DSpace Collection:http://hdl.handle.net/10174/142872024-03-29T00:27:48Z2024-03-29T00:27:48ZVarying response of bacteria and nematodes to environmental conditions of Sado estuary – implications for estuarine benthic food webs.Vieira, S.Vicente, C.Neves, J.Martins, M.Adão, H.Sroczynska, K.http://hdl.handle.net/10174/339142023-02-07T11:07:55Z2022-12-05T00:00:00ZTitle: Varying response of bacteria and nematodes to environmental conditions of Sado estuary – implications for estuarine benthic food webs.
Authors: Vieira, S.; Vicente, C.; Neves, J.; Martins, M.; Adão, H.; Sroczynska, K.
Abstract: Sediment microbiome and benthic nematodes are indispensable in regulating benthic estuarine ecosystems and knowledge on their distribution patterns is essential for understanding of benthic food webs dynamics. However, simultaneous ecological analysis of bacteria and nematodes communities are seldom made, whereas the question if there exist a congruence between both taxonomic groups in their responses to different ecological conditions is largely unresolved. The main goal of this work was to analyze spatial and temporal distributional patterns of bacteria and nematodes in response to different environmental conditions in Sado Estuary, SW Portugal and further establish a link between these results and estuarine food web data generated using stable isotopes. All samples were collected at two distinct sampling occasions (autumn 2019 and Summer 2020) from three contrasting sites with varying sediment characteristics and human impact degrees. The sediment biogeochemical properties and the composition of bacterial and nematode communities were determined. To analyze bacterial communities, total DNA from sediment was extracted using DNeasy Power Soil kit® (MOBIO, Qiagen) and processed for Illumina MiSeq platform sequencing targeting the V3 and V4 region of 16S rRNA gene. Nematode assemblages were morphologically identified until genera level. All bacterial communities were highly diverse (α-diversity) presenting high β-diversity among the three sites and across two seasons. The distributional patterns presented a close concordance with ecological conditions associated to each site and season. Whereas nematode assemblages yielded a less clear distributional patterns suggesting that their response is rather driven by the within site specific factors. These results will be crossed with estuarine food web data generated through stable isotopes to resolve how distribution patterns of bacteria and nematode communities are reflected in the architecture of the estuarine benthic food webs.2022-12-05T00:00:00ZNematode communities from a natural oil seep off Svalbard.Balsa, J.Argentino, C.Riva, F.Adão, H.Panieri, G.Ramalho, S.P.http://hdl.handle.net/10174/339112023-02-07T11:06:01Z2022-09-13T23:00:00ZTitle: Nematode communities from a natural oil seep off Svalbard.
Authors: Balsa, J.; Argentino, C.; Riva, F.; Adão, H.; Panieri, G.; Ramalho, S.P.
Abstract: Cold seeps are considered hotspots of energy on the seafloor, establishing unique conditions for
life to thrive. In chemosynthetic-based habitats such as these, sediments from active sites are
typically inhabited by endemic nematode communities which tolerate the local reduced
environmental conditions, but no studies have been carried out on seep sites so far north in the
Arctic. Under the scope of the AKMA project, an oil seep site located offshore Svalbard was
sampled for the first time to investigate the associated meiofauna assemblages with methane
and crude oil seepage. Replicated samples were collected by means of the blade and push cores
handled by the ROV Ægir6000, both on bacterial mats with evident gas and oil seepage, as well
as in sediments nearby without evident seepage activity, as reference. Sediments collected were
used to characterize the community structure and diversity of the meiofauna taxa, particularly
the nematode assemblages, as well as key environmental parameters (i.e, sediment and porewater geochemistry, organic content, grain size). Preliminary observations showed no major
differences in total meiofauna density between microhabitats, with a predominance of
nematodes (>90%), followed by harpacticoid copepods and nauplii larvae, typically seen in other
deep-sea environments. However, an in-depth investigation into the nematode assemblages
revealed that bacterial mats hosted an extremely low diversity of nematode species, by
comparison, to the reference locations. Bacterial mat-associated assemblages were
predominantly composed of a single species, Dichromadora sp.1, followed by Halomonhystera cf.
disjuncta and Linhomoidae sp. 1. Evidence of morphological and reproductive adaptations in the
species present seems to allow them to survive in this toxic environment, namely due to high
concentrations of hydrogen sulfide and oil presence. The findings resulting from this study
contribute to a large gap in the understanding of how infauna thrive in extreme environments
with the presence of hydrocarbons in the Arctic2022-09-13T23:00:00ZSpatial distribution patterns of microbiome and free-living benthic nematodes in response to sediment ecological conditions in Sado estuary, Portugal.Vieira, S.Sroczyńska, K.Adão, H.Vicente, C.http://hdl.handle.net/10174/321162022-05-30T11:01:10Z2022-05-01T23:00:00ZTitle: Spatial distribution patterns of microbiome and free-living benthic nematodes in response to sediment ecological conditions in Sado estuary, Portugal.
Authors: Vieira, S.; Sroczyńska, K.; Adão, H.; Vicente, C.
Abstract: Spatial distribution patterns of microbiome and free-living benthic nematodes in response to sediment ecological conditions in Sado estuary, Portugal.
Soraia Vieira1 (svvieira@uevora.pt), Kasia Sroczyńska1, Marta Martins2, Maria Costa2, Joana Neves2, Helena Adão1, Cláudia Vicente3
1 MARE-UÉ - Marine and Environmental Sciences Centre, University of Évora, University of Évora, Évora, Portugal; 2 MARE – Marine and Environmental Sciences Centre, NOVA School of Science and Technology (FCT NOVA), Lisbon, Portugal; 3 MED – Mediterranean Institute for Agriculture, Environment and Development, University of Évora, Évora, Portugal
Sediment microbiome has an essential role in regulating ecosystem functions, not only regulating primary productivity and nutrient cycling but also shaping trophic interactions with higher trophic levels [1]. While the importance of microbiome in terrestrial soil systems is being widely recognized, its role in marine aquatic environments remains much less studied [2]. Microbiome can be highly affected by bottom up (abiotic factors) and top down (predation by meiofauna) effects [3]. Understanding the interaction effect between abiotic and biotic factors on microbiome communities will be an essential step for future predictions of ecosystem stability. To address this knowledge gap we studied spatial distribution patterns of microbiome communities and nematode assemblages in highly heterogenous Sado Estuary, SW Portugal. The samples were taken from three contrasting sites with varying sediment characteristics and human impact degrees. From each site, three replicate samples for sediment characterization (total organic matter, granulometry, total C and N, chlorophyll a and phaeopigments, contaminants: heavy metals and metalloids, organochlorine pesticides, PAH and PCBs), microbiome (sensu lato) and nematode community were taken. Total DNA from sediment was extracted using DNeasy Power Soil kit® (MOBIO, Qiagen) and processed for Illumina MiSeq platform sequencing targeting the V3 and V4 region of 16S rRNA gene. Sediment characterization indicated heterogeneity between sites with distinct levels of contamination, which resulted in contrasting microbial communities. All sites showed a high α-biodiversity with predominance of Proteobacteria phylum, particularly Woeseiaceae, Desulfobacteraceae and Desulfobulbaceae families. Beside this heterogeneity in microbiome community, β-diversity of microbiome communities was demonstrated to be very high, greatly discriminating among all three sites. Instead, nematode assemblages did not yield clear distributional patterns suggesting that their response is rather driven by the within site specific factors, acting at the smaller spatial scales. Studying the relations between sediment ecological conditions and microbiome and meiobenthic communities greatly advance our understanding on benthic ecosystem functioning.
Keywords: Sediment microbiome - Benthic nematodes - Metagenomics - spatial distribution - Interactions.
References:
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[1] Thakur, M. P., & Geisen, S. (2019). Trophic regulations of the soil microbiome. Trends in Microbiology. 27(9):771-780.
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[2] Avó, A. P., Daniell, T. J., Neilson, R., Oliveira, S., Branco, J., & Adão, H. (2017). DNA barcoding and morphological identification of benthic nematodes assemblages of estuarine intertidal sediments: advances in molecular tools for biodiversity assessment. Frontiers in Marine Science. 4: 66.
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[3] Zhang, Q., Goberna, M., Liu, Y., Cui, M., Yang, H., Sun, Q. et al. (2018). Competition and habitat filtering jointly explain phylogenetic structure of soil bacterial communities across elevational gradients. Environmental Microbiology. 20(7): 2386-2396.2022-05-01T23:00:00ZMulti-element profiles as a fingerprint to discriminate estuarine R. philippinarum populations.Vieira, SoraiaBarrulas, PedroChainho, PaulaDias, CristinaSroczynska, KatarzynaAdão, Helenahttp://hdl.handle.net/10174/311832022-02-23T15:11:08Z2021-09-05T23:00:00ZTitle: Multi-element profiles as a fingerprint to discriminate estuarine R. philippinarum populations.
Authors: Vieira, Soraia; Barrulas, Pedro; Chainho, Paula; Dias, Cristina; Sroczynska, Katarzyna; Adão, Helena
Abstract: Filter-feeder bivalves such as non-indigenous Ruditapes philippinarum absorb and accumulate metals,
resulting in multi-element signatures. The goal of this study was to analyse if multi-element profiles of R.
philippinarum can discriminate between spatial and temporal patterns of estuarine bivalves’
populations.
Spatial and temporal variability patterns of chemical profiles were assessed by collecting samples of R.
philippinarum and sediment at i) three sites with different environmental and physiological conditions of
clams, ii) located within two Portuguese estuaries (Tagus and Sado estuaries) and iii) sampled at three
different occasions (May 2018, January 2019, May 2019). This sampling design hypothesized that there
are significant differences in the bivalves’ chemical profiles between estuaries, among sampling sites
and among sampling occasions. The chemical elements were categorized according to the estuarine
geomorphology sources (Se,Co, Ni and Cu), elements with function in metabolic processes of the clams
(Mn, Fe, Zn and Cr) and elements derived from the anthropogenic inputs (As, Pb and Cd). The multielement concentrations of clams’ soft tissues and sediments were obtained using a powerful analytical
technique, ICP-MS (inductively coupled plasma mass spectrometry). Multivariate differences were
tested in multi-element concentrations of bivalves’ soft tissues and sediments. Results revealed that Zn,
Co, Ni and Pb were the main contributors for the chemical signatures of Tagus estuary populations,
whilst for the Sado estuary populations were Cu, Fe, Cr, As and Cd. These elements were representative
of all elemental categories and proved to be spatial and temporal habitat discriminators of bivalves’
estuarine populations. The multi-element signatures of R. philippinarum as a natural tag derived from
the physical and chemical conditions of its habitat can be considered as a potential rapid tool for
ecological biomonitoring and habitat assessment, accounting for spatial and temporal habitat
differences of estuarine populations.2021-09-05T23:00:00Z