Kenneth W. Bruland

Kenneth W. Bruland
University of California, Santa Cruz | UCSC · Department of Ocean Sciences,

PhD, SIO/UCSD

About

216
Publications
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Publications

Publications (216)
Article
Full-text available
Diatom primary productivity is tightly coupled with carbon export through the ballasted nature of the silica-based cell wall, linking the oceanic silicon and carbon cycles. However, despite low productivity, iron (Fe)-limited regimes are considered ‘hot spots’ of diatom silica burial with enhanced carbon export efficiency, raising questions about t...
Article
Full-text available
Nickel (Ni) is a bio-essential element required for the growth of phytoplankton. It is the least studied bio-essential element, mainly because surface ocean Ni concentrations are never fully depleted and Ni is not generally considered to be a limiting factor. However, stimulation of growth after Ni addition has been observed in past experiments whe...
Article
Trace element (TE) fluxes and their residence times (Fe, Mn, Cu, Pb, Cd, and V) within the surface ocean were determined along the GEOTRACES East Pacific Zonal Transect (GP16/EPZT) and found to reflect the diverse physical and geochemical conditions encountered across the track. The TE flux from atmospheric deposition, vertical mixing, and upwellin...
Article
Full-text available
Dissolved zinc (Zn) has a nutrient-type distribution in the ocean that more closely resembles the distribution of silicate (Si) than phosphate (PO4). However, Zn is a trace-nutrient and mostly present in the organic fraction of phytoplankton rather than the siliceous frustule. It has been suggested the coupling of Zn and Si is caused by the strong...
Article
Full-text available
Diatoms are prominent eukaryotic phytoplankton despite being limited by the micronutrient iron in vast expanses of the ocean. As iron inputs are often sporadic, diatoms have evolved mechanisms such as the ability to store iron that enable them to bloom when iron is resupplied and then persist when low iron levels are reinstated. Two iron storage me...
Article
Coastal upwelling of nutrients and metals along eastern boundary currents fuels some of the most biologically productive marine ecosystems. Although iron is a main driver of productivity in many of these regions, iron cycling and acquisition by microbes remain poorly constrained, in part due to the unknown composition of organic ligands that keep b...
Article
Full-text available
The California Current System is a productive eastern boundary region off the coasts of Washington, Oregon, and California. There is strong seasonality to the region, with high levels of rainfall and river input to the coastal ocean during the winter season, and coastal and Ekman upwelling during the spring and summer. Iron (Fe) input to the coasta...
Article
Cadmium (Cd) is not generally considered a nutrient element, but behaves like a nutrient in the oceans and might play an important role in ocean biology after all. The relationship between Cd and the nutrient phosphate (PO4) has been studied for over 40 yrs, but the debate on the driving mechanism and reason behind the ‘kink’, a change in the steep...
Article
Full-text available
The GEOTRACES Intermediate Data Product 2017 (IDP2017) is the second publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2016. The IDP2017 includes data from the Atlantic, Pacific, Arctic, Southern and Indian oceans, with about twice the data volume of the pre...
Article
The GEOTRACES Intermediate Data Product 2017 (IDP2017) is the second publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2016. The IDP2017 includes data from the Atlantic, Pacific, Arctic, Southern and Indian oceans, with about twice the data volume of the pre...
Preprint
Full-text available
Frequent blooms of phytoplankton occur in coastal upwelling zones creating hotspots of biological productivity in the ocean. As cold, nutrient-rich water is brought up to sunlit layers from depth, phytoplankton are also transported upwards to seed surface blooms that are often dominated by diatoms. The physiological response of phytoplankton to thi...
Article
Seawater samples were collected at the Vertex IV site at 28°N, 155°W in the central North Pacific Ocean. The very old deep waters show low concentrations of dissolved Ce, and the lowest values worldwide of dissolved Ce relative to the other REE, as defined by either the Ce/Nd ratio or the Ce anomaly Ce/Ce*. The very old deep waters in the central N...
Article
Full-text available
Precise and accurate quantification of Ag and platinum group elements in marine, estuarine and riverine waters is challenging due to the complex matrices and ultra-low concentrations in the pmol kg− 1 and fmol kg− 1 range. A methodological approach has been developed for the analysis of Ag and Pt in seawater based on the extraction of their anionic...
Article
Full-text available
Changes in iron (Fe) bioavailability influence diatom physiology and community composition, and thus have a profound impact on primary productivity and ecosystem dynamics. Iron limitation of diatom growth rates has been demonstrated in both oceanic and coastal waters of the Northeast Pacific Ocean and is predicted to become more pervasive in future...
Article
Full-text available
Recent work has begun to elucidate the biogeochemical cycling of scandium (Sc) in the open ocean, but so far no surface distribution data has been reported of dissolved Sc, and no basin-scale surface distributions have been reported of yttrium (Y) or lanthanum (La). This work presents basin-wide surface Sc, Y and La data in a section across the Nor...
Article
Full-text available
Organic ligands form strong complexes with many trace elements in seawater. Various metals can compete for the same ligand chelation sites, and the final speciation of bound metals is determined by relative binding affinities, concentrations of binding sites, uncomplexed metal concentrations, and association/dissociation kinetics. Different ligands...
Article
Full-text available
Little is known about the distribution of scandium (Sc) in the open ocean. Since the 1970s there has been only one published depth profile of dissolved Sc. The work presented here reports depth profiles of dissolved Sc from GEOTRACES cruises in the North Atlantic, North Pacific and South Pacific. This work also compares the reactivity of Sc with it...
Article
We evaluated both the spatial distribution of gadolinium (Gd) and other rare earth elements (REE) in surface waters collected in a transect of San Francisco Bay (SFB), and their temporal variations within the Bay over two decades. The REE were pre-concentrated using the NOBIAS PA-1® resin, prior to analysis by high resolution inductively coupled pl...
Data
This R script contains the functions used to assess whether two datasets at the same station are statistically different or not as described in 'Intercomparison of dissolved trace elements at the Bermuda Atlantic Time Series station' (http://dx.doi.org/10.1016/j.marchem.2015.06.014)
Data
This R script is an example of how one could use the functions in geotraces_dataprocessing_v6.1_.R to assess the comparability between to data-sets at the same station.
Article
Full-text available
The GEOTRACES Intermediate Data Product 2014 (IDP2014) is the first publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2013. It consists of two parts: (1) a compilation of digital data for more than 200 trace elements and isotopes (TEIs) as well as classical...
Article
The resin NOBIAS-chelate PA-1® was used to develop an off-line pre-concentration and extraction method for rare earth elements (REEs) in seawater prior to quantification using magnetic sector, high resolution, inductively coupled plasma mass spectrometry (HR ICP-MS). The method employed an off-line manifold that is inexpensive, easy to set-up, and...
Article
Organic dissolved iron (dFe)-binding ligands were measured by competitive ligand exchange-adsorptive cathodic stripping voltammetry (CLE-ACSV) at multiple analytical windows (side reaction coefficient of salicylaldoxime, alpha(Fe(SA)2) = 30, 60, and 100) in surface and benthic boundary layer (BBL) samples along the central California coast during s...
Chapter
This chapter presents a general overview of the major controls of trace metals in seawater, developed from the extensive research on trace metals over the last few decades. The reader should be given a first-order understanding and insight into trace metal biogeochemistry in the oceans, rather than presented with a comprehensive review of the distr...
Chapter
p>This chapter presents a general overview of the major controls of trace metals in seawater, developed from the extensive research on trace metals over the last few decades. The reader should be given a first-order understanding and insight into trace metal biogeochemistry in the oceans, rather than presented with a comprehensive review of the dis...
Article
Distributions of iron and nitrate in the central California Current System upwelling regime (cCCS) from 34 to 41°N were determined during cruises in May 2010 and August 2011. High spatial and temporal resolution data for dissolved Fe and NO3- (nitrate+nitrite) in the cCCS from this study greatly expands upon previous studies that were narrower in s...
Article
Coastal upwelling in the central California Current System (cCCS) delivers macro and micronutrients to the surface ocean that fuel biological productivity. Variations in upwelling strength and continental shelf width affect trace metal sources seasonally. The purpose of this study was to investigate various sources and distributions for a suite of...
Article
The transition zone (TZ) of the central California Current upwelling system (cCCS) is the boundary between the cold, saline, coastally upwelled water and the warm, less saline, oligotrophic waters of the offshore California Current (CC). The TZ is a broad region that regularly exhibits chlorophyll concentrations of 1-2 μg L-1 throughout the spring,...
Article
A system for the rapid and noncontaminating sampling of trace elements with volumes of up to 36 L per depth and including the dissolved and particulate phases has been developed for ocean sections that are a crucial part of programs such as International GEOTRACES. The system uses commercially available components, including an aluminum Seabird Car...
Article
Full-text available
A diel biogeochemical study was performed to assess the influence that periods of elevated biological activity have on the biogeochemical cycling of macronutrients and redox-sensitive elements in a natural estuarine environment. High-resolution data (15 min sampling) illustrates periodic extreme variations in dissolved oxygen (DO) in the shallow wa...
Article
In order to establish the status of metal contamination in surface waters in the coastal ocean off Los Angeles, California, we determined their dissolved and particulate pools and compared them with levels reported in the 1970s prior the implementation of the Clean Water Act. These measurements revealed a significant reduction in particulate toxic...
Article
In the northern Gulf of Alaska, mesoscale, anticyclonic eddies have been implicated as a mechanism of the cross-shelf exchange of iron (Fe)-replete coastal waters with Fe-deplete subarctic Alaskan gyre waters. Based on existing hydrography and macronutrient distributions, a Sitka eddy sampled during August 2007 is divided into a surface eddy core,...
Article
A method was developed using the chelating resin Nobias-chelate PA1 in an off-line pre-concentration manifold with magnetic sector inductively coupled plasma mass spectrometry (ICP-MS) detection for analysis of Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb. This multi-element method allows for the simultaneous extraction of eight samples in a closed column ma...
Article
Mesoscale anticyclonic eddies in the Gulf of Alaska are an important mechanism for cross-shelf exchange of high iron, low nitrate coastal waters and low iron, high nitrate offshore waters. A Kenai eddy was sampled in September 2007, 8 months after formation. The subsurface eddy core layer contained reactive iron concentrations more than eight times...
Article
Trace elements in seawater can be limiting factors of biological productivity, tracers of ocean circulation and biogeochemical processes, and proxies for paleoceanography. The global status of trace elements and their isotopes (TEIs) in the ocean is being explored this decade through an international study of the global marine biogeochemical cycles...
Article
Trace metals in the ocean act as both essential micro-nutrients and as toxins. There are relatively few multi-element studies of dissolved trace metals in the ocean, and none from the Gulf of Aqaba, Red Sea. This semi-enclosed basin surrounded by desert is a natural laboratory for studying the impact of atmospheric dry deposition of trace metals on...
Data
Full-text available
A majority of eukaryotic phytoplankton species require an exogenous source of vitamin B12 for growth and recent field studies in some coastal and polar regions indicate that the addition of vitamin B12 alone, or with another limiting nutrient can influence the accumulation of phytoplankton biomass. We quantified the concentrations and uptake rates...
Article
Coastal waters in the northern Gulf of Alaska (GoA) are considered Fe-rich and nitrate-poor, in contrast to the Fe-poor, high-nitrate, low chlorophyll (HNLC) waters of the central GoA. Mixing between these two regimes can lead to enhanced primary productivity. Mesoscale anticyclonic eddies are an important mechanism for cross-shelf exchange of coas...
Article
Full-text available
Near-surface waters ranging from the Pacific subarctic (58°N) to the Southern Ocean (66°S) contain the neurotoxin domoic acid (DA), associated with the diatom Pseudo-nitzschia. Of the 35 stations sampled, including ones from historic iron fertilization experiments (SOFeX, IronEx II), we found Pseudo-nitzschia at 34 stations and DA measurable at 14...
Article
The coastal northern Gulf of Alaska receives significant fluvial inputs from the numerous glaciers and rivers that border the region. The distribution of dissolved (soluble and total) and particulate aluminum (leachable and total) was examined in coastal surface water transects and vertical profile samples from shelf stations in the northern Gulf o...
Article
Full-text available
1] Large rivers represent gateways for the transport of terrigenous and anthropogenic material to the coastal ocean. Here we document a ∼700 km 2 recirculation or bulge associ-ated with the Columbia River plume that retains recently dis-charged river water sufficiently to create a regional bioreactor. Fueled by a fluvial nitrate source, this featur...
Article
Coastal waters in the northern Gulf of Alaska (GoA) are considered iron-rich and nitrate-poor, in contrast to the iron-poor, high-nitrate, low chlorophyll (HNLC) waters of the central GoA. The degree of mixing between these two regimes, enhanced by mesoscale eddies, is essential to the high productivity observed in the region. As part of a study on...
Article
This study examines the distribution of leachable particulate iron (Fe) in the Columbia River, estuary, and near-field plume. Surface samples were collected during late spring and summer of 2004–2006 as part of four River Influence on Shelf Ecosystems (RISE) cruises. Tidal amplitude and river flow are the primary factors influencing the estuary lea...
Article
Surface transects and vertical profiles of total and leachable particulate Fe, Mn, Al and P, along with dissolved and soluble Fe were obtained during August 2003 in the southeastern Bering Sea. High concentrations of leachable particulate Fe were observed in the bottom waters over the Bering Sea shelf with an unusually high percentage of the suspen...
Article
River Influences on Shelf Ecosystems (RISE) is the first comprehensive interdisciplinary study of the rates and dynamics governing the mixing of river and coastal waters in an eastern boundary current system, as well as the effects of the resultant plume on phytoplankton standing stocks, growth and grazing rates, and community structure. The RISE S...
Article
Full-text available
1] River Influences on Shelf Ecosystems (RISE) is the first comprehensive interdisciplinary study of the rates and dynamics governing the mixing of river and coastal waters in an eastern boundary current system, as well as the effects of the resultant plume on phytoplankton standing stocks, growth and grazing rates, and community structure. The RIS...
Article
1] River Influences on Shelf Ecosystems (RISE) is the first comprehensive interdisciplinary study of the rates and dynamics governing the mixing of river and coastal waters in an eastern boundary current system, as well as the effects of the resultant plume on phytoplankton standing stocks, growth and grazing rates, and community structure. The RIS...
Article
A lower trophic level NPZD ecosystem model with explicit iron limitation on nutrient uptake is coupled to a three-dimensional coastal ocean circulation model to investigate the regional ecosystem dynamics of the northwestern coastal Gulf of Alaska (CGOA). Iron limitation is included in the NPZD model by adding governing equations for two micro-nutr...
Article
Mesoscale eddies in the Gulf of Alaska are thought to contribute to the shelf-slope exchange of nutrients and plankton, enhancing biological production. We report on a study of two anticyclonic mesoscale eddies in this region observed through in situ sampling during August and September 2007. Both eddies exhibited in their cores $\theta$-S profiles...
Article
The distribution of dissolved (soluble and total) and particulate (leachable and total) aluminum was examined in the Columbia River and estuary, in near-field and far-field river plumes, and in adjacent coastal waters of Washington and Oregon during the River Influence on Shelf Ecosystems (RISE) cruise of May/June 2006. Dissolved and particulate al...
Article
Coastal waters in the northern Gulf of Alaska (GoA) are considered iron-rich and nitrate-poor, in contrast to the iron-poor, high-nitrate, low chlorophyll (HNLC) waters of the central GoA. The degree of mixing between these two regimes, enhanced by mesoscale eddies, is essential to the high productivity observed in the region. As part of a study on...
Article
There has been a growing interest in the cause and impact of hypoxic regions known as "dead zones" that have increasingly appeared along the west coast of the United States and have caused widespread destruction to the crab and fishing industry in this upwelling region. Here, we present results that demonstrate that the hypoxic conditions in the wa...
Article
Factors influencing concentrations of nitrate, silicic acid, dissolved Fe, and dissolved Mn in the near-field Columbia River plume were examined during late spring and summer from 2004 to 2006 as part of the River Influences on Shelf Ecosystems program. Under upwelling-active phases, cold, high-nitrate coastal seawater was entrained in the plume, a...
Article
Full-text available
In order to determine the total concentration of bioavailable trace metals in seawater, measurement of both the dissolved and labile particulate fractions is necessary. Comparison of labile particulate metal concentrations from various researchers is limited because of differing definitions of the fraction that is potentially available to phytoplan...
Article
The distributions of particulate elements (Al, P, Mn, Fe, Co, Cu, Zn, Cd, and Pb), dissolved trace metals (Mn, Fe, Co, Cu, Zn, and Cd), and dissolved nutrients (nitrate, phosphate, and silicic acid) were investigated in the Gulf of the Farallones, a region of high productivity that is driven by the dynamic mixing of the San Francisco Bay plume, upw...
Article
An improved, highly sensitive, flow-injection analysis method for the determination of dissolved aluminum in seawater, based on the work of Resing and Measures (1994), is presented. The most significant modification to this earlier work is the use of in-line preconcentration of seawater onto a commercially available resin, eliminating the resin-syn...
Article
Full-text available
The physicochemical speciation of dissolved iron (Fe) across natural dissolved Fe gradients in the oceanic and shelf domains of the southeastern Bering Sea was examined in surface and subsurface samples using competitive ligand exchange-adsorptive cathodic stripping voltammetry with the added ligand salicylaldoxime. Two ligand classes were measured...
Article
A method employing dual competitive ligand exchange followed by solid phase extraction (CLE-SPE) for characterizing the complexation of inorganic Hg(II) in natural waters is described. This method employs parallel use of two competing ligands: diethyldithiolcarbamate (DEDC), which forms hydrophobic complexes with Hg(II), and thiosalicylic acid (TSA...
Article
Following basin-wide contamination from industrial emissions and urban development, total dissolved copper concentrations in some regions of San Francisco Bay have exceeded national and state guidelines for water quality. In the face of dramatic improvements in wastewater treatment and point source control, persisting elevated dissolved copper conc...
Article
Surface transects and vertical profiles of macronutrients, dissolved iron (D-Fe), and dissolved manganese (D-Mn) were investigated during August 2003 in the southeastern Bering Sea. We observed iron-limited, HNLC surface waters in the deep basin of the Bering Sea (15-20 μmol/kg nitrate, ∼0.07 nmol/kg D-Fe, and ≤1.0 nmol/kg D-Mn); nitrate-limited, i...
Article
Full-text available
In nearly a dozen open-ocean fertilization experiments conducted by more than 100 researchers from nearly 20 countries, adding iron at the sea surface has led to distinct increases in photosynthesis rates and biomass. These experiments confirmed the hypothesis proposed by the late John Martin that dissolved iron concentration is a key variable that...
Article
Dissolved iron (Fe) speciation in the Columbia River plume, the San Francisco Bay plume, and the Columbia River estuary was investigated using competitive ligand exchange-adsorptive cathodic stripping voltammetry (CLE-ACSV) with the added ligand salicylaldoxime. A stronger L₁-type Fe-binding ligand class was measured in all surface samples, and in...
Article
A vertical mixing event was simulated in shipboard incubation experiments on the mid-continental shelf of the eastern Bering Sea to investigate Fe and Zn cycling between the soluble (< 0.03 μm or 200 kDa), colloidal (0.03–0.2 μm), and particulate (0.2–10 μm, > 10 μm) size-fractions. The particulate Fe and Zn were further separated into chemically l...
Article
The NSF-sponsored Coastal Ocean Processes Wind Events and Shelf Transport (WEST) experiment investigates the interplay between wind-driven transport and shelf productivity; while eastern boundary shelves are characterized by high productivity due to upward fluxes of nutrients into the euphotic zone, wind forcing also represents negative physical an...
Article
Full-text available
The spring onset of persistent upwelling-favorable winds was later than usual in the northern California Current system in 2005, resulting in delayed provision of inorganic nutrients to the upper waters of the coastal ocean. This study uses water column measurements to illustrate the evolution of temperature, salinity, nitrate and chlorophyll a pri...
Article
The spatial distributions of dissolved manganese and nutrients were examined in the Columbia River plume off Oregon and Washington during the summer of 2004 and 2005 as part of the River Influence on Shelf Ecosystems (RISE) program. Factors influencing the hydrochemical characteristics of the freshly formed and aged Columbia River plume were invest...
Article
This presentation is a review of the chemistries of redox sensitive elements within suboxic regions of extreme oxygen minimum zones. Suboxic regions are defined as extreme oxygen minimum zones with dissolved oxygen < 10 μmol kg-1 (and likely <5 μmol kg-1), and with clear evidence of nitrate reduction, but not sulfate reduction. These are regions wi...
Article
A sensitive flow injection method for determining iron in seawater developed by Measures et al. (1995) has been substantially modified to allow the direct preconcentration of dissolved iron in acidified seawater samples (pH 1.7) onto a nitrilotriacetic acid (NTA) chelating resin. This removes the need to adjust the pH and buffer samples before the...
Article
The sensitive, laboratory- and ship-based, flow-injection (FI) method for the determination of dissolved man- ganese in seawater developed by Resing and Mottl (Anal. Chem. 1992;64:2682-2687) has been significantly modi- fied and improved by incorporating five significant changes. The three major changes are the use of a commer- cially available imi...
Article
Phytoplankton community structure in the eastern Equatorial Pacific (EEP) and the Peru upwelling system was determined using ChemTax analysis of pigment data. Photosynthetic efficiencies $(F_{v}\colon F_{m})$ concentrations of macronutrients, iron (Fe), and the redox proteins flavodoxin (Flv) and ferredoxin (Fd) were used to assess the physiologica...