Raissa Philibert

Ecofish Research Ltd · EIS

Net primary production (NPP) fueled by nitrate is often equated with carbon export, providing a metric for CO 2 removal to the deep ocean. This "new production paradigm" assumes that nitrification, the oxidation of regenerated ammonium to nitrate, is negligible in the sunlit upper ocean. While surface layer nitrification has been measured in other...

In this study, we have seen a variety of physical (temperature, salinity, mixed layer, depth and the resulting water column structure) and chemical (macronutrients) properties influence phytoplankton abundance and shape community structure. In addition, we showed how micronutrients are a vital, additional parameter which can account for variability...

This poster explains the region specific responses (community structure and photophysiology) of phytoplankton communities found in two very different water masses within the Atlantic Southern Ocean. Understanding the response of phytoplankton communities to specific environmental drivers in different Southern Ocean water masses is critical to impro...

Availability of dissolved iron and light are both regulating factors for primary productivity in high (macro)nutrient, low chlorophyll regions of the Southern Ocean. Here, using on-board iron/light incubation experiments conducted in 2015 in the Atlantic sector of the Southern Ocean, we show that irradiance limited significant phytoplankton growth...

The impact of light and nutrients (such as silicate and iron) availability on nitrogen uptake and primary production vary seasonally and regionally in the Southern Ocean. The seasonal cycle of nitrogen uptake by phytoplankton in the Southern Ocean is not fully resolved over an annual scale due to the lack of winter in situ measurements. In this stu...

The impact of light and nutrients (such as silicate and iron) availability on nitrogen uptake and primary production vary seasonally and regionally in the Southern Ocean. The seasonal cycle of nitrogen uptake by phytoplankton in the Southern Ocean is not fully resolved over an annual scale due to the lack of winter in situ measurements. In this stu...

Wherever measurements have been made bromoform was found to be ubiquitous in the surface ocean in pmolar-nmolar concentrations. These measurements show concentrations in coastal regions orders of magnitude higher than in the pelagic oceans. Its atmospheric presence is primarily due to its release from algae and rapid transport to the marine boundar...