthic taxa. However, little is known of the impacts of climate change on deep-water sponges. The deep-water glass sponge Vazella pourtalesii is distributed off eastern North America, forming dense sponge grounds with enhanced biodiversity on the Scotian Shelf off Nova Scotia, Canada. While the strong natural environmental variability that characterizes these sponge grounds suggests this species is resilient to a changing environment, its physiological limitations remain unknown, and the impact of more persistent anthropogenic climate change on its distribution has never been assessed. We used Random Forest and generalized additive models to project the distribution of V. pourtalesii in the northwest Atlantic using environmental conditions simulated under moderate and worst-case CO2 emission scenarios. Under future (2046–2065) climate change, the suitable habitat of V. pourtalesii will increase up to 4 times its present-day size and shift into deeper waters and higher latitudes, particularly in its northern range where ocean warming will serve to improve the habitat surrounding this originally sub-tropical species. However, not all areas projected as suitable habitat in the future will realistically be populated,and the reduced likelihood of occurrence in its core habitat on the Scotian Shelf suggests that the existing Vazella sponge grounds may be negatively impacted. An effective monitoring programme will require tracking changes in the density and distribution of V. pourtalesii at the margins between core habitat and where losses and gains were projected.
Ellen L. Kenchington
added a research item
Novel 3-D passive particle tracking experiments were performed in the northwest Atlantic to elucidate connectivity among areas closed to protect vulnerable marine ecosystems. We examined (1) the degree of vertical movement of particles released at different depths and locations; (2) the location of potential source populations for the deep-sea taxa protected by the closures; and (3) the degree of functional connectivity. A long-term oceanographic dataset (EN4) was queried to characterize the temperature and salinity regimes in each of the closed areas as a basis for interpreting recently published climate change projections. Using the Parcels Lagrangian particle tracking framework and the BNAM hydrodynamic model, we found enhanced connectivity over previously developed 2-D models and unexpected, current-driven, strong (to a maximum of about 1340 m) downward displacement at depth (450, 1000 and 2250 m), with weaker upward displacement except for the release depth of 2250 m which showed upward movement of 955 m with a drift duration of 3 months. The current velocities create down-stream interdependence among closed areas and allow redundancy to develop in some of the areas of the network, with some of the larger areas also showing retention. Source populations for sponges in the upstream closure are likely in adjacent waters of the Canadian continental shelf. Collectively this information can be used to inform management decisions related to the size and placement of these closed areas, and vertical velocity surfaces have potential for use in species distribution modeling of benthic species and habitats.
Anna De Kluijver
added a research item
Sponges produce distinct fatty acids (FAs) that (potentially) can be used as chemotaxonomic and ecological biomarkers to study endosymbiont-host interactions and the functional ecology of sponges. Here, we present FA profiles of five common habitat-building deep-sea sponges (class Demospongiae, order Tetractinellida), which are classified as high microbial abundance (HMA) species. Geodia hentscheli, G. parva, G. atlantica, G. barretti , and Stelletta rhaphidiophora were collected from boreal and Arctic sponge grounds in the North-Atlantic Ocean. Bacterial FAs dominated in all five species and particularly isomeric mixtures of mid-chain branched FAs (MBFAs, 8- and 9-Me-C 16:0 and 10 and 11-Me-C 18:0 ) were found in high abundance (together ≥ 20% of total FAs) aside more common bacterial markers. In addition, the sponges produced long-chain linear, mid- and a(i)- branched unsaturated FAs (LCFAs) with a chain length of 24‒28 C atoms and had predominantly the typical Δ 5,9 unsaturation, although also Δ 9,19 and (yet undescribed) Δ 11,21 unsaturations were identified. G. parva and S. rhaphidiophora each produced distinct LCFAs, while G. atlantica, G. barretti , and G. hentscheli produced similar LCFAs, but in different ratios. The different bacterial precursors varied in carbon isotopic composition (δ ¹³ C), with MBFAs being more enriched compared to other bacterial (linear and a ( i )-branched) FAs. We propose biosynthetic pathways for different LCFAs from their bacterial precursors, that are consistent with small isotopic differences found in LCFAs. Indeed, FA profiles of deep-sea sponges can serve as chemotaxonomic markers and support the conception that sponges acquire building blocks from their endosymbiotic bacteria.
Anna De Kluijver
added a research item
Abstract Deep-sea sponges create hotspots of biodiversity and biological activity in the otherwise barren deep-sea. However, it remains elusive how sponge hosts and their microbial symbionts acquire and process food in these food-limited environments. Therefore, we traced the processing (i.e. assimilation and respiration) of 13C- and 15N-enriched dissolved organic matter (DOM) and bacteria by three dominant North Atlantic deep-sea sponges: the high microbial abundance (HMA) demosponge Geodia barretti, the low microbial abundance (LMA) demosponge Hymedesmia paupertas, and the LMA hexactinellid Vazella pourtalesii. We also assessed the assimilation of both food sources into sponge- and bacteria-specific phospholipid-derived fatty acid (PLFA) biomarkers. All sponges were capable of assimilating DOM as well as bacteria. However, processing of the two food sources differed considerably between the tested species: the DOM assimilation-to-respiration efficiency was highest for the HMA sponge, yet uptake rates were 4–5 times lower compared to LMA sponges. In contrast, bacteria were assimilated most efficiently and at the highest rate by the hexactinellid compared to the demosponges. Our results indicate that phylogeny and functional traits (e.g., abundance of microbial symbionts, morphology) influence food preferences and diet composition of sponges, which further helps to understand their role as key ecosystem engineers of deep-sea habitats.
Ellen L. Kenchington
added a research item
Biogeochemical cycling of silicon (Si), largely affected by biological drivers, is pivotal to the ecological functioning of the ocean. Most knowledge regarding biological utilization of Si derives from research on photo-trophic organisms circumscribed to the photic ocean (i.e., diatoms). Utilization of Si in the aphotic ocean, where heterotrophic silicifiers become relevant Si users, remains poorly investigated. Here we quantify the flux rates and stocks characterizing Si cycling across dense aggregations of the hexactinellid sponge Vazella pourtalesii established in the aphotic zone of the central Scotian Shelf, Nova Scotia, Canada. Although individual rates of silicic acid consumption were low compared to other sponge species and diatoms, the large abundance of individuals (6.5 million) over the extension of these sponge grounds (2105 km 2) leads to massive annual silicic acid consumption, invested in producing their siliceous skeletons of biogenic silica. This sponge activity accumulates large biogenic silica stocks both in the living population and in the sediments. Skeletal pieces in sediment revealed that a good portion of biogenic silica deposited to the bottom after sponge death recycles as silicic acid before being permanently buried. This biogenic silica-silicic acid turnover, facilitated by an unconventional silicification pattern that favors delamination and dissolution of V. pourtalesii spicules, causes silicic acid enrichment at oceanographic dimensions in the bottom water of the central Scotian Shelf. Silicic acid efflux from the bottom sustains a feedback mechanism that fulfills sponge needs for silicic acid and facilitates the persistence of sponge aggregations in the long term.
Paco Cárdenas
added a research item
All animals are capable of undergoing gametogenesis. The ability of forming haploid cells from diploid cells through meiosis and recombination appeared early in eukaryotes, whereas further gamete differentiation is mostly a metazoan signature. Morphologically, the gametogenic process presents many similarities across animal taxa, but little is known about its conservation at the molecular level. Porifera are the earliest divergent animals and therefore are an ideal phylum to understand evolution of the gametogenic toolkits. Although sponge gametogenesis is well known at the histological level, the molecular toolkits for gamete production are largely unknown. Our goal was to identify the genes and their expression levels which regulate oogenesis and spermatogenesis in five gonochoristic and oviparous species of the genus Geodia, using both RNAseq and proteomic analyses. In the early stages of both female and male gametogenesis, genes involved in germ cell fate and cell-renewal were upregulated. Then, molecular signals involved in retinoic acid pathway could trigger the meiotic processes. During later stages of oogenesis, female sponges expressed genes involved in cell growth, vitellogenesis, and extracellular matrix reassembly, which are conserved elements of oocyte maturation in Metazoa. Likewise, in spermatogenesis, genes regulating the whole meiotic cycle, chromatin compaction, and flagellum axoneme formation, that are common across Metazoa were overexpressed in the sponges. Finally, molecular signals possibly related to sperm capacitation were identified during late stages of spermatogenesis for the first time in Porifera. In conclusion, the activated molecular toolkit during gametogenesis in sponges was remarkably similar to that deployed during gametogenesis in vertebrates.
Beate Slaby
added a research item
Establishment of adequate conservation areas represents a challenging but crucial task in the conservation of genetic diversity and biological variability. Anthropogenic pressures on marine ecosystems and organisms are steadily increasing. Whether and to what extent these pressures influence marine genetic biodiversity is only starting to be revealed. Using 16S rRNA gene amplicon sequencing, we analysed the microbial community structure of 33 individuals of the habitat-forming glass sponge Vazella pourtalesii, as well as reference seawater, sediment, and biofilm samples. We assessed how two anthropogenic impacts, i.e. habitat destruction by trawling and artificial substrate provision (moorings made of composite plastic), correspond with in situ V. pourtalesii microbiome variability. In addition, we evaluated the role of two bottom fishery closures in preserving sponge-associated microbial diversity on the Scotian Shelf, Canada. Our results illustrate that V. pourtalesii sponges collected from protected sites within fishery closures contained distinct and taxonomically largely novel microbial communities. At the trawled site we recorded significant quantitative differences in distinct microbial phyla, such as a reduction in Nitrospinae in the four sponges from this site and the environmental references. Individuals of V. pourtalesii growing on the mooring were significantly enriched in Bacteroidetes, Verrucomicrobia and Cyanobacteria in comparison to sponge individuals growing on the natural seabed. Due to a concomitant enrichment of these taxa in the mooring biofilm, we propose that biofilms on artificial substrates may ‘prime’ sponge-associated microbial communities when small sponges settle on such substrates. These observations likely have relevant management implications when considering the increase of artificial substrates in the marine environment, e.g., marine litter, off-shore wind parks, and petroleum platforms.
Beate Slaby
added a research item
We investigated the microbial community of V. pourtalesii that forms globally unique, monospecific sponge grounds under low-oxygen conditions on the Scotian Shelf, where it plays a key role in its vulnerable ecosystem. The microbial community was found to be concentrated within biomass patches and is dominated by small cells (<1 μm). MAG analyses showed consistently small genome sizes and low GC contents, which is unusual compared to known sponge symbionts. These properties, as well as the (facultatively) anaerobic metabolism and a high degree of interdependence between the dominant symbionts regarding amino acid and vitamin synthesis, are likely adaptations to the unique conditions within the syncytial tissue of their hexactinellid host and the low-oxygen environment.
Pilar Ríos
added a research item
Deep-sea sponge-dominated communities are complex habitats considered hotspots of biodiversity and ecosystem functioning. They are classified as Vulnerable Marine Ecosystem and are listed as threatened or declining as a result of anthropogenic activities. Yet, studies into the distribution, community structure and composition of these habitats are scarce, hampering the development of appropriate management measures to ensure their conservation. In this study we describe a diverse benthic community, dominated by a lithistid sponge, found in two geomorphological features of important conservation status —Le Danois Bank and El Corbiro Canyon— of the Cantabrian Sea. Based on the analyses of visual transects using a photogrammetric towed vehicle and samples collected by rock dredge, we characterize the habitat and the associated community in detail. This deep-sea sponge aggregation was found on bedrock. It is dominated by one lithistid sponge, Neoschrammeniella aff. bowerbankii (0.2 ind./m2) and further composed of various sponge species as well as of other benthic invertebrates such as cnidarians, bryozoans and crustaceans. Using a non-invasive methodology (SfM – Structure from Motion) and empirical relationships of individuals size and biomass/volume obtained in laboratory for N. aff. bowerbankii, we were able to estimate a total biomass of 41 kg and volume of 39 l of this species in the surveyed area. This approach allows a fine tune methodology for estimating biomass and volume by image-based-observed area avoiding destructive techniques for this species.
Ellen L. Kenchington
added a research item
The biological utilization of dissolved silicon (DSi) influences ocean ecology and biogeochemistry. In the deep sea, hexactinellid sponges are major DSi consumers that remain poorly understood. Their DSi consumption departs from the Michaelis-Menten kinetics of shallow-water demosponges and appears particularly maladapted to incorporating DSi from the modest concentrations typical of the modern ocean. Why did sponges not adapt to the shrinking DSi availability that followed diatom expansion some 100 to 65 million years ago? We propose that sponges incorporate DSi combining passive (aquaglyceroporins) and active (ArsB) transporters, while only active transporters (SITs) operate in diatoms and choanoflagellates. Evolution of greater silicon transport efficiency appears constrained by the additional role of aquaglyceroporins in transporting essential metalloids other than silicon. We discuss the possibility that lower energy costs may have driven replacement of ancestral SITs by less efficient aquaglyceroporins, and discuss the functional implications of conservation of aquaglyceroporin-mediated DSi utilization in vertebrates.
Heidi K Meyer
added a research item
The Sognefjord is the longest (205 km) and deepest (1308 m) fjord in Norway, and the second-longest in the world. Coast-fjord exchange in Sognefjord is limited by a seaward sill at 170 m water depth, which causes a clear stratification between water masses as the dense oxygen-poor basin water mixes slowly with the well-oxygenated water directly above from the coastal ocean. Due to the homogeneity and limited variability in the deep-water, the deep slopes of Sognefjord represent the ideal setting to study how abiotic factors influence the deep-water benthic community structure. During the summer of 2017, two remotely operated vehicle (ROV) video transects were performed to compare the megabenthic community behind the sill (water depth: 1230 to 55 m; transect length: 1.39 km; distance from sill: ∼17 km) and within the central fjord (water depth: 1155-85 m; transect length: 2.43 km; distance from sill: ∼79 km). Accompanying conductivity-temperature-depth (CTD) deployments were made to measure the in situ abiotic factors and nutrient concentrations at each transect location, while the substrate characteristics (percent cover of soft and hard exposed substrate) were documented from the video footage. Here, Sognefjord's megabenthic community composition, distribution, and species richness were analyzed in relation to abiotic factors (e.g., depth, salinity, dissolved oxygen, chlorophyll a concentration, and percent cover of hard and soft substrata) within the fjord. Basin communities were homogeneous and characterized by sponges, echinoderms, and crustaceans, whereas the shallower regions were dominated by mobile scavengers. Contrary to other fjord-based studies, species richness and diversity were stable in the fjord basin and decreased with proximity to the sill, decreasing water depth, and at the boundary between intermediate and basin water. The findings demonstrate that highly stratified fjords support stable communities in their basins; however, further research is needed to investigate the influence water mass dynamics have on silled-fjord megafauna communities.
Beate Slaby
added a research item
Few studies have thus far explored the microbiomes of glass sponges (Hexactinellida). The present study seeks to elucidate the composition of the microbiota associated with the glass sponge Vazella pourtalesii and the functional strategies of the main symbionts. We combined microscopic approaches with metagenome-guided microbial genome reconstruction and amplicon community profiling towards this goal. Microscopic imaging revealed that the host and microbial cells appeared within dense biomass patches that are presumably syncytial tissue aggregates. Based on abundances in amplicon libraries and metagenomic data, SAR324 bacteria, Crenarchaeota, Patescibacteria and Nanoarchaeota were identified as abundant members of the V. pourtalesii microbiome and their genomic potentials were thus analyzed in detail. A general pattern emerged in that the V. pourtalesii symbionts had very small genome sizes in the range of 0.5-2.2 Mb and low GC contents, even below those of seawater relatives. Based on functional analyses of metagenome-assembled genomes (MAGs), we propose two major microbial strategies: the “givers”, namely Crenarchaeota and SAR324, heterotrophs and facultative anaerobes, produce and partly secrete all required amino acids and vitamins. The “takers”, Nanoarchaeota and Patescibacteria, are anaerobes with reduced genomes that tap into the microbial community for resources, e.g., lipids and DNA, likely using pili-like structures. We posit that the existence of microbial cells in sponge syncytia together with the low-oxygen conditions in the seawater environment are factors that shape the unique compositional and functional properties of the microbial community associated with V. pourtalesii . Importance We investigated the microbial community of V. pourtalesii that forms globally unique, monospecific sponge grounds under low-oxygen conditions on the Scotian Shelf, where it plays a key role for its vulnerable ecosystem. The microbial community was found to be concentrated within biomass patches and is dominated by small cells (<1 μm). MAG analyses showed consistently small genome sizes and low GC contents, which is unusual in comparison to known sponge symbionts. These properties as well as the (facultatively) anaerobic metabolism and a high degree of interdependence between the dominant symbionts regarding amino acid and vitamin synthesis are likely adaptations to the unique conditions within the syncytial tissue of their hexactinellid host and the low-oxygen environment.
Beate Slaby
added a research item
ABSTRACT Establishment of adequate conservation areas represents a challenging but crucial task in the conservation of genetic diversity and biological variability. Anthropogenic pressures on marine ecosystems and organisms are steadily increasing. Whether and to what extent these pressures influence marine genetic biodiversity is only starting to be revealed. Using 16S rRNA gene amplicon sequencing, we analysed the microbial community structure of 33 individuals of the habitat-forming glass sponge Vazella pourtalesii, as well as reference seawater, sediment, and biofilm samples. We assessed how two anthropogenic impacts, i.e. habitat destruction by trawling and artificial substrate provision (moorings made of composite plastic), correspond with in situ V. pourtalesii microbiome variability. In addition, we evaluated the role of two bottom fishery closures in preserving sponge-associated microbial diversity on the Scotian Shelf, Canada. Our results illustrate that V. pourtalesii sponges collected from pristine sites within fishery closures contained distinct and taxonomically largely novel microbial communities. At the trawled site we recorded significant quantitative differences in distinct microbial phyla, such as a reduction in Nitrospinae in sponges and environmental references. Individuals of V. pourtalesii growing on the mooring were significantly enriched in Bacteroidetes, Verrucomicrobia and Cyanobacteria in comparison to sponge individuals growing on the natural seabed. Due to a concomitant enrichment of these taxa in the mooring biofilm, we propose that biofilms on artificial substrates may ‘prime’ sponge-associated microbial communities when small sponges settle on such substrates. These observations likely have relevant management implications when considering the increase of artificial substrates in the marine environment, e.g., marine litter, off-shore wind parks, and petroleum platforms.
Pilar Ríos
added a research item
Background Lithistid demosponges, also known as rock sponges, are a polyphyletic group of sponges which are widely distributed. In the Northeast Atlantic (NEA), 17 species are known and the current knowledge on their distribution is mainly restricted to the Macaronesian islands. In the Mediterranean Sea, 14 species are recorded and generally found in marine caves. Methods Lithistids were sampled in nine NEA seamounts during the scientific expeditions Seamount 1 (1987) and Seamount 2 (1993) organized by the MNHN of Paris. Collected specimens were identified through the analyses of external and internal morphological characters using light and scanning electron microscopy, and compared with material from various museum collections as well as literature records. Results A total of 68 specimens were analysed and attributed to 17 species across two orders, seven families, and seven genera, representing new records of distribution. Ten of these species are new to science, viz. Neoschrammeniella inaequalis sp. nov., N. piserai sp. nov., N. pomponiae sp. nov., Discodermia arbor sp. nov., D. kellyae sp. nov., Macandrewia schusterae sp. nov., M. minima sp. nov., Exsuperantia levii sp. nov., Leiodermatium tuba sp. nov. and Siphonidium elongatus sp. nov., and are here described and illustrated. New bathymetric records were also found for D. ramifera , D. verrucosa and M. robusta . The Meteor seamount group has a higher species richness (15 species) compared to the Lusitanian seamount group (six species). The majority of the species had their distribution restricted to one seamount, and ten are only known from a single locality, but this can be a result of sample bias. Discussion The number of species shared between the seamounts and the Macaronesian islands is very reduced. The same pattern repeats between the NEA and Mediterranean Sea. This study demonstrates that NEA seamounts are ecosystems with a higher diversity of lithistids than previously thought, increasing the number of lithistids known to occur in the NEA and Mediterranean Sea from 26 to 36 species.
Ellen L. Kenchington
added a research item
The ecological diversity of benthic invertebrates from bottom trawl surveys was mapped for the Flemish Cap, a plateau of ~200 km radius in the northwest Atlantic. Species density (SpD), the exponential Shannon diversity index (e H′) and Heip's index of evenness (E ~ ') were measured at different spatial scales. Continuous surfaces of each were created to 2000 m depth using predictive distribution models based on random forest (RF) algorithms. When fishing effort was included as an independent variable in the RF models, it was the most important predictor of sample SpD but unimportant in predicting e H′ and only a minor predictor of E ~ '. In the absence of a historical baseline, we used a novel approach to evaluate spatial impacts of fishing on diversity by simulating and comparing spatial SpD prediction surfaces using response data associated with different levels of fishing effort. Although it is not possible to fully evaluate the precise nature of the impact of fishing on the ecological diversity, our models have identified Sackville Spur, Flemish Pass and south of Flemish Cap as the areas of greatest impact. Combining minimum bottom salinity, annual primary production range, fishing effort and biomass of sponges and small gorgonian corals, resulted in the best performing generalized additive model, explaining 73% of the total variance in SpD. Although current closures to protect vulnerable marine ecosystems from the adverse impacts of bottom fishing activities protect an important part of the ecological diversity associated with the deeper communities, unique and representative habitats on top of the Cap remain unprotected.
Ellen L. Kenchington
added a research item
Aim To characterize the functional diversity and selected ecological functions of marine epibenthic invertebrate communities at the ecosystem scale and to evaluate the relative contributions of environmental filtering, including bottom‐contact fishing, and competitive interactions to benthic community assembly. Location Flemish Cap, an ecosystem production unit and fishing bank in the high seas of the north‐west Atlantic Ocean. Methods Through the use of Hierarchical Modelling of Species Communities (HMSC), we have explored seven community response traits to the environment applied to 105 epibenthic species and evaluated the influence of such traits on the community assembly processes. Assumed bioturbation, nutrient cycling and habitat provision functions, linked to individual or a combination of biological traits, were mapped using random forest modelling. Results Functional richness within benthic communities reached an asymptote for trawl sets with roughly more than 30 species. Assemblages on top of the Flemish Cap (<500 m depth) were characterized by higher biomass of small‐ and medium‐sized species with short life spans, whereas large species with longer life spans and broadcast spawners were dominant in the deeper assemblages (500–1,500 m depth). The amount of variation explained by the species’ responses to the covariates mediated by the traits was relatively high (25%) indicating their relevance to community assembly. Community‐weighted mean trait values changed with depth and physical oceanographic variables, indicating that environmental filtering was occurring. Interspecific interactions, as inferred from the random effect at the sample level, accounted for 16.3% of the variance in the model, while fishing effort explained only 5.2% of the variance but conferred strong negative impacts for most species. Main conclusions Our results suggest that while bottom‐contact fishing impacts have an effect on functional diversity, changes to the physical oceanography of the system are likely to have more profound impacts. The maps of benthic functioning can aid assessments of ecosystem impacts of fishing.
Ellen L. Kenchington
added a research item
Lagrangian particle tracking models are considered an important tool for assessing connectivity in the deep sea. A number of user interfaces are available to assess oceanic structural connectivity. These use currents produced by state-of-the-art ocean models, and can be used to run forward/hindcast simulations, habitat connectivity calculations, comparison of physical circulation models, etc. We compared simulation outputs from two particle tracking packages, WebDrogue v.0.7 and the Parcels framework version 2.1, the former having been previously published in a study investigating connectivity patterns among closed areas in the NAFO Regulatory Area. We further tested a combination of parameters used by Parcels (number of particles, particle spacing, time step, random walk) to determine optimal values for future applications. Parcels identified more connectivity than WebDrogue with differences attributed to higher current velocities in the underlying ocean model, although drift pathways were generally similar in both.
Ellen L. Kenchington
added a research item
In support of the 2020 NAFO review of the closed areas to protect vulnerable marine ecosystems (VMEs) in the NAFO Regulatory Area, kernel density analyses (KDE) of Large-sized Sponges, Sea Pens, Small and Large Gorgonian Corals, Erect Bryozoans, Sea Squirts (Boltenia ovifera), and Black Corals were undertaken using all available research vessel survey data (1995 – 2019). This is the first KDE analysis of black corals for this area. KDE polygons equating to VMEs were overlain on binary outputs of predicted suitable versus unsuitable habitat from species distribution models (SDMs) for each taxon where available, and for sponges and large gorgonian corals, polygons were modified to areas of predicted suitable habitat consistent with previous practices. New SDMs were prepared for Erect Bryozoans and Sea Squirts (Boltenia ovifera). For Tube-dwelling (Cerianthid) Anemones and Sea Lilies (Crinoids), updated distribution maps were provided, drawing on data from research vessel trawl surveys, NEREIDA rock dredge samples and NEREIDA underwater imagery. The effectiveness of the closed areas was for the first time assessed by examining the proportion of VME area and biomass protected for each VME indicator type. The results of these analyses were compared with those previously conducted in 2013 and reviewed by the NAFO Working Group on Ecosystem Science and Assessment (WGESA) at its 12th meeting in November 2019.
Ellen L. Kenchington
added a research item
Sponges (phylum Porifera) are benthic filter feeding animals that play an important role in nutrient cycling and habitat provision in the deep sea. Sponges collected between 2010 and 2014 during annual multispecies trawl surveys conducted by Fisheries and Oceans Canada in Baffin Bay, Davis Strait and portions of Hudson Strait were taxonomically examined. In total ~2500 specimens were identified, comprising ~100 known sponge taxa. Sponges from the order Poecilosclerida comprised nearly half of the identified species. Sponges from the poescilosclerid families Coelosphaeridae, Crellidae, Dendoricellidae, Myxillidae and Tedaniidae are described in previous reports. This report adds descriptions of eight sponge species from three poescilosclerid families: Microcionidae, Acarnidae and Esperiopsidae (class Demospongiae, subclass Heteroscleromorpha, order Poecilosclerida). Described species include Artemisina lundbecki, Artemisina arcigera, and Clathria (Clathria) barleei from the family Microcionidae, Iophon piceum and Iophon koltuni from the family Acarnidae, and Esperiopsis villosa, Esperiopsis sp. 1, and Semisuberites cf. cribrosa from the family Esperiopsidae. Descriptions include physical description of the sponges, descriptions and dimensions of their spicules, and taxonomic discussion.
Paco Cárdenas
added a research item
Nettersheim et al.propose that unicellular Rhizaria are the likely biological source of the C₃₀ steroidal hydrocarbons found abundantly in Neoproterozoic–Cambrian sedimentary rocks. Their hypothesis challenges earlier research arguing that 24-isopropylcholestane (24-ipc) and 26-methylstigmastane (26-mes) are produced by demosponges and, therefore, early animal biomarkers2. Fundamental problems beset the new steroid biomarker data and its interpretation.
Emyr Martyn Roberts
added a research item
Deep-sea sponge grounds are important habitats that provide several ecosystem services, yet relatively little is known about their distribution and ecology. While most surveys have focused on the broad-scale distribution patterns of sponge grounds (100s–1000s m), only rarely have the finer-scale (<10 m) spatial distribution patterns of the primary organisms been studied. In this study, the autonomous underwater vehicle (AUV) Hugin 1000 was used to map an area of an arctic sponge ground located on the summit of the Schulz Bank (Arctic Mid-Ocean Ridge), with the aim of detecting small-scale spatial patterns produced by the dominant megafauna. Using low-light cameras to construct a photomosaic comprising of 9,953 images and a virtual quadrat spatial sampling approach, density hotspots of the most prominent megafauna were visualized. The primary megafauna detected were demosponges, hexactinellids, ascidians, cnidarians, echinoderms, and demersal fish species. Most megafauna, like the primary structure-forming sponge species Geodia parva and Stelletta rhaphidiophora, were distributed evenly throughout the sample area, though species like Lissodendoryx (Lissodendoryx) complicata and Gersemia rubiformis displayed clear fine-scale spatial preferences. The three demersal fish species, Macrourus berglax, Reinhardtius hippoglossoides, and Amblyraja hyperborea, were uniformly distributed throughout the sample area. Based on the presence of skate egg cases and juveniles within many images, it is likely that the site is being used as a nursery ground for A. hyperborea. This study demonstrates the potential of using AUVs to detect fine-scale spatial patterns of the structure-forming sponges and demersal fish species. The use of AUVs for deep-water benthic surveys can help visualize how fauna (e.g. fish) utilise deep-sea habitats, and act as a tool for quantifying individuals through relatively unbiased means (e.g. pre-programmed track, no sampling). Such information is crucial for future conservation and management efforts.
Christopher Kim Pham
added a research item
Deep-sea sponge grounds are vulnerable marine ecosystems, which through their benthic-pelagic coupling of nutrients, are of functional relevance to the deep-sea realm. The impact of fishing bycatch is here evaluated for the first time at a bathyal, sponge-dominated ecosystem in the high seas managed by the Northwest Atlantic Fisheries Organization. Sponge biomass surfaces created from research survey data using both random forest modeling and a gridded surface revealed 231,140 t of sponges in the area. About 65% of that biomass was protected by current fisheries closures. However, projections of trawling tracks estimated that the sponge biomass within them would be wiped out in just 1 year by the current level of fishing activity if directed on the sponges. Because these sponges filter 56,143 ± 15,047 million litres of seawater daily, consume 63.11 ± 11.83 t of organic carbon through respiration, and affect the turnover of several nitrogen nutrients, their removal would likely affect the delicate ecological equilibrium of the deep-sea benthic ecosystem. We estimated that, on Flemish Cap, the economic value associated with seawater filtration by the sponges is nearly double the market value of the fish catch. Hence, fishery closures are essential to reach sponge conservation goals as economic drivers cannot be relied upon.
Paco Cárdenas
added a research item
The blending of synthetic chemistry with biosynthetic processes provides a powerful approach to synthesis. Biosynthetic halogenation and synthetic cross‐coupling have great potential to be used together, for small molecule generation, access to natural product analogues and as a tool for chemical biology. However to enable enhanced generality of this approach, further synthetic tools are needed. Though considerable research has been invested in the diversification of phenylalanine and tyrosine, functionalisation of tryptophans thorough cross‐coupling has been largely neglected. Tryptophan is a key residue in many biologically active natural products and peptides; in proteins it is key to fluorescence, and dominates protein folding. To this end, we have explored the Heck cross‐coupling of halo‐indoles and halo‐tryptophans in water, showing broad reaction scope. We have demonstrated the ability to use this methodology in the functionalisation of a new to nature brominated antibiotic (bromo‐pacidamycin), as well as a marine sponge metabolite, barettin.
Paco Cárdenas
added a research item
Blending synthetic biology and synthetic chemistry represents a powerful approach to diversity complex molecules. To further enable this, compatible synthetic tools are needed. We report the first Buchwald Hartwig amination reactions with unprotected halo-tryptophans under aqueous conditions and demonstrate this methodology is applicable also to the modification of unprotected tripeptides and the natural product barettin. Tryptophan is an essential amino acid, abundant within peptides and proteins, and central to their fluorescence, folding and structure; 1 it is also an important component in many bioactive natural products including non-ribosomal peptides e.g., vancomycin, and a precursor to indole alkaloids e.g., vinblastine and vincristine. 2 Modulation of tryptophan affords the potential to tune fluorescence, conformation and activity of these (bio)molecules. 3 Although there has been significant research exploring the cross-coupling chemistry of nucleosides and the aromatic amino acid phenylalanine, both in their free state or as components of larger systems, the cross-coupling of halotryptophan has seemingly received little attention. Methodology now exists for the modification of halotryptophans, by Sonogashira 4 and Suzuki-Miyaura 5,6 but, to the best of our knowledge, the utilisation of Buchwald Hartwig amination (BHA) of halotryptophans and their derivatives remains unexplored. Whilst BHA conditions have been applied to a wide range of aromatic species including indoles and 6-bromoquinolone (Scheme 1A and B), 7,8 to the best of our knowledge there is no literature precedent for its use in unprotected biomolecule functionalisation. Herein we report the application of aqueous BHA coupling to 5-bromoindole (Scheme 1C) and unprotected halotryptophans with a range of substituted aniline coupling partners (Scheme 1D). We then present the BHA derivatisation of tripeptides and the natural product barettin (Scheme 1E and F). We set out to explore the feasibility of developing aqueous conditions for BHA coupling of halotryptophans, which may be readily accessed through a simple one-step biotransformation of indoles using tryptophan synthase 9 or through a 4-5 step chemical synthesis. 10