Woods Hole Open Access Server
Not a member yet
23823 research outputs found
Sort by
Coral fragment surface area calculations utilizing two methods (tin foil and Image J) and corresponding zooxanthellae count data
No full textDataset: Coral Surface Area and Zooxanthellae CountsThis dataset presents coral fragment surface area calculations utilizing two methods (tin foil and Image J) and corresponding zooxanthellae count data. Three coral species were utilized in this experiment: the octocoral, Eunicea flexuosa, and two hard coral species, Acropora cervicornis and Orbicella faveolata.
For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/880711NSF Division of Ocean Sciences (NSF OCE) OCE-1924540, NSF Division of Ocean Sciences (NSF OCE) OCE-192396
Closing the global marine Ra-226 budget reveals the biological pump as a dominant removal flux in the upper ocean
No full textAuthor Posting. © American Geophysical Union, 2022. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 49(12), (2022): e2022GL098087, https://doi.org/10.1029/2022GL098087.Radium isotopes are powerful proxies in oceanography and hydrology. Radium mass balance models, including assessments of submarine groundwater discharge (SGD), often overlook particle scavenging (PS) as a pathway for dissolved radium removal from the world ocean. Here, we build a global ocean 226Ra mass balance model and reevaluate the potential importance of PS. We find that PS is the major 226Ra sink for the upper ocean, removing about 96% of the total input from various sources. Aside from vertical exchange with the lower ocean, SGD is the largest 226Ra source into the upper ocean. The biological pump transfers particles to the deep ocean, resulting in a major but often overlooked impact on the global 226Ra marine budget. Our findings suggest that radium mass balance models should consider PS in systems with high siliceous algae production and export fluxes and long water residence times to prevent underestimation of large-scale SGD fluxes.The authors are grateful to the many researchers and funding agencies responsible for the collection of data and quality control. The authors are very grateful to Jesus Gomez-Velez of Vanderbilt University for suggesting the statistical approach for distribution expansion and helping with the coding. The authors from Ocean University of China were funded by the Natural Science Foundation of China 41876075, 42130410, and 91958214, and Fundamental Research Funds for the Central Universities China 201962003 and 202072001. Funding for M.A.C. was provided by U.S. National Science Foundation OCE-1736277 and a WHOI-OUC Cooperative Research Initiative award. Valentí Rodellas acknowledges financial support from the Beatriu de Pinós postdoctoral programme of the Catalan Government (2019-BP-00241).2022-12-1
Marine Heatwaves and their depth structures on the Northeast U.S. continental shelf
Full text link© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Großelindemann, H., Ryan, S., Ummenhofer, C., Martin, T., & Biastoch, A. Marine Heatwaves and their depth structures on the Northeast U.S. continental shelf. Frontiers in Climate, 4, (2022): 857937, https://doi.org/10.3389/fclim.2022.857937.Marine Heatwaves (MHWs) are ocean extreme events, characterized by anomalously high temperatures, which can have significant ecological impacts. The Northeast U.S. continental shelf is of great economical importance as it is home to a highly productive ecosystem. Local warming rates exceed the global average and the region experienced multiple MHWs in the last decade with severe consequences for regional fisheries. Due to the lack of subsurface observations, the depth-extent of MHWs is not well-known, which hampers the assessment of impacts on pelagic and benthic ecosystems. This study utilizes a global ocean circulation model with a high-resolution (1/20°) nest in the Atlantic to investigate the depth structure of MHWs and associated drivers on the Northeast U.S. continental shelf. It is shown that MHWs exhibit varying spatial extents, with some only occurring at depth. The highest intensities are found around 100 m depth with temperatures exceeding the climatological mean by up to 7°C, while surface intensities are typically smaller (around 3°C). Distinct vertical structures are associated with different spatial MHW patterns and drivers. Investigation of the co-variability of temperature and salinity reveals that over 80% of MHWs at depth (>50 m) coincide with extreme salinity anomalies. Two case studies provide insight into opposing MHW patterns at the surface and at depth, being forced by anomalous air-sea heat fluxes and Gulf Stream warm core ring interaction, respectively. The results highlight the importance of local ocean dynamics and the need to realistically represent them in climate models.This work was supported by a DAAD RISE Worldwide fellowship (to HG), a Feodor-Lynen Fellowship by the Alexander von Humboldt Foundation and the WHOI Postdoctoral Scholar program (to SR), and the James E. and Barbara V. Moltz Fellowship for Climate-Related Research (to CU). Franziska Schwarzkopf performed the integration of the OGCM simulations, which was performed on the Earth System Modeling Project (ESM) partition of the supercomputer JUWELS at the Jülich Supercomputing Centre (JSC)
Interspecific differences in the flow regimes and drag of North Pacific skate egg cases
No full textAuthor Posting. © The Author(s), 2022. This is the author's version of the work. It is posted here by permission of Oxford University Press for personal use, not for redistribution. The definitive version was published in Integrative & Comparative Biology 62(3), (2022): 805-816, https://doi.org/10.1093/icb/icac108.Skates are a diverse group of dorso-ventrally compressed cartilaginous fish found primarily in high-latitude seas. These slow-growing oviparous fish deposit their fertilized eggs into cases, which then rest on the seafloor. Developing skates remain in their cases for 1–4 years after they are deposited, meaning the abiotic characteristics of the deposition sites, such as current and substrate type, must interact with the capsule in a way to promote long residency. Egg cases are morphologically variable and can be identified to species. Both the gross morphology and the microstructures of the egg case interact with substrate to determine how well a case stays in place on a current-swept seafloor. Our study investigated the egg case hydrodynamics of eight North Pacific skate species to understand how their morphology affects their ability to stay in place. We used a flume to measure maximum current velocity, or “break-away velocity,” each egg case could withstand before being swept off the substrate and a tilt table to measure the coefficient of static friction between each case and the substrate. We also used the programing software R to calculate theoretical drag on the egg cases of each species. For all flume trials, we found the morphology of egg cases and their orientation to flow to be significantly correlated with break-away velocity. In certain species, the morphology of the egg case was correlated with flow rate required to dislodge a case from the substrate in addition to the drag experienced in both the theoretical and flume experiments. These results effectively measure how well the egg cases of different species remain stationary in a similar habitat. Parsing out attachment biases and discrepancies in flow regimes of egg cases allows us to identify where we are likely to find other elusive species nursery sites. These results will aid predictive models for locating new nursery habitats and protective policies for avoiding the destruction of these nursery sites.This work was supported by the NSF-REU and FHL Blinks-Beacon for funding JNE. And the Stephen and Ruth Wainwright Endowed Fellowship, BEACON and Hoag Awards, Robert T. Paine Experimental and Field Ecology Award, FHL Award, FHL Marine Science Fund, FHL Student Fund (Kohn), Patricia L. Dudley Endowment for funding KCH.2023-07-0
Metadata for studies from meta-analysis investigating covariance between genetic and environmental (CovGE) effects in phenotypic results
No full textDataset: Metadata from meta-analysis on CovGE in phenotypic resultsCovariance can exist between the genetic and environmental influences on phenotype (CovGE)
and can have an important role in ecological and evolutionary processes in nature and population responses to environmental change. CovGE is commonly called countergradient variation (CnGV; negative CovGE)or cogradient variation (CoGV; positive CovGE)and has been recognized in classic studies that have established several long-standing hypotheses about CnGV and CoGV. For instance, it is hypothesized that CnGV is more prevalent in nature than CoGV, that CnGV is more prevalent in fish, amphibian, and invertebrate taxa, across latitudinal or altitudinal environmental gradients, and more frequently occurs in metabolic compensation traits, including development, growth, feeding, metabolism, and activity, while CoGV is more commonly observed in morphological traits. The recent development of a standardized method to measure CovGE allows for the first rigorous quantitative exploration of these hypotheses. We use meta-analysis and apply the novel quantitative method to test whether the above hypotheses are supported in the literature. We found no differences in frequency of CnGV and CoGV, and no systematic patterns relative to taxa, environmental gradient, or trait type. However, our analyses suggest that CovGE may be as common as gene by environment (GxE) interactions. Given that CovGE is likely to have a strong impact on future outcomes for organisms experiencing environmental change, that significant CovGE occurred frequently, and the lack of systematic patterns in the occurrence of CovGE, we encourage a more widespread application of measuring CovGE.
For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/877414NSF Division of Ocean Sciences (NSF OCE) OCE-176431
Nutrient monitoring data collected as part of macroalgal surveys in Sitka Sound, Alaska kelp beds from 2016 to 2020
No full textDataset: Nutrient monitoringNutrient monitoring data collected as part of macroalgal surveys in Sitka Sound, Alaska kelp beds from 2016 to 2020.
For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/882057NSF Division of Ocean Sciences (NSF OCE) OCE-175260
Seagrass surveys of blade height around artificial reefs in shallow coastal waters off of Abaco, The Bahamas
No full textDataset: Seagrass surveys of blade heightThese data are from seagrass surveys of blade height around artificial reefs in shallow (less than 4 meters) coastal waters in The Bight of Old Robinson, off of Abaco Island, The Bahamas from May to December 2021.
For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/873092NSF Division of Ocean Sciences (NSF OCE) OCE-194862
Query-driven adaptive sampling
Full text linkSubmitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2022.Automated information gathering allows exploration of environments where data is limited and gathering observations introduces risk, such as underwater and planetary exploration. Typically, exploration has been performed in service of a query, with a unique algorithm developed for each mission. Yet this approach does not allow scientists to respond to novel questions as they are raised. In this thesis, we develop a single approach for a broad range of adaptive sampling missions with risk and limited prior knowledge. To achieve this, we present contributions in planning adaptive missions in service of queries, and modeling multi-attribute environments.
First, we define a query language suitable for specifying diverse goals in adaptive sampling. The language fully encompasses objectives from previous adaptive sampling approaches, and significantly extends the possible range of objectives. We prove
that queries expressible in this language are not biased in a way that avoids information. We then describe a Monte Carlo tree search approach to plan for all queries in our language, using sample based objective estimators embedded within tree search.
This approach outperforms methods that maximize information about all variables in hydrocarbon seep search and fire escape scenarios. Next, we show how to plan when the policy must bound risk as a function of reward. By solving approximating problems, we guarantee risk bounds on policies with large numbers of actions and continuous observations, ensuring that risks are only taken when justified by reward.
Exploration is limited by the quality of the environment model, so we introduce Gaussian process models with directed acyclic structure to improve model accuracy under limited data. The addition of interpretable structure allows qualitative expert
knowledge of the environment to be encoded through structure and parameter constraints. Since expert knowledge may be incomplete, we introduce efficient structure learning over structural models using A* search with bounding conflicts. By placing
bounds on likelihood of substructures, we limit the number of structures that are trained, significantly accelerating search. Experiments modeling geographic data show that our model produces more accurate predictions than existing Gaussian process
methods, and using bounds allows structure to be learned in 50% of the time.The work in this thesis was supported by the Exxon Mobil Corporation as part of the MIT Energy Initiative under the project ‘Autonomous System for Deep Sea Hydrocarbon Detection and Monitoring’, NASA’s PSTAR program under the project
‘Cooperative Exploration with Under-actuated Autonomous Vehicles in Hazardous Environments’, and the Vulcan Machine Learning Center for Impact under the project ‘Machine Learning Based Persistent Autonomous Underwater Scientific Studies’
Air-Sea trace gas fluxes: direct and indirect measurements
Full text link© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Fairall, C. W. W., Yang, M., Brumer, S. E. E., Blomquist, B. W. W., Edson, J. B. B., Zappa, C. J. J., Bariteau, L., Pezoa, S., Bell, T. G. G., & Saltzman, E. S. S. Air-Sea trace gas fluxes: direct and indirect measurements. Frontiers in Marine Science, 9, (2022): 826606, https://doi.org/10.3389/fmars.2022.826606.The past decade has seen significant technological advance in the observation of trace gas fluxes over the open ocean, most notably CO2, but also an impressive list of other gases. Here we will emphasize flux observations from the air-side of the interface including both turbulent covariance (direct) and surface-layer similarity-based (indirect) bulk transfer velocity methods. Most applications of direct covariance observations have been from ships but recently work has intensified on buoy-based implementation. The principal use of direct methods is to quantify empirical coefficients in bulk estimates of the gas transfer velocity. Advances in direct measurements and some recent field programs that capture a considerable range of conditions with wind speeds exceeding 20 ms-1 are discussed. We use coincident direct flux measurements of CO2 and dimethylsulfide (DMS) to infer the scaling of interfacial viscous and bubble-mediated (whitecap driven) gas transfer mechanisms. This analysis suggests modest chemical enhancement of CO2 flux at low wind speed. We include some updates to the theoretical structure of bulk parameterizations (including chemical enhancement) as framed in the COAREG gas transfer algorithm.This work, and the contributions of MY and TB, is supported by the UK Natural Environment Research Council’s ORCHESTRA (Grant No. NE/N018095/1) and PICCOLO (Grant No. NE/P021409/1) projects, and by the European Space Agency’s AMT4OceanSatFlux project (Grant No. 4000125730/18/NL/FF/gp). CF and BB are funded by the National Oceanic and Atmospheric Administration’s Global Ocean Monitoring and Observing program (http://data.crossref.org/fundingdata/funder/10.13039/100018302). CZ was funded by the National Science Foundation (CJZ: OCE-2049579, Grants OCE-1537890 and OCE-1923935). Funding for HiWinGS was provided by the US National Science Foundation grant AGS-1036062. The Knorr-11 and SOAP campaigns were supported by the NSF Atmospheric Chemistry Program (Grant No. ATM-0426314, AGS-08568, -0851472, -0851407 and -1143709)
Dynein-dependent collection of membranes defines the architecture and position of microtubule asters in isolated, geometrically confined volumes of cell-free extracts
Full text link© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Sami, A. B., & Gatlin, J. C. Dynein-dependent collection of membranes defines the architecture and position of microtubule asters in isolated, geometrically confined volumes of cell-free extracts. Molecular Biology of the Cell, 33(11), (2022): mbcE22030074, https://doi.org/10.1091/mbc.E22-03-0074.It is well established that changes in the underlying architecture of the cell’s microtubule (MT) network can affect organelle organization within the cytoplasm, but it remains unclear whether the spatial arrangement of organelles reciprocally influences the MT network. Here we use a combination of cell-free extracts and hydrogel microenclosures to characterize the relationship between membranes and MTs during MT aster centration. We found that initially disperse ER membranes are collected by the aster and compacted near its nucleating center, all while the whole ensemble moves toward the geometric center of its confining enclosure. Once there, aster MTs adopt a bull’s-eye pattern with a high-density annular ring of MTs surrounding the compacted membrane core of lower MT density. Formation of this pattern was inhibited when dynein-dependent transport was perturbed or when membranes were depleted from the extracts. Asters in membrane-depleted extracts were able to move away from the most proximal wall but failed to center in cylindrical enclosures with diameters greater than or equal to 150 µm. Taken as whole, our data suggest that the dynein-dependent transport of membranes buttresses MTs near the aster center and that this plays an important role in modulating aster architecture and position.This work was made possible by an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences (NIGMS) of the National Institutes of Health (Grant #2P20GM103432). It was also supported by additional funding provided by the NIGMS (Grant #R01GM135568), the Biomedical Scholars program of the Pew Charitable Trusts, and the Marine Biological Laboratory Whitman Center