Jakuba Rachel W.

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Jakuba
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Rachel W.
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  • Article
    Quantifying the effects of nutrient enrichment and freshwater mixing on coastal ocean acidification
    (American Geophysical Union, 2019-11-07) Rheuban, Jennie E. ; Doney, Scott C. ; McCorkle, Daniel C. ; Jakuba, Rachel W.
    The U.S. Northeast is vulnerable to ocean and coastal acidification because of low alkalinity freshwater discharge that naturally acidifies the region, and high anthropogenic nutrient loads that lead to eutrophication in many estuaries. This study describes a combined nutrient and carbonate chemistry monitoring program in five embayments of Buzzards Bay, Massachusetts to quantify the effects of nutrient loading and freshwater discharge on aragonite saturation state (Ω). Monitoring occurred monthly from June 2015 to September 2017 with higher frequency at two embayments (Quissett and West Falmouth Harbors) and across nitrogen loading and freshwater discharge gradients. The more eutrophic stations experienced seasonal aragonite undersaturation, and at one site, nearly every measurement collected was undersaturated. We present an analytical framework to decompose variability in aragonite Ω into components driven by temperature, salinity, freshwater endmember mixing, and biogeochemical processes. We observed strong correlations between apparent oxygen utilization and the portion of aragonite Ω variation that we attribute to biogeochemistry. The regression slopes were consistent with Redfield ratios of dissolved inorganic carbon and total alkalinity to dissolved oxygen. Total nitrogen and the contribution of biogeochemical processes to aragonite Ω were highly correlated, and this relationship was used to estimate the likely effects of nitrogen loading improvements on aragonite Ω. Under nitrogen loading reduction scenarios, aragonite Ω in the most eutrophic estuaries could be raised by nearly 0.6 units, potentially increasing several stations above the critical threshold of 1. This analysis provides a quantitative framework for incorporating ocean and coastal acidification impacts into regulatory and management discussions.
  • Article
    Evidence for the linked biogeochemical cycling of zinc, cobalt, and phosphorus in the western North Atlantic Ocean
    (American Geophysical Union, 2008-11-22) Jakuba, Rachel W. ; Moffett, James W. ; Dyhrman, Sonya T.
    Many trace metals such as iron, copper, and manganese have lower concentrations in the surface waters of the North Pacific Ocean than in North Atlantic surface waters. However, cobalt and zinc concentrations in North Atlantic surface waters are often as low as those reported in the North Pacific. We studied the relationship between the distribution of cobalt, zinc, and phosphorus in surface waters of the western North Atlantic Ocean. Both metals show strong depletion in the southern Sargasso Sea, a region characterized by exceedingly low dissolved inorganic phosphorus (generally <4 nmol L−1) and measurable alkaline phosphatase activity. Alkaline phosphatase is a metalloenzyme (typically containing zinc) that cleaves phosphate monoesters and is a diagnostic indicator of phosphorus stress in phytoplankton. In contrast to the North Pacific Ocean, cobalt and zinc appear to be drawn down to their lowest values only when inorganic phosphorus is below 10 nmol L−1 in the North Atlantic Ocean. Lower levels of phosphorus in the Atlantic may contribute to these differences, possibly through an increased biological demand for zinc and cobalt associated with dissolved organic phosphorus acquisition. This hypothesis is consistent with results of a culture study where alkaline phosphatase activity decreased in the model coccolithophore Emiliania huxleyi upon zinc and cobalt limitation.
  • Article
    Dissolved zinc in the subarctic North Pacific and Bering Sea : its distribution, speciation, and importance to primary producers
    (American Geophysical Union, 2012-05-12) Jakuba, Rachel W. ; Saito, Mak A. ; Moffett, James W. ; Xu, Yan
    The eastern subarctic North Pacific, an area of high nutrients and low chlorophyll, has been studied with respect to the potential for iron to control primary production. The geochemistry of zinc, a critical micronutrient for diatoms, is less well characterized. Total zinc concentrations and zinc speciation were measured in near-surface waters on transects across the subarctic North Pacific and across the Bering Sea. Total dissolved zinc concentrations in the near-surface ranged from 0.10 nmol L−1 to 1.15 nmol L−1 with lowest concentrations in the eastern portions of both the North Pacific and Bering Sea. Dissolved zinc speciation was dominated by complexation to strong organic ligands whose concentration ranged from 1.1 to 3.6 nmol L−1 with conditional stability constants (K′ZnL/Zn′) ranging from 109.3 to 1011.0. The importance of zinc to primary producers was evaluated by comparison to phytoplankton pigment concentrations and by performing a shipboard incubation. Zinc concentrations were positively correlated with two pigments that are characteristic of diatoms. At one station in the North Pacific, the addition of 0.75 nmol L−1 zinc resulted in a doubling of chlorophyll after 4 days.
  • Article
    Water quality measurements in Buzzards Bay by the Buzzards Bay Coalition Baywatchers Program from 1992 to 2018
    (Nature Research, 2021-03-05) Jakuba, Rachel W. ; Williams, Tony ; Neill, Christopher ; Costa, Joseph E. ; McHorney, Richard ; Scott, Lindsay ; Howes, Brian L. ; Ducklow, Hugh W. ; Erickson, Matthew ; Rasmussen, Mark
    The Buzzards Bay Coalition’s Baywatchers Monitoring Program (Baywatchers) collected summertime water quality information at more than 150 stations around Buzzards Bay, Massachusetts from 1992 to 2018. Baywatchers documents nutrient-related water quality and the effects of nitrogen pollution. The large majority of stations are located in sub-estuaries of the main Bay, although stations in central Buzzards Bay and Vineyard Sound were added beginning in 2007. Measurements include temperature, salinity, Secchi depth and concentrations of dissolved oxygen, ammonium, nitrate + nitrite, total dissolved nitrogen, particulate organic nitrogen, particulate organic carbon, ortho-phosphate, chlorophyll a, pheophytin a, and in lower salinity waters, total phosphorus and dissolved organic carbon. The Baywatchers dataset provides a long-term record of the water quality of Buzzards Bay and its sub-estuaries. The data have been used to identify impaired waters, evaluate discharge permits, support the development of nitrogen total maximum daily loads, develop strategies for reducing nitrogen inputs, and increase public awareness and generate support for management actions to control nutrient pollution and improve water quality.
  • Article
    Spatial and temporal trends in summertime climate and water quality indicators in the coastal embayments of Buzzards Bay, Massachusetts
    (Copernicus Publications on behalf of the European Geosciences Union, 2016-01-15) Rheuban, Jennie E. ; Williamson, Shanna ; Costa, Joseph E. ; Glover, David M. ; Jakuba, Rachel W. ; McCorkle, Daniel C. ; Neill, Christopher ; Williams, Tony ; Doney, Scott C.
    Degradation of coastal ecosystems by eutrophication is largely defined by nitrogen loading from land via surface water and groundwater flows. However, indicators of water quality are highly variable due to a myriad of other drivers, including temperature and precipitation. To evaluate these drivers, we examined spatial and temporal trends in a 22-year record of summer water quality data from 122 stations in 17 embayments within Buzzards Bay, MA (USA), collected through a citizen science monitoring program managed by Buzzards Bay Coalition. To identify spatial patterns across Buzzards Bay's embayments, we used a principle component and factor analysis and found that rotated factor loadings indicated little correlation between inorganic nutrients and organic matter or chlorophyll a (Chl a) concentration. Factor scores showed that embayment geomorphology in addition to nutrient loading was a strong driver of water quality, where embayments with surface water inputs showed larger biological impacts than embayments dominated by groundwater influx. A linear regression analysis of annual summertime water quality indicators over time revealed that from 1992 to 2013, most embayments (15 of 17) exhibited an increase in temperature (mean rate of 0.082 ± 0.025 (SD) °C yr−1) and Chl a (mean rate of 0.0171 ± 0.0088 log10 (Chl a; mg m−3) yr−1, equivalent to a 4.0 % increase per year). However, only seven embayments exhibited an increase in total nitrogen (TN) concentration (mean rate 0.32 ± 0.47 (SD) µM yr−1). Average summertime log10(TN) and log10(Chl a) were correlated with an indication that the yield of Chl a per unit total nitrogen increased with time suggesting the estuarine response to TN may have changed because of other stressors such as warming, altered precipitation patterns, or changing light levels. These findings affirm that nitrogen loading and physical aspects of embayments are essential in explaining the observed ecosystem response. However, climate-related stressors may also need to be considered by managers because increased temperature and precipitation may worsen water quality and partially offset benefits achieved by reducing nitrogen loading.
  • Dataset
    Buzzards Bay Water Quality Data from the Buzzards Bay Coalition’s Baywatchers Program 1992-2018 August 2020 version
    (Woods Hole Oceanographic Institution, 2020-08-28) Jakuba, Rachel W. ; Williams, Tony ; Neill, Christopher ; Costa, Joseph E. ; McHorney, Richard ; Scott, Lindsay ; Howes, Brian L. ; Ducklow, Hugh W. ; Erickson, Matthew ; Rasmussen, Mark
    The Buzzards Bay Coalition’s Baywatchers Monitoring Program collected summertime water quality information at more than 150 stations around Buzzards Bay, Massachusetts from 1992 to 2018. Baywatchers monitoring data document nutrient-related water quality and the effects of nitrogen pollution. The large majority of stations are located in sub-estuaries of the main Bay, although stations in central Buzzards Bay and Vineyard Sound were added beginning in 2007. Measurements include temperature, salinity, Secchi depth and concentrations of dissolved oxygen, ammonium, nitrate + nitrite, total dissolved nitrogen, particulate organic nitrogen, particulate organic carbon, ortho-phosphate, chlorophyll a, pheophytin a, and in lower salinity waters, total phosphorus and dissolved organic carbon. The Baywatchers dataset provides a long-term record of the water quality of Buzzards Bay and its sub-estuaries. The data have been used to identify impaired waters, evaluate discharge permits, support the development of nitrogen total maximum daily loads, develop strategies for reducing nitrogen inputs, and increase public awareness and generate support for management actions to control nutrient pollution and improve water quality. The Readme, STN_EQUIV, Stations and Methods, S_D for WFH, and Acknowledge tabs were updated and corrections were made for Time and POC on 2018 Upper Bay samples and deleted CH1 from sonde method column where no CHL data existed, moved words like "sample lost" from Chl and Pheo data columns to comments column.
  • Dataset
    Buzzards Bay Water Quality Data from the Buzzards Bay Coalition’s Baywatchers Program 1992-2020
    (Woods Hole Oceanographic Institution, 2021-07-09) Jakuba, Rachel W. ; Williams, Tony ; Neill, Christopher ; Costa, Joseph E. ; McHorney, Richard ; Scott, Lindsay ; Howes, Brian L. ; Ducklow, Hugh W. ; Erickson, Matthew ; Rasmussen, Mark
    The Buzzards Bay Coalition’s Baywatchers Monitoring Program collected summertime water quality information at more than 150 stations around Buzzards Bay, Massachusetts from 1992 to 2020. Baywatchers monitoring data document nutrient-related water quality and the effects of nitrogen pollution. The large majority of stations are located in sub-estuaries of the main Bay, although stations in central Buzzards Bay and Vineyard Sound were added beginning in 2007. Measurements include temperature, salinity, Secchi depth and concentrations of dissolved oxygen, ammonium, nitrate + nitrite, total dissolved nitrogen, particulate organic nitrogen, particulate organic carbon, ortho-phosphate, chlorophyll a, pheophytin a, and in lower salinity waters, total phosphorus and dissolved organic carbon. The Baywatchers dataset provides a long-term record of the water quality of Buzzards Bay and its sub-estuaries. The data have been used to identify impaired waters, evaluate discharge permits, support the development of nitrogen total maximum daily loads, develop strategies for reducing nitrogen inputs, and increase public awareness and generate support for management actions to control nutrient pollution and improve water quality. The Readme, STN_EQUIV, Stations and Methods, S_D for WFH, and Acknowledge tabs were updated and corrections were made for Time and POC on 2018 Upper Bay samples and deleted CH1 from sonde method column where no CHL data existed, moved words like "sample lost" from Chl and Pheo data columns to comments column.
  • Dataset
    Buzzards Bay Water Quality Data from the Buzzards Bay Coalition’s Baywatchers Program 2021-2023
    (Woods Hole Oceanographic Institution, 2025-01-15) Jakuba, Rachel W. ; Williams, Tony ; Neill, Christopher ; Costa, Joseph E. ; McHorney, Richard ; Scott, Lindsay ; Howes, Brian L. ; Ducklow, Hugh W. ; Erickson, Matthew ; Rasmussen, Mark
    The Buzzards Bay Coalition’s Baywatchers Monitoring Program collected summertime water quality information at more than 150 stations around Buzzards Bay, Massachusetts from 1992 to 2023. Baywatchers monitoring data document nutrient-related water quality and the effects of nitrogen pollution. The large majority of stations are located in sub-estuaries of the main Bay, although stations in central Buzzards Bay and Vineyard Sound were added beginning in 2007. Measurements include temperature, salinity, Secchi depth and concentrations of dissolved oxygen, ammonium, nitrate + nitrite, total dissolved nitrogen, particulate organic nitrogen, particulate organic carbon, ortho-phosphate, chlorophyll a, pheophytin a, and in lower salinity waters, total phosphorus and dissolved organic carbon. The Baywatchers dataset provides a long-term record of the water quality of Buzzards Bay and its sub-estuaries. The data have been used to identify impaired waters, evaluate discharge permits, support the development of nitrogen total maximum daily loads, develop strategies for reducing nitrogen inputs, and increase public awareness and generate support for management actions to control nutrient pollution and improve water quality. The Readme, STN_EQUIV, Stations and Methods, S_D for WFH, and Acknowledge tabs were updated and corrections were made for Time and POC on 2018 Upper Bay samples and deleted CH1 from sonde method column where no CHL data existed, moved words like "sample lost" from Chl and Pheo data columns to comments column.
  • Dataset
    Buzzards Bay Water Quality Data from the Buzzards Bay Coalition’s Baywatchers Program 1992-2018
    (Woods Hole Oceanographic Institution, 2020-05-04) Jakuba, Rachel W. ; Williams, Tony ; Neill, Christopher ; Costa, Joseph E. ; McHorney, Richard ; Scott, Lindsay ; Howes, Brian L. ; Ducklow, Hugh W. ; Erickson, Matthew ; Rasmussen, Mark
    The Buzzards Bay Coalition’s Baywatchers Monitoring Program collected summertime water quality information at more than 150 stations around Buzzards Bay, Massachusetts from 1992 to 2018. Baywatchers monitoring data document nutrient-related water quality and the effects of nitrogen pollution. The large majority of stations are located in sub-estuaries of the main Bay, although stations in central Buzzards Bay and Vineyard Sound were added beginning in 2007. Measurements include temperature, salinity, Secchi depth and concentrations of dissolved oxygen, ammonium, nitrate + nitrite, total dissolved nitrogen, particulate organic nitrogen, particulate organic carbon, ortho-phosphate, chlorophyll a, pheophytin a, and in lower salinity waters, total phosphorus and dissolved organic carbon. The Baywatchers dataset provides a long-term record of the water quality of Buzzards Bay and its sub-estuaries. The data have been used to identify impaired waters, evaluate discharge permits, support the development of nitrogen total maximum daily loads, develop strategies for reducing nitrogen inputs, and increase public awareness and generate support for management actions to control nutrient pollution and improve water quality.
  • Dataset
    Buzzards Bay Water Quality Data from the Buzzards Bay Coalition’s Baywatchers Program 1992-2018 December 2020 version
    (Woods Hole Oceanographic Institution, 2020-12-08) Jakuba, Rachel W. ; Williams, Tony ; Neill, Christopher ; Costa, Joseph E. ; McHorney, Richard ; Scott, Lindsay ; Howes, Brian L. ; Ducklow, Hugh W. ; Erickson, Matthew ; Rasmussen, Mark
    The Buzzards Bay Coalition’s Baywatchers Monitoring Program collected summertime water quality information at more than 150 stations around Buzzards Bay, Massachusetts from 1992 to 2018. Baywatchers monitoring data document nutrient-related water quality and the effects of nitrogen pollution. The large majority of stations are located in sub-estuaries of the main Bay, although stations in central Buzzards Bay and Vineyard Sound were added beginning in 2007. Measurements include temperature, salinity, Secchi depth and concentrations of dissolved oxygen, ammonium, nitrate + nitrite, total dissolved nitrogen, particulate organic nitrogen, particulate organic carbon, ortho-phosphate, chlorophyll a, pheophytin a, and in lower salinity waters, total phosphorus and dissolved organic carbon. The Baywatchers dataset provides a long-term record of the water quality of Buzzards Bay and its sub-estuaries. The data have been used to identify impaired waters, evaluate discharge permits, support the development of nitrogen total maximum daily loads, develop strategies for reducing nitrogen inputs, and increase public awareness and generate support for management actions to control nutrient pollution and improve water quality. The Readme, STN_EQUIV, Stations and Methods, S_D for WFH, and Acknowledge tabs were updated and corrections were made for Time and POC on 2018 Upper Bay samples and deleted CH1 from sonde method column where no CHL data existed, moved words like "sample lost" from Chl and Pheo data columns to comments column.