Mariana Bernardi Bif

Monterey Bay Aquarium Research Institute

Sensors that use ultraviolet (UV) light absorption to measure nitrate in seawater at in situ temperatures require a correction to the calibration coefficients if the calibration and sample temperatures are not identical. This is mostly due to the bromide molecule, which absorbs more UV light as temperature increases. The current correction applied...

Here we used data from six BGC-floats deployed in the southeast Pacific and southwest Atlantic Oceans, within the Southern Ocean's Subtropical Zone, to assess the seasonality of particulate organic carbon production from phytoplankton (POC phyto) and estimate POC transfer efficiencies at 100 m below the euphotic zone (T_100). While small particles...

Marine diazotrophs convert dinitrogen (N2) gas into bioavailable nitrogen (N), supporting life in the global ocean. In 2012, the first version of the global oceanic diazotroph database (version 1) was published. Here, we present an updated version of the database (version 2), significantly increasing the number of in situ diazotrophic measurements...

Measurements of dissolved organic carbon (DOC), nitrogen (DON), and phosphorus (DOP) concentrations are used to characterize the dissolved organic matter (DOM) pool and are important components of biogeochemical cycling in the coastal ocean. Here, we present the first edition of a global database (CoastDOM v1; available at 10.1594/PANGAEA.964012, L...

The impact of marine heatwaves (MHWs) on ecosystem functions and services remains poorly constrained due in part to the limited availability of time-resolved datasets integrating physical, chemical and biological parameters at relevant operating scales. Here we paired over a decade of autonomous Biogeochemical (BGC)-Argo profiling float data with w...

The measurements of dissolved organic carbon (DOC), nitrogen (DON), and phosphorus (DOP) are used to characterize the dissolved organic matter (DOM) pool and are important components of biogeochemical cycling in the coastal ocean. Here, we present the first edition of a global database (CoastDOM v1; available at https://figshare.com/s/512289eb43c4f...

The adopt-a-float program is a link between GO-BGC, SOCCOM, Marine Scientists and elementary to K-12 students. It brings ocean science and technology into the classroom by allowing students to name a float, then follow its trajectory in the ocean. www.go-bgc.org/outreach/adopt-a-float

Measurements of pH and nitrate from the Southern Ocean Carbon and Climate Observations and Modeling array of profiling floats were used to assess the ratios of dissolved inorganic carbon (DIC) and nitrate (NO3) uptake during the spring to summer bloom period throughout the Southern Ocean. Two hundred and forty‐three bloom periods were observed by 1...

Here we use data from three meridional survey cruises that took place in in the southeast Pacific Ocean to investigate controls on surface distributions of dissolved organic carbon and nitrogen (DOC and DON, respectively). While DOC and DON production occur simultaneously in the euphotic layer of the gyre margins, budgets that account for horizonta...

We leverage observations from chemical and bio‐optical sensors mounted on a biogeochemical profiling float in the Northeast Pacific Ocean to quantify the cycling and export potential of distinct biogenic carbon pools, including particulate inorganic carbon (PIC), particulate organic carbon (POC), and dissolved organic carbon (DOC). Year‐round obser...

The biological transformation of dissolved inorganic carbon to organic carbon during photosynthesis in the ocean, marine primary production, is a fundamental driver of biogeochemical cycling, ocean health and Earth’s climate system. The organic matter created supports oceanic food webs, including fisheries, and is an essential control on atmospheri...

Compilation of dissolved organic matter (DOM) data obtained from global ocean observations from 1994 to 2020 This compilation consists of measurements of dissolved organic matter (DOM) and other chemical and hydrographic parameters obtained during the global ocean observations from 1994-01-01 to 2019-12-31. Measurements of dissolved organic matter...

As atmospheric CO2 rises, the ocean warms, winds shift, and ice melts. Numerical models suggest that large changes in ocean chemistry and biology will result. Traditionally, the biogeochemical (BGC) measurements used to identify such changes have been made from research vessels, particularly for the ocean interior, which is not accessible by satell...

• DOC and DON are produced at greatest rates in regions such as equatorial and coastal zones and upwelling systems as a result of enhanced primary production. • While DOC surface distribution behaves more conservatively, DON does not. This implies that physical and biological processes must control their distribution differently. • Subtropical gyre...

Between 2013 and 2016, a series of warm events induced by ocean atmosphere oscillations negatively impacted productivity in the northeast Pacific Ocean. For two consecutive winters (2013–2014 and 2014–2015), suppressed wind stress and warm near‐surface ocean temperature anomalies restricted vertical mixing between the surface and underlying nutrien...

The cycling of bioactive elements on Earth and their allocation into major reservoirs is driven through their biogeochemical transformations. Carbon, for example, is biologically transformed by primary producers that convert CO2 to organic carbon during photosynthesis, which is then respired back to the gaseous form by heterotrophs. The cycling of...

From seasonal cruises in the NE Pacific Ocean during 2017, we (1) determined dissolved organic carbon concentrations; (2) calculated net community production (NCP) from nitrate drawdown; and (3) established relationships between NCP and seasonal dissolved organic carbon (DOC) accumulation in the upper 75 m. The fraction of NCP that accumulated as D...

The spatial distribution and species identification of Trichodesmium was assessed during two fall cruises along the Southwest Atlantic Ocean shelf break. Organisms from the microplankton >50 μm were collected using a vertical plankton net for quantification and identification of the microplanktonic community associated with the genus. Additional su...

To understand controls on the production and remineralization of recalcitrant dissolved organic carbon (DOC) produced in association with positive net community production (NCP), we simulated upwelling systems of different intensities by combining and incubating whole seawater collected from different depths in the Florida Strait (27°N, ∼79°W). The...

• Measurements of dissolved organic carbon (DOC) in the ocean still require ships, and the chemical analysis is very time-consuming • DOC concentrations can be estimated from net community production (NCP) if a constant fraction of NCP seasonally accumulates as DOC, called Net Dissolved Production Ratio (NDPr) • NCP can be calculated for a region u...

The genus Trichodesmium is a nitrogen-fixer commonly found through tropical and subtropical ocean basins, however, only a few reports address their distribution in the South Atlantic Ocean. Our studies used observational data (physical, chemical and biological) to understand the distribution and ecology of Trichodesmium associated with fronts produ...

Introduction and methodology This study investigated the role of microbial communities in net dissolved organic matter production and associated inorganic nutrient uptake, and subsequent catabolism of DOM by heterotrophic bacteria. Using natural water and microbial populations, we simulated upwelling systems of different intensities by combining se...

This study investigates organic matter–microbe interactions by focusing on the production and fate of organic carbon, as well as the environmental factors influencing its bioreactivity.

Members of the genus Trichodesmium are commonly found in nutrient-limited tropical and subtropical ocean basins due to their capacity to fix atmospheric nitrogen (N2). However, N2 fixation requires supplementary iron and phosphorus, which can potentially become limiting nutrients for the growth of Trichodesmium. In order to understand the ecology a...

The genus Trichodesmium occurs in tropical and subtropical oceans through the world and contributes to the nitrogen and carbon cycle. As a diazotrophic organism, it establishes populations in oligotrophic oceans, where other planktonic organisms cannot develop because of dissolved nitrogen limitation. In spite of their large biomass, they are poorl...