Berelson William M.

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Berelson

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William M.

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Eastern Tropical South Pacific Nitrogen fixation

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2015-04-16) Knapp, Angela ; Casciotti, Karen L. ; Berelson, William M. ; Prokopenko, Maria ; Capone, Douglas

An extensive region of the Eastern Tropical South Pacific (ETSP) Ocean has surface waters that are nitrate-poor yet phosphate-rich. It has been proposed that this distribution of surface nutrients provides a geochemical niche favorable for N2 fixation, the primary source of nitrogen to the ocean. Here, we present results from two cruises to the ETSP where rates of N2 fixation and its contribution to export production were determined with a suite of geochemical and biological measurements. N2 fixation was only detectable using nitrogen isotopic mass balances at two of six stations, and rates ranged from 0 to 23 µmol N m-2 d-1 based on sediment trap fluxes. Whereas the fractional importance of N2 fixation did not change, the N2-fixation rates at these two stations were several-fold higher when scaled to other productivity metrics. Regardless of the choice of productivity metric these N2-fixation rates are low compared with other oligotrophic locations, and the nitrogen isotope budgets indicate that N2 fixation supports no more than 20% of export production regionally. Although euphotic zone-integrated short-term N2-fixation rates were higher, up to 100 µmol N m-2 d-1, and detected N2 fixation at all six stations, studies of nitrogenase gene abundance and expression from the same cruises align with the geochemical data and together indicate that N2 fixation is a minor source of new nitrogen to surface waters of the ETSP. This finding is consistent with the hypothesis that, despite a relative abundance of phosphate, iron may limit N2 fixation in the ETSP.
Processed CTD data from cruises R/V Atlantis (AT15-61) in Jan-Feb 2010 and R/V Melville (MV1104) in Mar-Apr 2011 in the Eastern Tropical South Pacific

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2021-05-07) Casciotti, Karen L. ; Capone, Douglas G. ; Santoro, Alyson E. ; Berelson, William M. ; Knapp, Angela N.

Processed CTD data from cruises R/V Atlantis (AT15-61) in Jan-Feb 2010 and R/V Melville (MV1104) in Mar-Apr 2011 in the Eastern Tropical South Pacific 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/827861
Suspended PIC, PC, PN data collected along a North Pacific transect between Hawaii and Alaska on R/V Kilo Moana cruise KM1712 in August 2017

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2021-09-23) Dong, Sijia ; Berelson, William M. ; Adkins, Jess F. ; Subhas, Adam V. ; Rollins, Nick E.

This dataset includes general measurements for in situ pump casts at 5 stations on a transect between Hawaii and Alaska. Data was collected in August 2017 onboard R/V Kilo Moana cruise KM1712. 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/860409
Depth profiles of dissolved O2 saturation and isotopologues from the R/V Yellowfin and R/V Kilo Moana from 2016-09-14 to 2017-08-28

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2019-12-05) Hu, Huanting ; Yeung, Laurence ; Berelson, William M. ; Young, Edward

Seawater was sampled from Niskin bottles associated with CTD casts on each cruise. Water for these dissolved gas isotope samples was the first to be sampled from a given Niskin bottle. When possible, bottles from the same cast were sampled, but depth profiles often came from separate casts at the same site. 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/753594
In situ experimentally determined dissolution rates of biogenic calcites along a North Pacific transect between Hawaii and Alaska (KM1712 expedition) in August 2017

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2022-08-03) Berelson, William M. ; Adkins, Jess F. ; Subhas, Adam V. ; Dong, Sijia ; Naviaux, John D.

This dataset includes biogenic and inorganic calcite and aragonite dissolution rates from the CDisK-IV cruise in the North Pacific Ocean, August 2017. We include niskin incubator alkalinity, pH, silicate, phosphate, and nitrate data, as well as calculated saturation state and dissolution rates. Rates are reported in units of g/g/day and also g/cm2/day, normalized by the specific surface areas of the materials used. Dissolution rates of inorganic aragonite and calcite, along with biogenic E. huxleyi liths, a planktic foraminifera assemblage, and a benthic foraminifera Amphistegina species, are provided, for 4 out of the 6 stations occupied on the cruise. 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/856409
Carbonate chemistry and CTD data collected along a North Pacific transect between Hawaii and Alaska on R/V Kilo Moana cruise KM1712 in August 2017

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2022-02-01) Dong, Sijia ; Liu, Xuewu ; Naviaux, John D. ; Subhas, Adam V. ; Rollins, Nick E. ; Adkins, Jess F. ; Berelson, William M.

This dataset includes carbonate chemistry and general measurements from CTD casts at 6 stations between Hawaii and Alaska. Data were collected in August 2017 onboard R/V Kilo Moana. 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/836954
Actinium and radium fluxes from the seabed in the northeast Pacific Basin

(Elsevier, 2022-10-22) Kemnitz, Nathaniel ; Hammond, Douglas E. ; Henderson, Paul ; Le Roy, Emilie ; Charette, Matthew ; Moore, Willard ; Anderson, Robert F. ; Fleisher, Martin Q. ; Leal, Anne ; Black, Erin ; Hayes, Christopher T. ; Adkins, Jess ; Berelson, William ; Bian, Xiaopeng

Five sediment cores were collected along a cruise tract from Hawaii to Alaska in August 2017 (C-Disk-IV cruise) with the objective of characterizing the behavior of 227Ac, 228Ra, and 226Ra and their fluxes into the overlying water column, information that is essential to the interpretation of the distribution of these tracers in the ocean, for example, as measured on GEOTRACES cruises. Solid phase profiles of these isotopes were measured, and reaction-transport models were applied that incorporated molecular diffusion, bioturbation, sedimentation, distribution coefficients (kd), and the fraction of each isotope released to pore water by parent decay (called F). Fits to these profiles used kd values determined in lab experiments for C-Disk-IV sediments. Ra kd values (1000–3000 mL g−1) agreed with previous estimates for deep-sea sediments, and Ac kd values (3500–22,000 mL g−1) correlated with those for Ra but were about 7 times greater. Two independent approaches were used to quantify the benthic fluxes of 227Ac and 228Ra in the Northeast Pacific: (1) use of solid phase profiles with a reaction-transport model, as well as integrated downcore daughter-parent deficiency; and (2) direct measurement of fluxes based on core incubation. The two independent methods agreed within uncertainty, and the average 227Ac and 228Ra sediment fluxes for the Northeast Pacific are 90 ± 20 and 600 ± 200 dpm m−2-yr−1, respectively. The 226Ra sediment flux was only determined by the former approach, and the flux calculated in this study is similar to previous work in the North Pacific, averaging 1300 ± 200 dpm m−2-yr−1. This is over 2× higher than the water column inventory of 226Ra in this region (600 dpm m−2-yr−1), and indicates the importance of lateral 226Ra export from the N. Pacific. The largest 227Ac and Ra isotope fluxes in the study area are near the center of the Northeast Pacific (∼37°N). Smaller 227Ac, 228Ra and 226Ra fluxes occur north of 40°N, primarily due to dilution of their Pa and Th ancestors by higher sediment accumulation rates.
Carbonate chemistry and CTD data collected along a North Pacific transect between Hawaii and Alaska on R/V Kilo Moana cruise KM1712 in August 2017

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2021-01-20) Dong, Sijia ; Liu, Xuewu ; Naviaux, John D. ; Subhas, Adam V. ; Rollins, Nick E. ; Adkins, Jess F. ; Berelson, William M.

This dataset includes carbonate chemistry and general measurements from CTD casts at 6 stations between Hawaii and Alaska. Data were collected in August 2017 onboard R/V Kilo Moana. 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/836954
Sinking PIC, PC in shallow sediment traps collected along a North Pacific transect between Hawaii and Alaska on R/V Kilo Moana cruise KM1712 in August 2017

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2021-09-23) Dong, Sijia ; Berelson, William M. ; Adkins, Jess F. ; Subhas, Adam V. ; Rollins, Nick E.

This dataset includes general measurements for sediment trap casts at 5 stations along a transect between Hawaii and Alaska. Data was collected in August 2017 onboard R/V Kilo Moana cruise KM1712. 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/860424
Shallow calcium carbonate cycling in the North Pacific Ocean

(American Geophysical Union, 2022-05-06) Subhas, Adam V. ; Dong, Sijia ; Naviaux, John D. ; Rollins, Nick E. ; Ziveri, Patrizia ; Gray, William R. ; Rae, James W. B. ; Liu, Xuewu ; Byrne, Robert H. ; Chen, Sang ; Moore, Christopher ; Martell-Bonet, Loraine ; Steiner, Zvi ; Antler, Gilad ; Hu, Huanting ; Lunstrum, Abby ; Hou, Yi ; Kemnitz, Nathaniel ; Stutsman, Johnny ; Pallacks, Sven ; Dugenne, Mathilde ; Quay, Paul D. ; Berelson, William M. ; Adkins, Jess F.

The cycling of biologically produced calcium carbonate (CaCO3) in the ocean is a fundamental component of the global carbon cycle. Here, we present experimental determinations of in situ coccolith and foraminiferal calcite dissolution rates. We combine these rates with solid phase fluxes, dissolved tracers, and historical data to constrain the alkalinity cycle in the shallow North Pacific Ocean. The in situ dissolution rates of coccolithophores demonstrate a nonlinear dependence on saturation state. Dissolution rates of all three major calcifying groups (coccoliths, foraminifera, and aragonitic pteropods) are too slow to explain the patterns of both CaCO3 sinking flux and alkalinity regeneration in the North Pacific. Using a combination of dissolved and solid-phase tracers, we document a significant dissolution signal in seawater supersaturated for calcite. Driving CaCO3 dissolution with a combination of ambient saturation state and oxygen consumption simultaneously explains solid-phase CaCO3 flux profiles and patterns of alkalinity regeneration across the entire N. Pacific basin. We do not need to invoke the presence of carbonate phases with higher solubilities. Instead, biomineralization and metabolic processes intimately associate the acid (CO2) and the base (CaCO3) in the same particles, driving the coupled shallow remineralization of organic carbon and CaCO3. The linkage of these processes likely occurs through a combination of dissolution due to zooplankton grazing and microbial aerobic respiration within degrading particle aggregates. The coupling of these cycles acts as a major filter on the export of both organic and inorganic carbon to the deep ocean.
Anaerobic diagenesis of silica and carbon in continental margin sediments : discrete zones of TCO2 production

( 2005-05-10) Berelson, William M. ; Prokopenko, Maria ; Sansone, F. J. ; Graham, A. W. ; McManus, Jerry F. ; Bernhard, Joan M.

Pore water profiles of dissolved Si, Ca2+, SO42-, CH4, and TCO2 (Dissolved Inorganic Carbon; DIC) were determined from multicores and gravity cores collected at nine sites off Southern California, the west coast of Mexico, and within the Gulf of California. These sites were located within the eastern North Pacific oxygen minimum zone at depths of 400 to 900 m and in settings where bottom water oxygen concentrations were <3 μM and sediments were laminated. Pore water profiles were defined at a resolution of millimeters (whole core squeezing), centimeters (sectioning and squeezing) and meters (gravity core sectioning and squeezing), and diffusive fluxes were calculated for different zones within the sediment column. The flux of dissolved silica across the sediment-water interface (SWI) ranged from 0.3 to 3.4 mmol Si m-2d-1, and TCO2 fluxes ranged from 0.8 to 4.6 mmol C m-2d-1. A positive correlation (r = 0.74) existed between these fluxes, yet these two constituents exhibited significantly different diagenetic behavior downcore; dissolved Si generally reached a constant concentration (between 450 and 900 μM) in the upper few cm, whereas TCO2 concentrations increased monotonically with depth. Methane was detected at micromolar levels in sediment intervals between 0 and 60 cm and at five sites, increased to millimolar levels at depths of 80 to 170 cm. At the horizon marking the appearance of millimolar levels of methane, there was a distinct change in slope of the sulfate and TCO2 gradients. A flux budget for this horizon was determined by using linear fits to pore water profiles; these budgets indicate that the upward TCO2 flux away from this horizon is 40 to 50% greater than the downward sulfate flux to this horizon. Given that the TCO2 flux to this horizon from below was quite small, this imbalance suggests that anaerobic oxidation of methane by sulfate is not the only process producing TCO2 within this horizon. A budget for TCO2 at this horizon is balanced when 40 to 80% of the sulfate flux is attributed to organic carbon remineralization. Of the DIC that diffuses across the SWI, 20 to 40% is generated by reactions occurring within or below this deep reaction horizon.
In situ experimentally determined dissolution rates of biogenic calcites along a North Pacific transect between Hawaii and Alaska (KM1712 expedition) in August 2017

(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2021-08-20) Berelson, William M. ; Adkins, Jess F. ; Subhas, Adam V. ; Dong, Sijia ; Naviaux, John D.

This dataset includes biogenic and inorganic calcite and aragonite dissolution rate data from the CDisK-IV cruise in the North Pacific Ocean, August 2017. We include niskin incubator alkalinity, pH, silicate, phosphate, and nitrate data, as well as calculated saturation state and dissolution rates. Rates are reported in units of g/g/day and also g/cm2/day, normalized by the specific surface areas of the materials used. Dissolution rates of inorganic aragonite and calcite, along with biogenic E. huxleyi liths, a planktic foraminifera assemblage, and a benthic foraminifera Amphistegina species, are provided, for 4 out of the 6 stations occupied on the cruise. 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/856409
Source to sink : evolution of lignin composition in the Madre de Dios River system with connection to the Amazon basin and offshore

(John Wiley & Sons, 2016-05-21) Feng, Xiaojuan ; Feakins, Sarah J. ; Liu, Zongguang ; Ponton, Camilo ; Wang, Renée Z. ; Karkabi, Elias ; Galy, Valier ; Berelson, William M. ; Nottingham, Andrew T. ; Meir, Patrick ; West, A. Joshua

While lignin geochemistry has been extensively investigated in the Amazon River, little is known about lignin distribution and dynamics within deep, stratified river channels or its transformations within soils prior to delivery to rivers. We characterized lignin phenols in soils, river particulate organic matter (POM), and dissolved organic matter (DOM) across a 4 km elevation gradient in the Madre de Dios River system, Peru, as well as in marine sediments to investigate the source-to-sink evolution of lignin. In soils, we found more oxidized lignin in organic horizons relative to mineral horizons. The oxidized lignin signature was maintained during transfer into rivers, and lignin was a relatively constant fraction of bulk organic carbon in soils and riverine POM. Lignin in DOM became increasingly oxidized downstream, indicating active transformation of dissolved lignin during transport, especially in the dry season. In contrast, POM accumulated undegraded lignin downstream during the wet season, suggesting that terrestrial input exceeded in-river degradation. We discovered high concentrations of relatively undegraded lignin in POM at depth in the lower Madre de Dios River in both seasons, revealing a woody undercurrent for its transfer within these deep rivers. Our study of lignin evolution in the soil-river-ocean continuum highlights important seasonal and depth variations of river carbon components and their connection to soil carbon pools, providing new insights into fluvial carbon dynamics associated with the transfer of lignin biomarkers from source to sink.
Pelagic calcium carbonate production and shallow dissolution in the North Pacific Ocean

(Nature Research, 2023-02-20) Ziveri, Patrizia ; Gray, William Robert ; Anglada-Ortiz, Griselda ; Manno, Clara ; Grelaud, Michael ; Incarbona, Alessandro ; Rae, James William Buchanan ; Subhas, Adam V. ; Pallacks, Sven ; White, Angelicque ; Adkins, Jess F. ; Berelson, William

Planktonic calcifying organisms play a key role in regulating ocean carbonate chemistry and atmospheric CO. Surprisingly, references to the absolute and relative contribution of these organisms to calcium carbonate production are lacking. Here we report quantification of pelagic calcium carbonate production in the North Pacific, providing new insights on the contribution of the three main planktonic calcifying groups. Our results show that coccolithophores dominate the living calcium carbonate (CaCO) standing stock, with coccolithophore calcite comprising ~90% of total CaCO production, and pteropods and foraminifera playing a secondary role. We show that pelagic CaCO production is higher than the sinking flux of CaCO at 150 and 200 m at ocean stations ALOHA and PAPA, implying that a large portion of pelagic calcium carbonate is remineralised within the photic zone; this extensive shallow dissolution explains the apparent discrepancy between previous estimates of CaCO production derived from satellite observations/biogeochemical modeling versus estimates from shallow sediment traps. We suggest future changes in the CaCO cycle and its impact on atmospheric CO will largely depend on how the poorly-understood processes that determine whether CaCO is remineralised in the photic zone or exported to depth respond to anthropogenic warming and acidification.
Authigenic Formation of Clay Minerals in the Abyssal North Pacific

(American Geophysical Union, 2022-11-02) Steiner, Zvi ; Rae, James W. B. ; Berelson, William M. ; Adkins, Jess F. ; Hou, Yi ; Dong, Sijia ; Lampronti, Giulio I. ; Liu, Xuewu ; Achterberg, Eric P. ; Subhas, Adam V. ; Turchyn, Alexandra V.

Present estimates of the biogeochemical cycles of calcium, strontium, and potassium in the ocean reveal large imbalances between known input and output fluxes. Using pore fluid, incubation, and solid sediment data from North Pacific multi‐corer cores we show that, contrary to the common paradigm, the top centimeters of abyssal sediments can be an active site of authigenic precipitation of clay minerals. In this region, clay authigenesis is the dominant sink for potassium and strontium and consumes nearly all calcium released from benthic dissolution of calcium carbonates. These observations support the idea that clay authigenesis occurring over broad regions of the world ocean may be a major buffer for ocean chemistry on the time scale of the ocean overturning circulation, and key to the long‐term stability of Earth's climate.Key PointsNorth Pacific red clay sediments are a sink for marine calcium, strontium, and potassiumAuthigenic formation of clay minerals is prevalent in pelagic sediments throughout the North PacificThe main mechanism for clay formation is recrystallization of aluminosilicates, neoformation can occur in biogenic silica rich sediments
Trace element geochemistry in North Pacific red clay sediment porewaters and implications for water‐column studies

(American Geophysical Union, 2023-11-14) Steiner, Zvi ; Antler, Gilad ; Berelson, William M. ; Crockford, Peter W. ; Dunlea, Ann G. ; Hou, Yi ; Adkins, Jess F. ; Turchyn, Alexandra V. ; Achterberg, Eric P.

Geochemical analyses of trace elements in the ocean water column have suggested that pelagic clay-rich sediments are a major source of various elements to bottom-waters. However, corresponding high-quality measurements of trace element concentrations in porewaters of pelagic clay-rich sediments are scarce, making it difficult to evaluate the contributions from benthic processes to global oceanic cycles of trace elements. To bridge this gap, we analyzed porewater and bulk sediment concentrations of vanadium, chromium, cobalt, nickel, copper, arsenic, molybdenum, barium and uranium, as well as concentrations of the major oxidants nitrate, manganese, iron, and sulfate in the top 30 cm of cores collected along a transect from Hawaii to Alaska. The data show large increases in porewater concentrations of vanadium, manganese, cobalt, nickel, copper, and arsenic within the top cm of the sediment, consistent with the release of these elements from remineralized organic matter. The sediments are a sink for sulfate, uranium, and molybdenum, even though conditions within the sampled top 30 cm remain aerobic. Porewater chromium concentrations generally increase with depth due to release from sediment particles. Extrapolated to the global aerial extent of pelagic clay sediment, the benthic fluxes in mol yr−1 are Ba 3.9 ± 3.6 × 109, Mn 3.4 ± 3.5 × 108, Co 2.6 ± 1.3 × 107, Ni 9.6 ± 8.6 × 108, Cu 4.6 ± 2.4 × 109, Cr 1.7 ± 1.1 × 108, As 6.1 ± 7.0 × 108, V 6.0 ± 2.5 × 109. With the exception of vanadium, calculated fluxes across the sediment–water interface are consistent with the variability in bottom-water concentrations and ocean residence time of the studied elements.

Berelson William M.

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