Hudson Canyon Research Articles

Ocean quahog (Arctica islandica) growth rate analyses of four populations from the Mid-Atlantic Bight and Georges Bank

Growth rates from 1480 Arctica islandica from New Jersey, collected in 2019 from north and south of the Hudson Canyon, were analyzed and compared to animals obtained from Long Island and Georges Bank. New Jersey represents the southern portion of the A. islandica stock in the Mid-Atlantic Bight, and animals here may experience warmer temperatures compared to their northern counterparts. Arctica islandica from New Jersey have slower maximum growth rates compared to northern A. islandica, particularly from Georges Bank; however, A. islandica from south of the Hudson Canyon have higher growth rates at older ages compared to the other three sites. Growth rates have been increasing over the past three centuries, potentially due to increasing bottom water temperatures, with time to maturity and time to commercial size drastically decreasing, leading to fewer years for reproduction prior to recruiting into the fishery. Three growth models, von Bertalanffy, Tanaka, and modified Tanaka were examined for goodness of fit to growth data. The von Bertalanffy, commonly used in fisheries management, had the worst fit for all populations, males and females, and at all 20-year cohort groups, and should not be used in the management of this species. The Tanaka and modified Tanaka models are recommended in its place, as these models best fit A. islandica growth at young (Tanaka) and older (>160 years, modified Tanaka) ages.

Examination of spatial heterogeneity in population age frequency and recruitment in the ocean quahog (Arctica islandica Linnaeus 1767)

The ocean quahog, Arctica islandica, is a commercially important species on the northwestern Atlantic continental shelf. This species can live over 200 years with ages varying widely per 5-mm size class (shell length), making study of age-related demographics difficult. To determine how the demography of this species differs across its range, including age frequencies, age-at-length relationships, and sex ratios, ocean quahogs from multiple sites distributed from the Mid-Atlantic Bight to Georges Bank were studied. The age and length frequencies from two populations collected in 2019 from New Jersey, north and south of Hudson Canyon (39.840556 N, 72.821667 W and 39.33 N, 73.545 W, respectively), were analyzed and compared to two other populations from Long Island (40.09658 N, 73.01057 W) and Georges Bank (40.72767 N, 67.79850 W), previously collected in 2015 and 2017. Sex-specific differences were also analyzed to determine how said differences influenced a range of demographic metrics. Though some similarities in recruitment trends exist, likely caused by large-geographic-scale environmental conditions, each site contains a distinct population with distinct demographics. Recruitment is consistent over hundreds of years, but year-to-year and decadal-length variations are apparent. One age–length key may potentially be used to represent Long Island and northern New Jersey, but the remaining sites are significantly dissimilar. Sex ratios also vary, potentially caused by differential survival of one sex during certain times in the past. Mortality rates for Georges Bank are distinctly higher compared to the other populations. Based on these results, the use of separate age–length keys would seem necessary for each population and each sex.

Defining Patterns in Ocean Quahog (Arctica islandica) Sexual Dimorphism along the Mid-Atlantic Bight

The ocean quahog, Arctica islandica (Linnaeus 1767), is a commercially important species along the western Atlantic continental shelf. It is a long-lived species, frequently reaching ages over 200 y. Uniquely, it is one of the few bivalves to display sexual dimorphism, in that females grow to sizes larger than those of males. This phenomenon is believed to occur because males reach sexual maturity before females and, thus, have slower growth rates earlier. The growth rates of A. islandica from four sites across the Mid-Atlantic Bight, Georges Bank, Long Island (LI), and north and south of the Hudson Canyon, were measured to determine patterns in growth between males and females. Females begin to outgrow males between the ages of 5 and 15 y at sizes 50–55 mm, though this varies amongst the sites and between decades. Each of the sites is unique in some way, but three sex-dependent growth dynamics are observed. Most commonly, the two sexes diverge in size with females outpacing males in growth rates after the first 5–15 y of life. This outcome occurs at all sites and is generally the most common outcome across decades. In a few cases, female growth rates outpace the males very early in ontogeny. Such cases occur at two sites north of Hudson Canyon, both on the LI continental shelf. Most rarely, the two sexes maintain similar growth rates. This is observed for a few decades at the most southern site. In the population as a whole, these rare outcomes have limited influence on the population so that female-to-male ratio consistently increases with increasing size. This sexually dimorphic growth is not caused by protandry, nor is it compensation for a differential mortality rate between the sexes. Cases where males grow as fast as females may be just as easily indicative of a constraint on female growth as a facilitation on male growth. Egg sizes in A. islandica are larger than those of most other bivalves with planktotrophic larvae. Accordingly, another viable hypothesis is that differential growth is an adaptation to support the large egg sizes in females, where larger female size is essential to counterweigh the consequent reduced fecundity due to larger egg volume.

Observing Winter Carbonate Chemistry Dynamics Throughout the Mid-Atlantic Bight Shelf Using Novel Glider Technology

Increased atmospheric carbon dioxide (CO2) has led to global climate change and ocean acidification (OA) via the absorption of atmospheric CO2 by the ocean. Coastal shelves are also affected by various processes that influence the acidity of seawater, causing acidity to vary over time and space. These variations in ocean acidity can negatively impact marine species, especially calcifying organisms such as surfclams and sea scallops. In the Mid-Atlantic Bight (MAB), a subsection of the U.S. Northeast Shelf (NES), this variation in acidity generates ecological and economic concerns as the MAB is home to some of the nation’s most productive and profitable estuaries and fisheries. In this study, Rutgers University (southern MAB) and Stony Brook University (northern MAB, Hudson Canyon) deployed two gliders equipped with sensors measur-ing depth, temperature, salinity, pH, dissolved oxygen, and chlorophyll to monitor winter 2021 carbonate chemistry conditions on the shelf as well as in slope waters of the MAB. For both deployments, measured pH and calculated aragonite saturation state (Ωarag) showed opposing patterns, with high pH and low Ωarag in shelf/nearshore and low pH and high Ωarag in slope waters. These trends were attributed to different driving factors whereas pH was more influenced by biological processes (i.e. photo-synthesis) and Ωarag was influenced mostly by thermodynamics and chemical factors (i.e. temperature, total alkalinity). The results of this study underscore the importance of monitoring coastal acidity to understand potential impacts on important species.

Neural net detection of seismic features related to gas hydrates and free gas accumulations on the northern U.S. Atlantic margin

Bottom-simulating reflections (BSRs) that sometimes mark the base of the gas hydrate stability zone in marine sediments are often identified based on the reverse polarity reflections that cut across stratigraphic layering in seismic amplitude data. On the northern U.S. Atlantic margin (USAM) between Cape Hatteras and Hudson Canyon, legacy seismic data have revealed pronounced BSRs south of the deepwater extension of Hudson Canyon and more subtle ones from offshore Delaware south to Cape Hatteras, where the reflections sometimes follow stratigraphic layering. Using high-resolution seismic data acquired during the 2018 Mid-Atlantic Resource Imaging Experiment and a supervised neural net, we identify seismic features associated with gas hydrates and/or the top of gas between Hudson Canyon and Cape Hatteras. Using seismic attributes especially sensitive to the presence of gas, we train a neural network algorithm on seismic data from an area with strong BSRs and then apply the model to the rest of the data set. The results indicate that gas hydrate and/or shallow free gas are significantly more widespread on the northern part of the USAM than previously known. Seismic indicators of gas extend landward from the 2000 m isobath to the upper continental slope in sectors with (offshore Virginia) and, to a lesser extent, without (offshore New Jersey) pervasive upper slope methane seeps. Higher sand content and intermediate sediment thickness, factors related to the container size and gas charge in a petroleum systems framework, are associated with more robust gas indicators.

Seasonal variations in multi-year active acoustic surveys of fish and zooplankton in the New York Bight

Active acoustic surveys provide fine-scale measurements over broad spatial and temporal scales of organism abundance in the water column which can be useful as ecosystem indicators. As part of a long-term time series monitoring program, we conducted seasonal surveys within the New York Bight beginning in 2017. The survey comprises eight transects that extend from near-shore to the continental shelf break, and include multiple stations within each transect where net tows and CTD casts are conducted. Acoustic backscatter measurements at 38, 70, 120, and 200 kHz from the water column were integrated (NASC, m2 nmi−2) to examine the distribution and relative abundance of pelagic scatterers. Generally, NASC was highest during the summer and fall surveys, which corresponds to expected seasonal migrations of fish and squid in this area. Winter NASC distributions were highest in waters deeper than 50 m, but increased nearshore during the summer and fall surveys. Backscatter also appeared to be associated with bathymetric features, such as the shelfbreak and the Hudson Canyon, and in some cases with hydrographic fronts and gradients. These data are the first steps in a longer-term monitoring program of pelagic organisms in the New York Bight.

Source detection and localization in the ocean with a Bayesian approach

Source localization and detection of sound sources in the ocean are investigated from a Bayesian Matched Field Processing perspective. Unknown parameters comprise the source spectrum along with source location; the spectrum is estimated within the localization and detection process. We develop incoherent and coherent processors, integrating the source spectrum estimation employing a Gibbs sampler. Using synthetic data we find that the coherent processor is superior to the incoherent processor and the standard Matched Field approach both in terms of source location estimates and uncertainty. The coherent and incoherent techniques are also applied to real data from the Hudson Canyon experiment with the same conclusion. Employing Receiver Operating Characteristic (ROC) curves, the coherent and incoherent processors are evaluated and compared in the task of joint detection and localization as well. The coherent detector/localization processor is superior to the incoherent one. Joint detection and localization performance is evaluated with Localization-ROC curves. [Work supported by ONR.]

Estimating the Impact of Seep Methane Oxidation on Ocean pH and Dissolved Inorganic Radiocarbon Along the U.S. Mid‐Atlantic Bight

AbstractOngoing ocean warming can release methane (CH4) currently stored in ocean sediments as free gas and gas hydrates. Once dissolved in ocean waters, this CH4 can be oxidized to carbon dioxide (CO2). While it has been hypothesized that the CO2 produced from aerobic CH4 oxidation could enhance ocean acidification, a previous study conducted in Hudson Canyon shows that CH4 oxidation has a small short‐term influence on ocean pH and dissolved inorganic radiocarbon. Here we expand upon that investigation to assess the impact of widespread CH4 seepage on CO2 chemistry and possible accumulation of this carbon injection along 234 km of the U.S. Mid‐Atlantic Bight. Consistent with the estimates from Hudson Canyon, we demonstrate that a small fraction of ancient CH4‐derived carbon is being assimilated into the dissolved inorganic radiocarbon (mean fraction of 0.5 ± 0.4%). The areas with the highest fractions of ancient carbon coincide with elevated CH4 concentration and active gas seepage. This suggests that aerobic CH4 oxidation has a greater influence on the dissolved inorganic pool in areas where CH4 concentrations are locally elevated, instead of displaying a cumulative effect downcurrent from widespread groupings of CH4 seeps. A first‐order approximation of the input rate of ancient‐derived dissolved inorganic carbon (DIC) into the waters overlying the northern U.S. Mid‐Atlantic Bight further suggests that oxidation of ancient CH4‐derived carbon is not negligible on the global scale and could contribute to deepwater acidification over longer time scales.

A coupled mode model for omnidirectional three-dimensional underwater sound propagation.

A fully three-dimensional (3D) omnidirectional numerical coupled mode model of acoustic propagation is detailed. A combination of normal mode and finite element computational methods is applied to produce the numerical results. The technique is tested in a strongly range-dependent ocean environment modeled after the Hudson Canyon. Modeled sound from three source locations selected over different bathymetric depths is examined to determine capabilities and difficulties associated with varying numbers of propagating vertical modes across the horizontal domain, and variable amounts of mode coupling. Model results are compared to those from a unidirectional Cartesian 3D parabolic equation simulation, and from adiabatic (uncoupled) simulations to illustrate the capabilities of the techniques to study the influences of coupling, strong refraction, and reflection.

Spillover of sea scallops from rotational closures in the Mid-Atlantic Bight (United States)

AbstractWe examined evidence for larval spillover (increased recruitment outside the closures) of Atlantic sea scallops (Placopecten magellanicus) due to rotational closures in the Mid-Atlantic Bight using a 40-year fisheries survey time series and a larval transport model. Since the first closure of the Hudson Canyon South (HCS) area in 1998, mean recruitment in the two areas directly down-current from this closure, Elephant Trunk (ET) and Delmarva (DMV), increased significantly by factors of about 7 and 2, respectively. Stock–recruit plots indicate that low biomasses in HCS were associated with reduced mean recruitment in ET and DMV. Simulations indicate that larvae spawned in HCS often settle in the two downstream areas and that model-estimated settlement (based on gonad biomass in HCS and year-specific larval transport between the areas) is correlated with observed recruitment. This study gives strong evidence that the rotational closure of HCS has induced increased recruitment in down-current areas.

Physiological and behavioral sexual maturity of female red deep-sea crabs Chaceon quinquedens (Smith, 1879) (Decapoda: Brachyura: Geryonidae) in the Mid-Atlantic Bight

Abstract We describe the physiological and behavioral maturity of the red deep-sea crab, Chaceon quinquedens (Smith, 1879), using ovary and oocyte development and morphological features to estimate the size at 50% sexual maturity (SM50) for females in the Mid-Atlantic Bight. This economically important species inhabits the continental shelf and slope of the western Atlantic from Nova Scotia, Canada to the Gulf of Mexico. Samples were collected by trawling in 2011–2013 and by traps in 2014–2016. We used histological analysis to describe the stages of ovarian development. Five stages of ovarian development were identified: 1, immature; 2, early maturing; 3, late maturing; 4, mature; and 5, redeveloping. A logistic model was used to estimate the SM50 using maximum likelihood methods. Physiological SM50 varied among geographic locations and was estimated at 61.2 mm CL and 70.8 mm CL for females collected near Hudson Canyon and Baltimore and Norfolk canyons, respectively. Behavioral SM50 decreased with latitude and was estimated at 53.9 mm CL, 62.5 mm CL and 65.5 mm CL for Hudson, Baltimore, and Norfolk canyons, respectively. Results implied asynchrony between physiological and behavioral sexual maturity, suggesting that mating occurs prior to completion of ovarian development. This study provides the first evidence of a latitudinal trend in sexual maturity for C. quinquedens. Further investigation is needed to understand the cause of the latitudinal trend as our study presented limitations. Results provide useful information for fisheries management about the reproductive biology of C. quinquedens.

Investigations of Aerobic Methane Oxidation in Two Marine Seep Environments: Part 1—Chemical Kinetics

AbstractMicrobial aerobic oxidation is known to be a significant sink of marine methane (CH4), contributing to the relatively minor atmospheric release of this greenhouse gas over vast stretches of the ocean. However, the chemical kinetics of aerobic CH4 oxidation are not well established, making it difficult to predict and assess the extent that CH4 is oxidized in seawater following seafloor release. Here we investigate the kinetics of aerobic CH4 oxidation using mesocosm incubations of fresh seawater samples collected from seep fields in Hudson Canyon, U.S. Atlantic Margin and MC118, Gulf of Mexico to gain a fundamental chemical understanding of this CH4 sink. The goals of this investigation were to determine the response or lag time following CH4 release until more rapid oxidation begins, the reaction order, and the stoichiometry of reactants utilized (i.e., CH4, oxygen, nitrate, phosphate, trace metals) during CH4 oxidation. The results for both Hudson Canyon and MC118 environments show that CH4 oxidation rates sharply increased within less than one month following the CH4 inoculation of seawater. However, the exact temporal characteristics of this more rapid CH4 oxidation varied based on location, possibly dependent on the local circulation and biogeochemical conditions at the point of seawater collection. The data further suggest that methane oxidation behaves as a first‐order kinetic process and that the reaction rate constant remains constant once rapid CH4 oxidation begins.

Bayesian coherent and incoherent matched-field localization and detection in the ocean.

Matched-field processing is applied to source localization and detection of sound sources in the ocean. The source spectrum is included in the set of unknown parameters and is estimated in the localization/detection process. Bayesian broadband (multi-tonal) incoherent and coherent processors are developed, integrating the source spectrum estimation using a Gibbs sampler and are first evaluated in source localization via point estimates and probability density functions obtained from synthetic signals. The coherent performance is superior to the incoherent one both in terms of source location estimates and density spread. The two processors are also applied to real data from the Hudson Canyon experiment. Subsequently, using Receiver Operating Characteristic (ROC) curves, the two processors are evaluated and compared in the task of joint detection and localization. The coherent detector/localization processor is superior to the incoherent one, especially as the number of frequencies increases. Joint detection and localization performance is evaluated with Localization-ROC curves.

Investigations of Aerobic Methane Oxidation in Two Marine Seep Environments: Part 2—Isotopic Kinetics

AbstractDuring aerobic oxidation of methane (CH4) in seawater, a process which mitigates atmospheric emissions, the 12C‐isotopologue reacts with a slightly greater rate constant than the 13C‐isotopologue, leaving the residual CH4 isotopically fractionated. Prior studies have attempted to exploit this systematic isotopic fractionation from methane oxidation to quantify the extent that a CH4 pool has been oxidized in seawater. However, cultivation‐based studies have suggested that isotopic fractionation fundamentally changes as a microbial population blooms in response to an influx of reactive substrates. Using a systematic mesocosm incubation study with recently collected seawater, here we investigate the fundamental isotopic kinetics of aerobic CH4 oxidation during a microbial bloom. As detailed in a companion paper, seawater samples were collected from seep fields in Hudson Canyon, U.S. Atlantic Margin, and atop Woolsey Mound (also known as Sleeping Dragon) which is part of lease block MC118 in the northern Gulf of Mexico, and used in these investigations. The results from both Hudson Canyon and MC118 show that in these natural environments isotopic fraction for CH4 oxidation follows a first‐order kinetic process. The results also show that the isotopic fractionation factor remains constant during this methanotrophic bloom once rapid CH4 oxidation begins and that the magnitude of the fractionation factor appears correlated with the first‐order reaction rate constant. These findings greatly simplify the use of natural stable isotope changes in CH4 to assess the extent that CH4 is oxidized in seawater following seafloor release.

Measurements and modeling of acoustic propagation in a scale model canyon.

Two scale-model acoustic propagation experiments were conducted in a laboratory tank to investigate three-dimensional (3D) propagation effects induced by range-dependent bathymetry. The model bathymetry, patterned after measured bathymetric data, represents a portion of the Hudson Canyon at 1:7500 scale. The bottom condition in the scale model is nearly pressure release, and as a result, the bottom reflection and backscattering are stronger than that of the real ocean environment. Measurements are presented for propagation paths oriented along and across the axis of the canyon. The measured data are interpreted using both 3D adiabatic-mode and 3D ray models. For propagation along the canyon axis, horizontal focusing is observed, and the out-of-plane arrivals are identified using the vertical mode/horizontal ray analogy to determine which wall or walls of the canyon refracted the sound. For the across-canyon propagation, out-of-plane arrivals are observed for both forward scattered and backward scattered sound. Using the 3D ray model, an investigation of the horizontal and vertical launch angles is used to identify features on the canyon walls responsible for the measured out-of-plane propagation. For both the along- and across-canyon experiments, the 3D ray model produced a solution that was more accurate and less computationally intensive.

Limited Acute Influence of Aerobic Methane Oxidation on Ocean Carbon Dioxide and pH in Hudson Canyon, Northern U.S. Atlantic Margin

AbstractThe ocean continental shelves host the largest global reservoir of methane (CH4). Despite the great extent of these CH4 reservoirs, much of the CH4 released into deep ocean environments appear to dissolve in seawater prior to atmospheric emission. Once dissolved in ocean water, the CH4 emitted can be aerobically oxidized and converted into either carbon dioxide (CO2) or biomass. While hypotheses have been levied suggesting that the CO2 produced from aerobic methane oxidation could enhance ocean acidification, no empirical research has been performed to confirm or refute this hypothesis. The work presented here investigates local changes in seawater‐dissolved CO2 and pH in a region that is experiencing active CH4 seepage near the upper stability boundary of methane clathrate hydrates. We show that in an area of elevated CH4 concentrations and aerobic oxidation rates, Hudson Canyon, aerobic CH4 oxidation is only responsible for 0.3 ± 0.2% of the observed change in dissolved inorganic carbon. Measurements further show that the remineralization of both old marine and young terrestrial organic carbon is contributing more substantially to the observed changes. While this investigation did not investigate chronic, multiyear changes in ocean acidification due to CH4 oxidation, these results suggest that over short timescales, CH4 oxidation in seep fields does not have an acute influence on seawater pH.

Improved Visualization of Hydroacoustic Plumes Using the Split-Beam Aperture Coherence.

Natural seepage of methane into the oceans is considerable, and plays a role in the global carbon cycle. Estimating the amount of this greenhouse gas entering the water column is important in order to understand their environmental impact. In addition, leakage from man-made structures such as gas pipelines may have environmental and economical consequences and should be promptly detected. Split beam echo sounders (SBES) detect hydroacoustic plumes due to the significant contrast in acoustic impedance between water and free gas. SBES are also powerful tools for plume characterization, with the ability to provide absolute acoustic measurements, estimate bubble trajectories, and capture the frequency dependent response of bubbles. However, under challenging conditions such as deep water and considerable background noise, it can be difficult to detect the presence of gas seepage from the acoustic imagery alone. The spatial coherence of the wavefield measured across the split beam sectors, quantified by the coherence factor (CF), is a computationally simple, easily available quantity which complements the acoustic imagery and may ease the ability to automatically or visually detect bubbles in the water column. We demonstrate the benefits of CF processing using SBES data from the Hudson Canyon, acquired using the Simrad EK80 SBES. We observe that hydroacoustic plumes appear more clearly defined and are easier to detect in the CF imagery than in the acoustic backscatter images.

Megabenthic assemblages at the Hudson Canyon head (NW Atlantic margin): Habitat-faunal relationships

The distribution of megabenthic communities at the head of Hudson Canyon and adjacent continental shelf was studied by means of underwater video transects and still photo imagery collected using a towed camera system. The goal was to explore the relationships between faunal distribution and physical seafloor conditions and to test the hypothesis that increased seafloor heterogeneity in the Hudson Canyon supports a larger diversity of benthic communities, compared with the adjacent continental shelf. Hierarchical cluster analysis was performed to identify benthic assemblages as defined in imagery. The BIO-ENV procedure and the Canonical Correspondence Analysis were carried out to elucidate species groupings in relation to terrain variables extracted from bathymetric data. Species accumulation curves were generated to evaluate species turn over in and out of Hudson Canyon. The results indicate that seafloor morphology is the main physical factor related to benthic community composition and distribution. Assemblages dominated by sponges, zoanthids and cup corals colonized the canyon margins and flanks, and were associated with coarse-grained sediments, while sea pen assemblages were observed along muddy seafloor within the thalweg. An assemblage dominated by sea stars occurred on the shelf, associated with a sandy seafloor. Some assemblages were exclusively observed in the canyon area, suggesting that the increased variability of seafloor composition, together with the oceanographic processes specific to the canyon area, enhance beta diversity. The colonization by benthic suspension feeders within the canyon, in contrast to shelf assemblages, mainly composed of carnivores and detritus feeders could be favored the intense hydrodynamics at the canyon head that increase the availability of suspended organic matter.From the perspective of management and conservation of marine resources, the results obtained support the relevance of Hudson Canyon asa biodiversity hotspot. Such results are of particular significance in light of the recent action promoted by the Mid-Atlantic Fisheries Management Council, that restricts bottom trawling in most of the submarine canyons of the US Atlantic margin, including the Hudson Canyon, to protect cold-water corals from damage by fishing gear.

Measurements and modeling of three-dimensional acoustic propagation in a scale-model canyon

Scale-model acoustic propagation experiments were conducted in a laboratory tank to investigate three-dimensional (3D) propagation effects induced by range-dependent bathymetry. The model bathymetry, patterned after measured bathymetric data, represents a portion of the Hudson Canyon at 1:7500 scale and was fabricated from closed-cell polyurethane foam using a computer-numerically controlled (CNC) milling machine. In the measurement apparatus, a computer-controlled positioning system precisely locates the receiving hydrophone which permits the creation of synthetic horizontal line arrays. Results are shown for propagation paths along and across the axis of the canyon. The measurements are explained using both a hybrid method known as vertical modes/horizontal parabolic equation and a 3D ray model known as Bellhop3D. For propagation along the canyon axis, horizontal focusing is observed and discussed in the context of normal modes. For the across canyon propagation, the reflective foam walls of the canyon ...

Rapid rates of aerobic methane oxidation at the feather edge of gas hydrate stability in the waters of Hudson Canyon, US Atlantic Margin

Aerobic oxidation is an important methane sink in seawater overlying gas seeps. Recent surveys have identified active methane seeps in the waters of Hudson Canyon, US Atlantic Margin near the updip limit of methane clathrate hydrate stability. The close proximity of these seeps to the upper stability limit of methane hydrates suggests that changing bottom water temperatures may influence the release rate of methane into the overlying water column. In order to assess the significance of aerobic methane oxidation in limiting the atmospheric expression of methane released from Hudson Canyon, the total extent of methane oxidized along with integrated oxidation rates were quantified. These calculations were performed by combining the measurements of the natural levels of methane concentrations, stable carbon isotopes, and water current velocities into kinetic isotope models yielding rates ranging from 22.8±17 to 116±76nM/day with an average of 62.7±37nM/day. Furthermore, an average of 63% of methane released into the water column from an average depth of 515m was oxidized before leaving this relatively small study area (6.5km2). Results from the kinetic isotope model were compared to previously-published but concurrently-sampled ex situ measurements of oxidation potential performed using 13C-labeled methane. Ex situ rates were substantially lower, ranging from 0.1 to 22.5nM/day with an average of 5.6±2.3nM/day, the discrepancy likely due to the inherent differences between these two techniques. Collectively, the results reveal exceptionally-rapid methane oxidation, with turnover times for methane as low as 0.3–3.7days, indicating that methane released to the water column is removed quantitatively within the greater extent of Hudson Canyon.