Topics and trends in NSF ocean sciences awards

Author Posting. © The Oceanography Society, 2018. This article is posted here by permission of The Oceanography Society for personal use, not for redistribution. The definitive version was published in Topics and trends in NSF ocean sciences awards. Oceanography 31(4), (2018): 164-170. doi:10.5670/oceanog.2018.404.The National Science Foundation Ocean Sciences Division (NSF-OCE) provides the majority of the support for ocean research in the United States. Knowledge of the trends in research and funding for NSF-OCE awards is important to investigators, academic institutions, policy analysts, and advocacy organizations. Here, we apply topic modeling to NSF-OCE award abstracts to uncover underlying research topics, examine the interrelationships between awards, and identify research and funding trends. The 20 topics identified by the model capture NSF-OCE’s 10 largest programs (~90% of awards) remarkably well and provide better resolution into research subjects. The distribution of awards in topic space shows how the different topics relate to each other based on their similarity and how awards transition from one topic to another. Awards have become more interdisciplinary over time, with increasing trends in 13 of the 20 topics (65%). Seven topics show a growing fraction of the number of awards while six topics have a declining share. Both the annual inflation-adjusted amount of money awarded and the fraction of the annual funding have been increasing over time in four of the 20 topics. Three other topics show a decline in both the annual amount awarded and the fraction of total annual funding. The identified topics can be grouped into three major themes: infrastructure, education, and science. After 2011, increases in the mean annual cost per project result in a relatively constant fraction of annual funding for infrastructure, despite a significant decline in the infrastructure fraction of awards. The information presented on research and funding trends is useful to scientists and academic institutions in planning and decision-making, while the metrics we employed can be used by NSF to quantify the effects of policy decisions.We thank T. Horner, B. Peucker-Ehrenbrink, K. Buesseler and M. Kurz for discussions and comments, the Woods Hole Oceanographic Institution Department of Marine Chemistry and Geochemistry for support, and A. Mix and three anonymous reviewers for their comments and suggestions. NSF deserves special credit for making its data publicly available

Gender differences in NSF ocean sciences awards

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Lima, I.D., Rheuban, J.E. Gender differences in NSF ocean sciences awards. Oceanography 34(4), (2021), https://doi.org/10.5670/oceanog.2021.401.In this study, we examine how women’s representation in National Science Foundation Ocean Sciences (NSF-OCE) awards changed between 1987 and 2019 and how it varied across different programs, research topics, and award types. Women’s participation in NSF-OCE awards increased at a rate of approximately 0.6% per year from about 10% in 1987 to 30% in 2019, and the strong similarity between the temporal trends in the NSF-OCE awards and the academic workforce suggests that there was no gender bias in NSF funding throughout the 33-year study period. The programs, topics, and award types related to education showed the strongest growth, achieving and surpassing parity with men, while those related to the acquisition of shared instrumentation and equipment for research vessels had the lowest women’s representation and showed relatively little change over time. Despite being vastly outnumbered by men, women principal investigators (PIs) tended to do more collaborative work and had a more diversified “portfolio” of research and research-related activities than men. We also found no evidence of gender bias in the amount awarded to men and women PIs during the study period. These results show that, despite significant increases in women’s participation in oceanography over the past three decades, women have still not reached parity with men. Although there appears to be no gender bias in funding decisions or amount awarded, there are significant differences between women’s participation in specific research subject areas that may reflect overall systemic biases in oceanography and academia more broadly. These results highlight areas where further investment is needed to improve women’s representation

Implications of future northwest Atlantic bottom temperatures on the American lobster (Homarus americanus) fishery

© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Journal of Geophysical Research: Oceans 122 (2017): 9387–9398, doi:10.1002/2017JC012949.Sea surface temperatures of the northwest Atlantic have warmed dramatically over the last several decades, while benthic temperatures have increased at a slower pace. Here we analyze a subset of the CMIP5 global Earth system model ensemble using a statistical downscaling approach to determine potential future changes in benthic temperatures on the northwest Atlantic continental shelf and slope (<500 m). We put future changes in the context of possible impacts of ocean warming on the high-value, wild-caught American Lobster (Homarus americanus) fishery. Future bottom temperatures of the northwest Atlantic under a business-as-usual (RCP8.5) and a climate-policy (RCP4.5) scenario are projected to increase by 0–1.5°C and 1.2–2.4°C by 2050 and 0–1.9°C and 2.3–4.3°C by the end of the century for RCP4.5 and RCP8.5, respectively. H. americanus experiences thermal stress at temperatures above 20°C, and projected increases in temperature is likely to result in changes in the distribution of optimal thermal egg hatching and settlement indicators. Inshore regions of southern New England, where H. americanus biomass and catch have been declining historically, will likely become inhospitable under either future scenario, while thermal egg hatching and settlement indicators will expand offshore and in the Gulf of Maine. These changes imply that members of the fishery based in southern New England may need to recapitalize to larger vessels to prepare for potential changes brought on by future climate warming. Results from the downscaling presented here can be useful in preparing for potential changes to other fisheries or in future climate vulnerability analyses.John D. and Catherine T. MacArthur Foundation Grant Number: 14-106159-000-CFP; NASA Grant Number: NNX14AP62A; “National Marine Sanctuaries as Sentinel Sites for a Demonstration Marine Biodiversity Observation Network (MBON)”; National Ocean Partnership Program Grant Number: NOPP RFP NOAA-NOS IOOS-2014-2003803; NOAA Integrated Ocean Observing System (IOOS) Program Offic

Evaluating benthic flux measurements from a gradient flux system

© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Coogan, J., Rheuban, J., & Long, M. Evaluating benthic flux measurements from a gradient flux system. Limnology and Oceanography: Methods, 20, (2022): 222-232, https://doi.org/10.1002/lom3.10482.Multiple methods exist to measure the benthic flux of dissolved oxygen (DO), but many are limited by short deployments and provide only a snapshot of the processes occurring at the sediment–water interface. The gradient flux (GF) method measures near bed gradients of DO and estimates the eddy diffusivity from existing turbulence closure methods to solve for the benthic flux. This study compares measurements at a seagrass, reef, and sand environment with measurements from two other methods, eddy covariance and benthic chambers, to highlight the strengths, weaknesses, and uncertainty of measurements being made. The results show three major areas of primary importance when using the GF method: (1) a sufficient DO gradient is critical to use this method and is limited by the DO sensor precision and gradient variability; (2) it is important to use similar methods when comparing across sites or time, as many of the methods showed good agreement but were often biased larger or smaller based on the method; and (3) in complex bottom types, estimates of the length scale and placement of the DO sensors can lead to large sources of error. Careful consideration of these potential errors is needed when using the GF method, but when properly addressed, this method showed high agreement with the other methods and may prove a useful tool for measuring long-term benthic fluxes of DO or other chemical sensors or constituents of interest that are incompatible with other methods.This work was supported by NSF OCE grants 1657727 and 2023069

Assessing the Impact of Local and Regional Influences on Nitrogen Loads to Buzzards Bay, MA

Nitrogen and chlorophyll-a concentrations in estuarine systems often correlate positively with increased nitrogen input. To determine the interactions between nitrogen load, physical drivers, and water quality indicators, we estimated nitrogen inputs to 28 estuaries within the Buzzards Bay, Massachusetts (USA) watershed from 1985 to 2013. Estimates were derived by combining parcel specific wastewater disposal, point source wastewater discharge, land use, and atmospheric nitrogen deposition data with a previously verified nitrogen loading model. Linear regression analysis was used to quantify temporal trends in individual data sets and characterize relationships between variables. The land-use data indicated that fractional coverage of impervious surfaces increased with time for all sub-watersheds at the expense of vegetation and agriculture land use classes, reflecting a growth in residential unit density. Nitrogen loads decreased with time for most watersheds on the western side of Buzzards Bay, reflecting decreased atmospheric nitrogen deposition combined with management efforts to mitigate wastewater pollution. For most of Buzzards Bay\u27s eastern watersheds, increases in nitrogen sourced from wastewater, driven primarily by the development of homes with on-site wastewater disposal, resulted in stable or overall nitrogen load increases. The relationship between nitrogen load and mean summer in situ chlorophyll a underwent a shift to more chlorophyll a per unit nitrogen input over time that was partially correlated to climatic variables such as increased precipitation and warming water column temperatures

Thirty-three years of ocean benthic warming along the U.S. Northeast Continental Shelf and Slope : patterns, drivers, and ecological consequences

© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Journal of Geophysical Research: Oceans 122 (2017): 9399–9414, doi:10.1002/2017JC012953.The U.S. Northeast Continental Shelf is experiencing rapid warming, with potentially profound consequences to marine ecosystems. While satellites document multiple scales of spatial and temporal variability on the surface, our understanding of the status, trends, and drivers of the benthic environmental change remains limited. We interpolated sparse benthic temperature data along the New England Shelf and upper Slope using a seasonally dynamic, regionally specific multiple linear regression model that merged in situ and remote sensing data. The statistical model predicted nearly 90% of the variability of the data, resulting in a synoptic time series spanning over three decades from 1982 to 2014. Benthic temperatures increased throughout the domain, including in the Gulf of Maine. Rates of benthic warming ranged from 0.1 to 0.4°C per decade, with fastest rates occurring in shallow, nearshore regions and on Georges Bank, the latter exceeding rates observed in the surface. Rates of benthic warming were up to 1.6 times faster in winter than the rest of the year in many regions, with important implications for disease occurrence and energetics of overwintering species. Drivers of warming varied over the domain. In southern New England and the mid-Atlantic shallow Shelf regions, benthic warming was tightly coupled to changes in SST, whereas both regional and basin-scale changes in ocean circulation affect temperatures in the Gulf of Maine, the Continental Shelf, and Georges Banks. These results highlight data gaps, the current feasibility of prediction from remotely sensed variables, and the need for improved understanding on how climate may affect seasonally specific ecological processes.John D. and Catherine T. MacArthur Foundation Grant Number: 14–106159-000-CFP; National Aeronautics and Space Administration Grant Number: NNX14AP62

Closing the Oxygen Mass Balance in Shallow Coastal Ecosystems

The oxygen concentration in marine ecosystems is influenced by production and consumption in the water column and fluxes across both the atmosphere-water and benthic-water boundaries. Each of these fluxes has the potential to be significant in shallow ecosystems due to high fluxes and low water volumes. This study evaluated the contributions of these three fluxes to the oxygen budget in two contrasting ecosystems, a Zostera marina (eelgrass) meadow in Virginia, U.S.A., and a coral reef in Bermuda. Benthic oxygen fluxes were evaluated by eddy covariance. Water column oxygen production and consumption were measured using an automated water incubation system. Atmosphere-water oxygen fluxes were estimated by parameterizations based on wind speed or turbulent kinetic energy dissipation rates. We observed significant contributions of both benthic fluxes and water column processes to the oxygen mass balance, despite the often-assumed dominance of the benthic communities. Water column rates accounted for 45% and 58% of the total oxygen rate, and benthic fluxes accounted for 23% and 39% of the total oxygen rate in the shallow (~ 1.5 m) eelgrass meadow and deeper (~ 7.5 m) reef site, respectively. Atmosphere-water fluxes were a minor component at the deeper reef site (3%) but a major component at the shallow eelgrass meadow (32%), driven by diel changes in the sign and strength of atmosphere-water gradient. When summed, the measured benthic, atmosphere-water, and water column rates predicted, with 85-90% confidence, the observed time rate of change of oxygen in the water column and provided an accurate, high temporal resolution closure of the oxygen mass balance

Closing the Oxygen Mass Balance in Shallow Coastal Ecosystems

The oxygen concentration in marine ecosystems is influenced by production and consumption in the water column and fluxes across both the atmosphere-water and benthic-water boundaries. Each of these fluxes has the potential to be significant in shallow ecosystems due to high fluxes and low water volumes. This study evaluated the contributions of these three fluxes to the oxygen budget in two contrasting ecosystems, a Zostera marina (eelgrass) meadow in Virginia, U.S.A., and a coral reef in Bermuda. Benthic oxygen fluxes were evaluated by eddy covariance. Water column oxygen production and consumption were measured using an automated water incubation system. Atmosphere-water oxygen fluxes were estimated by parameterizations based on wind speed or turbulent kinetic energy dissipation rates. We observed significant contributions of both benthic fluxes and water column processes to the oxygen mass balance, despite the often-assumed dominance of the benthic communities. Water column rates accounted for 45% and 58% of the total oxygen rate, and benthic fluxes accounted for 23% and 39% of the total oxygen rate in the shallow (~ 1.5 m) eelgrass meadow and deeper (~ 7.5 m) reef site, respectively. Atmosphere-water fluxes were a minor component at the deeper reef site (3%) but a major component at the shallow eelgrass meadow (32%), driven by diel changes in the sign and strength of atmosphere-water gradient. When summed, the measured benthic, atmosphere-water, and water column rates predicted, with 85-90% confidence, the observed time rate of change of oxygen in the water column and provided an accurate, high temporal resolution closure of the oxygen mass balance

Quantifying the effects of commercial clam aquaculture on C and N cycling : an integrated ecosystem approach

Author Posting. © The Author(s), 2016. This is the author's version of the work. It is posted here by permission of Coastal and Estuarine Research Federation for personal use, not for redistribution. The definitive version was published in Estuaries and Coasts 39 (2016): 1746–1761, doi: 10.1007/s12237-016-0106-0.Increased interest in using bivalve cultivation to mitigate eutrophication requires a comprehensive understanding of the net carbon (C) and nitrogen (N) budgets associated with cultivation on an ecosystem scale. This study quantified C and N processes related to clam (Mercenaria mercenaria) aquaculture in a shallow coastal environment (Cherrystone Inlet, VA) where the industry has rapidly increased. Clam physiological rates were compared with basin-wide ecosystem fluxes including primary production, benthic nutrient regeneration, and respiration. Although clam beds occupy only 3% of the ecosystem’s surface area, clams filtered 7-44% of the system’s volume daily, consumed an annual average of 103% of the phytoplankton production, creating a large flux of particulate C and N to the sediments. Annually, N regenerated and C respired by clam and microbial metabolism in clam beds were ~3-fold and ~1.5-fold higher, respectively, than N and C removed through harvest. Due to the short water residence time, the low watershed load, and the close vicinity of clam beds to the mouth of Cherrystone Inlet, cultivated clams are likely subsidized by phytoplankton from the Chesapeake Bay. Consequently, much of the N released by mineralization associated with clam cultivation is ‘new’ N as it would not be present in the system without bivalve facilitation. Macroalgae that are fueled by the enhanced N regeneration from clams represents a eutrophying process resulting from aquaculture. This synthesis demonstrates the importance of considering impacts of bivalve aquaculture in an ecosystem context especially relative to the potential of bivalves to remove nutrients and enhance C sinks.This work was supported by Virginia Sea Grant (NA10OAR4170085, #R/71515W, #R/715168), the NSF GK12 Fellowship (DGE-0840804), the Strategic Environmental Research and Development Program – Defense Coastal/Estuarine Research Program Project SI-1413, and NSF Virginia Coast Reserve LTER Project (DEB 0080381, DEB 0621014).2017-05-1

Capturing coastal water clarity variability with Landsat 8

© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Luis, K. M. A., Rheuban, J. E., Kavanaugh, M. T., Glover, D. M., Wei, J., Lee, Z., & Doney, S. C. Capturing coastal water clarity variability with Landsat 8. Marine Pollution Bulletin, 145, (2019): 96-104, doi: 10.1016/j.marpolbul.2019.04.078.Coastal water clarity varies at high temporal and spatial scales due to weather, climate, and human activity along coastlines. Systematic observations are crucial to assessing the impact of water clarity change on aquatic habitats. In this study, Secchi disk depths (ZSD) from Boston Harbor, Buzzards Bay, Cape Cod Bay, and Narragansett Bay water quality monitoring organizations were compiled to validate ZSD derived from Landsat 8 (L8) imagery, and to generate high spatial resolution ZSD maps. From 58 L8 images, acceptable agreement was found between in situ and L8 ZSD in Buzzards Bay (N = 42, RMSE = 0.96 m, MAPD = 28%), Cape Cod Bay (N = 11, RMSE = 0.62 m, MAPD = 10%), and Narragansett Bay (N = 8, RMSE = 0.59 m, MAPD = 26%). This work demonstrates the value of merging in situ ZSD with high spatial resolution remote sensing estimates for improved coastal water quality monitoring.This work was supported by the John D. and Catherine T. MacArthur Foundation (grant 14-106159-000-CFP) and by the National Science Foundation grant DGE 1249946, Integrative Graduate Education and Research Traineeship (IGERT): Coasts and Communities – Natural and Human Systems in Urbanizing Environments. Lastly, we are indebted to the Massachusetts Water Resources Authority, Buzzards Bay Coalition, Provincetown Center for Coastal Studies, Narragansett Bay Commission, and the numerous citizen scientists responsible for collecting the in situ measurements used in this study. Comments and suggestions from our anonymous reviewer were greatly appreciated