bcodmo_dataset_986875_v1 eng UTF8 dataset service Adam Shepherd BCO-DMO 508-289-2772 266 Woods Hole Rd. MS#36 Woods Hole MA 02543 USA erddap@bco-dmo.org pointOfContact 2026-04-08 ISO 19115-2 Geographic Information - Metadata Part 2 Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) 3 column row temporal [Water Column Methane Oxidation Gulf of Alaska] - Water column methane, methane oxidation, and pmoA gene copies above methane seeps determined from samples collected off the Aleutian Islands, Gulf of Alaska on R/V Atlantis cruise AT50-24 in May to June 2024 (Collaborative Research: Redefining the footprint of deep ocean methane seepage for benthic ecosystems) 2026-04-08 creation erddap.bco-dmo.org bcodmo_dataset_986875_v1 BCO-DMO info@bco-dmo.org https://osprey.bco-dmo.org/dataset/986875 information web browser Background Information Background information from the source information originator Cold seeps along the eastern Aleutian subduction zone in the Gulf of Alaska fuel benthic ecosystems through microbial methane (CH₄) consumption, yet the structure and controls of water column CH₄ oxidation in these deep, cold waters remain poorly resolved. During a May–June 2024 expedition with the R/V Atlantis and HOV Alvin, we studied CH₄ and its bacterial oxidation from surface to seafloor above three deep seep sites (2000 to 5000 meters): Edge, Shumagin, and Sanak, by combining radiotracer incubations with pmoA gene  profiling. CH₄ oxidation occurred throughout the water column, with peak rates (1 to 242 nanomoles per liter per day) in near-seafloor Alvin samples and 0.1 to 0.25 nanomoles per liter per day in CTD rosette samples 10 to 30 meters above bottom. Rates varied by site and depth. CH₄ oxidation in surface waters, coinciding with an algal bloom, suggests cryptic cycling via in situ production and consumption. A ~325-meter near-bottom CTD transect at Sanak revealed lateral gradients in CH₄ and oxidation aligned with bottom currents, with oxidation highest near hydrate-bearing gas vents and at the off-seep distal end. These findings show that aerobic CH₄ oxidation peaks near the seafloor to ~30 meters above but extends laterally and vertically beyond active seepage. Oxidation was detected even where methanotroph gene abundance was low, potentially indicating the influence of lateral CH₄ transport and tidal currents. The methanosphere thus emerges as a dynamic and spatially diffuse microbial system shaped by CH₄ availability and physical transport processes. BCO-DMO info@bco-dmo.org https://osprey.bco-dmo.org/dataset/986875 information web browser Background Information Background information from the source information pointOfContact earth science atmosphere ocean biosphere biology environment theme BCO-DMO project time latitude longitude theme CF The data may be used and redistributed for free but is not intended for legal use, since it may contain inaccuracies. Neither the data Contributor, ERD, NOAA, nor the United States Government, nor any of their employees or contractors, makes any warranty, express or implied, including warranties of merchantability and fitness for a particular purpose, or assumes any legal liability for the accuracy, completeness, or usefulness, of this information. BCO-DMO largerWorkCitation project eng geoscientificInformation 1 -162.5903 -147.9998 53.74744 57.4803 seconds 2024-05-17T05:12:00Z 2024-06-05T21:55:00Z [Water Column Methane Oxidation Gulf of Alaska] - Water column methane, methane oxidation, and pmoA gene copies above methane seeps determined from samples collected off the Aleutian Islands, Gulf of Alaska on R/V Atlantis cruise AT50-24 in May to June 2024 (Collaborative Research: Redefining the footprint of deep ocean methane seepage for benthic ecosystems) 2026-04-08 creation BCO-DMO info@bco-dmo.org https://osprey.bco-dmo.org/dataset/986875 information web browser Background Information Background information from the source information originator Cold seeps along the eastern Aleutian subduction zone in the Gulf of Alaska fuel benthic ecosystems through microbial methane (CH₄) consumption, yet the structure and controls of water column CH₄ oxidation in these deep, cold waters remain poorly resolved. During a May–June 2024 expedition with the R/V Atlantis and HOV Alvin, we studied CH₄ and its bacterial oxidation from surface to seafloor above three deep seep sites (2000 to 5000 meters): Edge, Shumagin, and Sanak, by combining radiotracer incubations with pmoA gene  profiling. CH₄ oxidation occurred throughout the water column, with peak rates (1 to 242 nanomoles per liter per day) in near-seafloor Alvin samples and 0.1 to 0.25 nanomoles per liter per day in CTD rosette samples 10 to 30 meters above bottom. Rates varied by site and depth. CH₄ oxidation in surface waters, coinciding with an algal bloom, suggests cryptic cycling via in situ production and consumption. A ~325-meter near-bottom CTD transect at Sanak revealed lateral gradients in CH₄ and oxidation aligned with bottom currents, with oxidation highest near hydrate-bearing gas vents and at the off-seep distal end. These findings show that aerobic CH₄ oxidation peaks near the seafloor to ~30 meters above but extends laterally and vertically beyond active seepage. Oxidation was detected even where methanotroph gene abundance was low, potentially indicating the influence of lateral CH₄ transport and tidal currents. The methanosphere thus emerges as a dynamic and spatially diffuse microbial system shaped by CH₄ availability and physical transport processes. ERDDAP tabledap 1 -162.5903 -147.9998 53.74744 57.4803 seconds 2024-05-17T05:12:00Z 2024-06-05T21:55:00Z tight ERDDAPtabledapDatasetQueryAndAccess https://erddap.bco-dmo.org/erddap/tabledap/bcodmo_dataset_986875_v1 ERDDAP:tabledap ERDDAP-tabledap ERDDAP's tabledap service (a flavor of OPeNDAP) for tabular (sequence) data. Add different extensions (e.g., .html, .graph, .das, .dds) to the base URL for different purposes. download [Water Column Methane Oxidation Gulf of Alaska] - Water column methane, methane oxidation, and pmoA gene copies above methane seeps determined from samples collected off the Aleutian Islands, Gulf of Alaska on R/V Atlantis cruise AT50-24 in May to June 2024 (Collaborative Research: Redefining the footprint of deep ocean methane seepage for benthic ecosystems) 2026-04-08 creation BCO-DMO info@bco-dmo.org https://osprey.bco-dmo.org/dataset/986875 information web browser Background Information Background information from the source information originator Cold seeps along the eastern Aleutian subduction zone in the Gulf of Alaska fuel benthic ecosystems through microbial methane (CH₄) consumption, yet the structure and controls of water column CH₄ oxidation in these deep, cold waters remain poorly resolved. During a May–June 2024 expedition with the R/V Atlantis and HOV Alvin, we studied CH₄ and its bacterial oxidation from surface to seafloor above three deep seep sites (2000 to 5000 meters): Edge, Shumagin, and Sanak, by combining radiotracer incubations with pmoA gene  profiling. CH₄ oxidation occurred throughout the water column, with peak rates (1 to 242 nanomoles per liter per day) in near-seafloor Alvin samples and 0.1 to 0.25 nanomoles per liter per day in CTD rosette samples 10 to 30 meters above bottom. Rates varied by site and depth. CH₄ oxidation in surface waters, coinciding with an algal bloom, suggests cryptic cycling via in situ production and consumption. A ~325-meter near-bottom CTD transect at Sanak revealed lateral gradients in CH₄ and oxidation aligned with bottom currents, with oxidation highest near hydrate-bearing gas vents and at the off-seep distal end. These findings show that aerobic CH₄ oxidation peaks near the seafloor to ~30 meters above but extends laterally and vertically beyond active seepage. Oxidation was detected even where methanotroph gene abundance was low, potentially indicating the influence of lateral CH₄ transport and tidal currents. The methanosphere thus emerges as a dynamic and spatially diffuse microbial system shaped by CH₄ availability and physical transport processes. OPeNDAP 1 -162.5903 -147.9998 53.74744 57.4803 seconds 2024-05-17T05:12:00Z 2024-06-05T21:55:00Z tight OPeNDAPDatasetQueryAndAccess https://erddap.bco-dmo.org/erddap/tabledap/bcodmo_dataset_986875_v1 OPeNDAP:OPeNDAP OPeNDAP An OPeNDAP service for tabular (sequence) data. Add different extensions (e.g., .html, .das, .dds) to the base URL for different purposes. download physicalMeasurement Date_UTC String Date_utc CTD_Start_Time_or_Alvin_Niskin_Closure_UTC String Ctd_start_time_or_alvin_niskin_closure_utc time double Iso_datetime_utc Site_Name String Site_name CTD_or_Alvin_Sample_Number String Ctd_or_alvin_sample_number Waypoint int Waypoint Water_Depth float Water_depth Methane float Methane Methane_oxidation_Replicate_1 float Methane_oxidation_replicate_1 Methane_oxidation_Replicate_2 float Methane_oxidation_replicate_2 Methane_oxidation_Replicate_3 float Methane_oxidation_replicate_3 pmoA_gene_copy_number float Pmoa_gene_copy_number Adam Shepherd BCO-DMO 508-289-2772 266 Woods Hole Rd. MS#36 Woods Hole MA 02543 USA erddap@bco-dmo.org distributor OPeNDAP DAP/2.0 https://erddap.bco-dmo.org/erddap/tabledap/bcodmo_dataset_986875_v1.html order Data Subset Form ERDDAP's version of the OPeNDAP .html web page for this dataset. Specify a subset of the dataset and download the data via OPeNDAP or in many different file types. download https://erddap.bco-dmo.org/erddap/tabledap/bcodmo_dataset_986875_v1.graph order Make-A-Graph Form ERDDAP's Make-A-Graph .html web page for this dataset. Create an image with a map or graph of a subset of the data. mapDigital This record was created from dataset metadata by ERDDAP Version 2.22