DSpace Collection:http://hdl.handle.net/10174/1482024-03-28T09:38:24Z2024-03-28T09:38:24ZNematode communities from a natural oil seep off SvalbardBalsa, J.Argentino, C.Riva, F.Adão, H.Panieri, G.Ramalho, S.P.http://hdl.handle.net/10174/339342023-02-07T11:50:49Z2022-12-05T00:00:00ZTitle: 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-seep sediments, where active fluid seepage rich is observed, have been associated with the
presence of endemic nematode communities. Under the scope of the AKMA project, a seep site
located offshore Svalbard was sampled for the first time to investigate the Nematoda assemblages
associated with methane and crude oil seepage. Replicated samples were collected by means of the
blade- and push-cores, on a bacterial mat where active gas and oil seepage was observed, 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 pore-water 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, as typically seen in other deep-sea environments. However, an in-depth
investigation into the nematode assemblages, revealed a low nematode diversity in the bacterial mats
sediments, by comparison, to the reference. Bacterial mat-associated assemblages were
predominantly composed of Halomonhystera sp.1 (39%), followed by a single Chromadoridae species
(32%). Evidence of morphological and reproductive adaptations were observed in several of the
species present and could be indicative of how these organisms are able to survive the toxic
environmental conditions at this seep site, namely high concentrations of hydrogen sulphide and
crude oil. These observations contribute to a large gap in the understanding of how infauna thrive in
extreme environments in the Arctic.2022-12-05T00:00:00ZNematode communities from a natural oil seep off SvalbardBalsa, J.Argentino, C.Riva, F.Adão, H.Panieri, G.Ramalho, S.P.http://hdl.handle.net/10174/339342023-02-07T11:50:49Z2022-12-05T00:00:00ZTitle: 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-seep sediments, where active fluid seepage rich is observed, have been associated with the
presence of endemic nematode communities. Under the scope of the AKMA project, a seep site
located offshore Svalbard was sampled for the first time to investigate the Nematoda assemblages
associated with methane and crude oil seepage. Replicated samples were collected by means of the
blade- and push-cores, on a bacterial mat where active gas and oil seepage was observed, 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 pore-water 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, as typically seen in other deep-sea environments. However, an in-depth
investigation into the nematode assemblages, revealed a low nematode diversity in the bacterial mats
sediments, by comparison, to the reference. Bacterial mat-associated assemblages were
predominantly composed of Halomonhystera sp.1 (39%), followed by a single Chromadoridae species
(32%). Evidence of morphological and reproductive adaptations were observed in several of the
species present and could be indicative of how these organisms are able to survive the toxic
environmental conditions at this seep site, namely high concentrations of hydrogen sulphide and
crude oil. These observations contribute to a large gap in the understanding of how infauna thrive in
extreme environments in the Arctic.2022-12-05T00:00:00ZSpatial distribution patterns of microbiome and free-living benthic nematodes in response to sediment ecological conditions in Sado estuary, Portugal (SW)Soraia, V.Sroczynska, K.Martins, M.Costa, M.H.Neves, J.Adão, HVicente, C.http://hdl.handle.net/10174/339152023-02-07T11:09:58Z2022-04-30T23:00:00ZTitle: Spatial distribution patterns of microbiome and free-living benthic nematodes in response to sediment ecological conditions in Sado estuary, Portugal (SW)
Authors: Soraia, V.; Sroczynska, K.; Martins, M.; Costa, M.H.; Neves, J.; Adão, H; Vicente, C.
Abstract: 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 highly 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.2022-04-30T23:00:00ZSpatial distribution patterns of microbiome and free-living benthic nematodes in response to sediment ecological conditions in Sado estuary, Portugal (SW)Soraia, V.Sroczynska, K.Martins, M.Costa, M.H.Neves, J.Adão, HVicente, C.http://hdl.handle.net/10174/339152023-02-07T11:09:58Z2022-04-30T23:00:00ZTitle: Spatial distribution patterns of microbiome and free-living benthic nematodes in response to sediment ecological conditions in Sado estuary, Portugal (SW)
Authors: Soraia, V.; Sroczynska, K.; Martins, M.; Costa, M.H.; Neves, J.; Adão, H; Vicente, C.
Abstract: 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 highly 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.2022-04-30T23:00:00Z