Keri Opalk
YOU?
Author Swipe
View article: Diel study reveals increased nighttime bacterial activity and its connection to organic compounds in the ocean
Diel study reveals increased nighttime bacterial activity and its connection to organic compounds in the ocean Open
The linkages between dissolved organic matter (DOM) dynamics and bacterial activity (BAct) are key to regulating carbon fluxes in marine food webs. While transcriptional activities have shown diel patterns, the connections between BAct and…
View article: Senescence-driven solubilization of biomass is the main source of kelp-derived dissolved organic carbon to the coastal ocean
Senescence-driven solubilization of biomass is the main source of kelp-derived dissolved organic carbon to the coastal ocean Open
Kelp forests form some of the most productive areas on earth and are proposed to sequester carbon in the ocean, largely in the form of released dissolved organic carbon (DOC). Here we investigate the role of environmental, seasonal and age…
View article: Pre‐existing phytoplankton biomass concentrations shape coastal plankton response to fire‐generated ash leachate
Pre‐existing phytoplankton biomass concentrations shape coastal plankton response to fire‐generated ash leachate Open
Climate‐driven warming is projected to intensify wildfires, increasing their frequency and severity globally. Wildfires are an increasingly significant source of atmospheric deposition, delivering nutrients, organic matter, and trace metal…
View article: Seasonal and developmental stage changes in exudate carbohydrate content shape the kelp microbiome
Seasonal and developmental stage changes in exudate carbohydrate content shape the kelp microbiome Open
Photoautotrophs release a large amount of their fixed carbon as exudates, which shapes their immediate environment, including the composition of their microbiome. Here we evaluated the microbiome and exudate composition of Macrocystis pyri…
View article: Photooxidation removes biologically recalcitrant dissolved organic carbon released by the macroalga <i>Sargassum natans</i>
Photooxidation removes biologically recalcitrant dissolved organic carbon released by the macroalga <i>Sargassum natans</i> Open
Macroalgae are important primary producers in the coastal ocean, and they release a large fraction of their net primary production as dissolved organic carbon (DOC). It is assumed that much of this DOC is recalcitrant and results in the se…
View article: Senescence-driven solubilization of kelp biomass is a potentially large source of dissolved organic carbon to the coastal ocean
Senescence-driven solubilization of kelp biomass is a potentially large source of dissolved organic carbon to the coastal ocean Open
Kelp forests form some of the most productive areas on earth and are proposed to sequester carbon in the ocean, largely in the form of released dissolved organic carbon (DOC). Here we investigate the role of environmental, seasonal and age…
View article: Senescence driven solubilization of biomass is the main source of kelp-derived dissolved organic carbon to the coastal ocean
Senescence driven solubilization of biomass is the main source of kelp-derived dissolved organic carbon to the coastal ocean Open
Kelp forests form some of the most productive areas on earth and are proposed to sequester carbon in the ocean, largely in the form of released dissolved organic carbon (DOC). Here we investigate the role of environmental, seasonal and age…
View article: Oxidation state of bioavailable dissolved organic matter influences bacterioplankton respiration and growth efficiency
Oxidation state of bioavailable dissolved organic matter influences bacterioplankton respiration and growth efficiency Open
Oxygen consumption by oceanic microbes can predict respiration (CO2 production) but requires an assumed respiratory quotient (RQ; ΔO2/ΔCO2). Measured apparent RQs (ARQs) can be impacted by various processes, including nitrification and cha…
View article: Seasonal and developmental stage changes in mucilage carbohydrate content shape the kelp microbiome
Seasonal and developmental stage changes in mucilage carbohydrate content shape the kelp microbiome Open
A large amount of a photoautotroph’s fixed carbon is released as dissolved organic matter, from both exudation and solubilized detritus. This dissolved material contributes to a surface mucilage layer that shapes their immediate environmen…
View article: Suboxic DOM is bioavailable to surface prokaryotes in a simulated overturn of an oxygen minimum zone, Devil’s Hole, Bermuda
Suboxic DOM is bioavailable to surface prokaryotes in a simulated overturn of an oxygen minimum zone, Devil’s Hole, Bermuda Open
Oxygen minimum zones (OMZs) are expanding due to increased sea surface temperatures, subsequent increased oxygen demand through respiration, reduced oxygen solubility, and thermal stratification driven in part by anthropogenic climate chan…
View article: Oxidation state of bioavailable dissolved organic matter influences bacterioplankton respiration and growth efficiency
Oxidation state of bioavailable dissolved organic matter influences bacterioplankton respiration and growth efficiency Open
Heterotrophic bacterioplankton use oxygen and dissolved organic matter (DOM) to acquire energy, carbon and nutrients necessary for growth; however, the impacts of the chemical composition of DOM on the ratio of oxygen uptake to carbon resp…
View article: Determination of dissolved organic carbon and total dissolved nitrogen in seawater using High Temperature Combustion Analysis
Determination of dissolved organic carbon and total dissolved nitrogen in seawater using High Temperature Combustion Analysis Open
This document describes best practices for analysis of dissolved organic matter (dissolved organic carbon and total dissolved nitrogen) in seawater samples. Included are SOPs for sample collection and storage, details for laboratory analys…
View article: Linkages Among Dissolved Organic Matter Export, Dissolved Metabolites, and Associated Microbial Community Structure Response in the Northwestern Sargasso Sea on a Seasonal Scale
Linkages Among Dissolved Organic Matter Export, Dissolved Metabolites, and Associated Microbial Community Structure Response in the Northwestern Sargasso Sea on a Seasonal Scale Open
Deep convective mixing of dissolved and suspended organic matter from the surface to depth can represent an important export pathway of the biological carbon pump. The seasonally oligotrophic Sargasso Sea experiences annual winter convecti…
View article: Bacterioplankton response to physical stratification following deep convection
Bacterioplankton response to physical stratification following deep convection Open
Dissolved organic carbon (DOC) produced by primary production in the sunlit ocean can be physically transported to the mesopelagic zone. The majority of DOC exported to this zone is remineralized by heterotrophic microbes over a range of t…
View article: Organic Matter Composition at Ocean Station Papa Affects Its Bioavailability, Bacterioplankton Growth Efficiency and the Responding Taxa
Organic Matter Composition at Ocean Station Papa Affects Its Bioavailability, Bacterioplankton Growth Efficiency and the Responding Taxa Open
The bioavailability of organic matter (OM) to marine heterotrophic bacterioplankton is determined by both the chemical composition of OM and the microbial community composition. In the current study, changes in OM bioavailability were iden…
View article: Stable Isotope Probing Identifies Bacterioplankton Lineages Capable of Utilizing Dissolved Organic Matter Across a Range of Bioavailability
Stable Isotope Probing Identifies Bacterioplankton Lineages Capable of Utilizing Dissolved Organic Matter Across a Range of Bioavailability Open
Bacterioplankton consume about half of the dissolved organic matter (DOM) produced by phytoplankton. DOM released from phytoplankton consists of a myriad of compounds that span a range of biological reactivity from labile to recalcitrant. …
View article: Deep sea dissolved organic nitrogen and phosphorus (DON and DOP) at Station ALOHA in the North Pacific Subtropical Gyre
Deep sea dissolved organic nitrogen and phosphorus (DON and DOP) at Station ALOHA in the North Pacific Subtropical Gyre Open
Data on organic and inorganic nutrients in unfiltered seawater that was sampled at and around Station ALOHA, north of Oahu, Hawaii, in the North Pacific Subtropical Gyre. Seawater was collected into HDPE or polypropylene bottles and immedi…
View article: Deep sea dissolved organic nitrogen and phosphorus (DON and DOP) at Station ALOHA in the North Pacific Subtropical Gyre
Deep sea dissolved organic nitrogen and phosphorus (DON and DOP) at Station ALOHA in the North Pacific Subtropical Gyre Open
Data on organic and inorganic nutrients in unfiltered seawater that was sampled at and around Station ALOHA, north of Oahu, Hawaii, in the North Pacific Subtropical Gyre. Seawater was collected into HDPE or polypropylene bottles and immedi…
View article: Different carboxyl‐rich alicyclic molecules proxy compounds select distinct bacterioplankton for oxidation of dissolved organic matter in the mesopelagic Sargasso Sea
Different carboxyl‐rich alicyclic molecules proxy compounds select distinct bacterioplankton for oxidation of dissolved organic matter in the mesopelagic Sargasso Sea Open
Marine dissolved organic matter (DOM) varies in its recalcitrance to rapid microbial degradation. DOM of varying recalcitrance can be exported from the ocean surface to depth by subduction or convective mixing and oxidized over months to d…
View article: Improved ultraviolet photo‐oxidation system yields estimates for deep‐sea dissolved organic nitrogen and phosphorus
Improved ultraviolet photo‐oxidation system yields estimates for deep‐sea dissolved organic nitrogen and phosphorus Open
Photolysis of dissolved organic matter using high‐intensity, ultraviolet (UV) light has been utilized since the 1960s as a method for the oxidation and subsequent quantification of dissolved organic nitrogen and phosphorus (DON and DOP) in…