Glass sponge grounds on the Scotian Shelf and their associated biodiversity

Hawkes, Nickolas James; Korabik, Michelle; Beazley, Lindsay; Rapp, Hans Tore; Xavier, Joana R.; Kenchington, Ellen

doi:10.3354/meps12903

Cited by 56 publications

(67 citation statements)

References 43 publications

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“…They can be mono- to multispecific with a single or various sponge species dominating the benthic community, respectively. In sponge ground ecosystems, these basal animals play a crucial role in the provision of habitat, adding structural complexity to the environment and thereby attracting other organisms, ultimately causing an enhancement of local biodiversity ( 3 – 5 ).…”

Section: Introductionmentioning

confidence: 99%

Microbial Strategies for Survival in the Glass Sponge Vazella pourtalesii

et al. 2020

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Few studies have 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 toward 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; thus, their genomic potentials were analyzed in detail. A general pattern emerged in that the V. pourtalesii symbionts had very small genome sizes, in the range of 0.5 to 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 pilus-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 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.

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Section: Introductionmentioning

confidence: 99%

Microbial Strategies for Survival in the Glass Sponge Vazella pourtalesii

et al. 2020

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“…Benthic invertebrates provide a multiplicity of ecosystem functions and services in the marine environment. They represent a key link between benthic and pelagic ecosystems (Griffiths et al, ) facilitating nutrient cycling (Kutti, Bannister, & Fosså, ; Perea‐Blázquez, Davy, & Bell, ), and through their physical structure, some enhance habitat complexity increasing biodiversity (Beazley, Kenchington, Murillo, & Sacau, ; Beazley, Kenchington, Yashayaev, & Murillo, ; Hawkes et al, ), provide nursery areas (Aldrich & Lu, ; Etnoyer & Warrenchuk, ) and modify biochemical regimes (Kaufmann & Smith, ; Soltwedel & Vopel, ). Some benthic invertebrates are also an important food source for fish and marine mammals (González, Román, & Paz, ; Oliver, Slattery, O’Connor, & Lowry, ) and can be active predators themselves (e.g., sea stars, crabs, gastropods).…”

Section: Introductionmentioning

confidence: 99%

Marine epibenthic functional diversity on Flemish Cap (north‐west Atlantic)—Identifying trait responses to the environment and mapping ecosystem functions

Murillo

Weigel

Marmen

et al. 2020

Diversity and Distributions

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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.

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“…Food energy arrives in the form of detrital inputs (Smith et al, 2001(Smith et al, , 2008Bernardino et al, 2010), and the long-term energetic demand of benthic communities outstrips the supply of surface water production (Smith and Kaufmann, 1999). Despite the general rule of food limitation in deep-water systems, large productive ecosystems formed by foundation species, such as cold-water coral and sponge reefs, exist throughout the world (Carlier et al, 2009;Beazley et al, 2013;Maldonado et al, 2016;Hawkes et al, 2019). For example, glass sponge reefs are a deep-water ecosystem in the shelf waters of the Northeast Pacific, from the Canada-Alaska border south through the Salish Sea (Stone et al, 2014;Dunham et al, 2018a;Shaw et al, 2018).…”

Section: Introductionmentioning

confidence: 99%