Project description:Untargeted proteomics from a 5,000 km+ transect across the central Pacific Ocean from Hawaii to Tahiti. The expedition crossed multiple biogeochemical provinces, inlcuding the oligotrophic North Pacific Subtropical Gyre, the extremety of the Eastern Tropical North Pacific Oxygen Deficient Zone, and the relatively productive equatorial region associated with upwelling. This dataset focuses on the microbial fraction (0.2-3.0 micrometer filter size) and the microbial community dynamics across these biogeochemical provinces, from the surface oceance to the mesopelagic (1,250 m depth maximum).
Project description:An Autonomous Underwater Vehicle (AUV) and large volume underwater pumps were used to collect microbial biomass from offshore waters of the Sargasso Sea, from surface waters and into the deep ocean. Seawater collection was performed along a transect in the western North Atlantic Ocean beginning near Bermuda and ending off the coast of Massachusetts, capturing metabolic signatures from oligotrophic, continental margin, and productive coastal ecosystems.
Project description:Marine microbial communities are critical for biogeochemical cycles and the productivity of ocean ecosystems. Primary productivity, at the base of marine food webs, is constrained by nutrient availability in the surface ocean, and nutrient advection from deeper waters can fuel photosynthesis. In this study, we compared the transcriptional responses by surface microbial communities after experimental deep water mixing to the transcriptional patterns of in situ microbial communities collected with high-resolution automated sampling during a bloom in the North Pacific Subtropical Gyre. Transcriptional responses were assayed with the MicroTOOLs (Microbiological Targets for Ocean Observing Laboratories) marine environmental microarray, which targets all three domains of life and viruses. The experiments showed that mixing of deep and surface waters substantially affects the transcription of photosystem and nutrient response genes among photosynthetic taxa within 24 hours, and that there are specific responses associated with the addition of deep water containing particles (organisms and detritus) compared to filtered deep water. In situ gene transcription was most similar to that in surface water experiments with deep water additions, showing that in situ populations were affected by mixing of nutrients at the six sampling sites. Together, these results show the value of targeted metatranscriptomes for assessing the physiological status of complex microbial communities.
Project description:In summer 2014, we conducted experiments to determine the effects of different N substrates on phytoplankton communities in the North Pacific Ocean and in the transition zone of the California Current and gyre (Shilova, Mills et al., 2017). Samples were incubated with nitrate, ammonium, urea, and filtered deep water (FDW) for 48 hours (T48). Two treatments added iron, alone (Fe) or with a mix of N substrates (N+Fe), to determine the effects of Fe on the utilization of N substrates. All treatments resulted in changes in phytoplankton cell abundances and photosynthetic activity at both locations, with differences between phytoplankton groups. Prochlorococcus had large increases in biomass in response to ammonium and urea, while both eukaryotic phytoplankton and Synechococcus had only modest biomass increases in response to N+Fe and FDW. Moreover, distinct physiological responses were observed within sub-populations of Prochlorococcus and Synechococcus. In order to understand the variable responses to N substrates among phytoplankton groups and sub-populations in the California Current transition zone, the present work examines transcriptional changes that occurred 24 h after the substrates were added. Specifically, we hypothesize that transcription changes at 24 h indicate which phytoplankton taxa are N-limited, and thus help explain changes in cell abundances and photosynthetic activity by individual phytoplankton groups observed at 48 h. Furthermore, we hypothesize that the diversity in physiological responses within Prochlorococcus and Synechococcus are evident in the transcriptional responses measured at sub-population resolution.
Project description:Dataset from a shipboard incubation experiment of an ocean surface-water microbial community sampled at 25m depth at Station ALOHA in the North Pacific Subtropical Gyre. Incubations were amended with ammonium, glutamate, leucine, nitrate and urea, in two isotopic variants: 15N (to track incorporation by various community members) and 14N (for quantitation of abundance changes by diDO-IPTL).
Project description:In this study we explored the metabolism of unicellular eukaryotic organisms (protists) across a 4,600 km meridional transect in the central Pacific Ocean. The region contains a natural biogeochemical gradient spanning from low nitrogen, oligotrophic waters to a productive equatorial upwelling system. We used a combined geochemical and 'omic approach to characterize the metabolic strategies these organisms rely upon to adapt to changes in their chemical environment. Samples were collected using underwater pumps, capable of filtering hundreds of liters of seawater, from seven stations and 3-13 different depths spanning 20-1,900 m in the water column.
Project description:Function Metabolomics (Native Spray + Metal Addition) of selecteted surface seawater samples (PPL extracts) from Cycle 1 and 2 from the California Current Ecosystems collected during 1706 LTER cruise.
Project description:<p>Coral reef ecosystems are incredibly diverse marine biomes that rely on nutrient cycling by microorganisms to sustain high productivity in generally oligotrophic regions of the ocean. Understanding the composition of extracellular reef metabolites in seawater, the small organic molecules that serve as the currency for microorganisms, may provide insight into benthic-pelagic coupling as well as the complexity of nutrient cycling in coral reef ecosystems. Jardines de la Reina, Cuba is an ideal environment to examine extracellular metabolites across protected and high-quality reefs. Here, we used metabolic methods to quantify specific known metabolites of interest (targeted approach) and to survey trends in metabolite feature composition (untargeted approach) from surface and reef depth (6 – 14 m) seawater overlying forereefs in Jardines de la Reina. We found that untargeted metabolite feature composition was fairly similar between reef depth and surface seawater across the archipelago, corresponding with other biogeochemical and physicochemical measurements and suggesting that environmental conditions were largely homogenous across forereefs within Jardines de la Reina. Additionally, we quantified 32 of 53 detected metabolites, including amino acids, nucleosides, vitamins, and other metabolic intermediates. Two of the quantified metabolites, riboflavin and 5ʹ-methylthioadenosine (MTA), displayed interesting trends by depth and geographic location, respectively. Riboflavin concentrations were higher in reef depth compared to surface seawater, suggesting that riboflavin may be produced by reef organisms at depth and degraded in the surface through photochemical oxidation. 5ʹ-MTA concentrations increased significantly within the central region of the archipelago, displaying biogeographic patterns that warrant further investigation. Here we lay the groundwork for future investigations of variations in metabolite composition across reefs, sources and sinks of reef metabolites, and changes in metabolites over environmental, temporal, and reef health gradients.</p>
Project description:This SuperSeries is composed of the following subset Series: GSE22171: Pacific salmon gill samples: fate tracking in river, sampled in ocean GSE22177: Pacific salmon gill samples: fate tracking in river GSE22347: Pacific salmon gill samples: fate tracking at spawning grounds Refer to individual Series