Helmholtz Young Investigator Group SiDe-EFFECT

Marine Applied Research Laboratory


Understanding the IMPACTS of climate change and finding SOLUTIONS for climate change.

In the middle of a climate crisis, we must continue gaining knowledge about the effects of global warming on fragile ecosystems such as the polar regions, while at the same time moving from knowledge to action seeking to apply or knowledge to find ways to mitigate climate change.


The Marine Applied Research Laboratory aims to improve our understanding of the processes that lead to carbon sequestration in the ocean: from primary productivity at the surface to carbon export to the deep sea.
Building on our strong knowledge on primary productivity measurements, carbon and nutrient uptake quantification, biodiversity estimates, grazing experiments, and biogeochemical modelling we:

  1. Investigate the consequences of climate change in the Arctic Ocean for primary productivity, biodiversity and trophic transfer efficiency.
  2. Assess the potential of macroalgae for long-term carbon dioxide removal and storage in the ocean.


Current Projects:

1. Helmholtz Young Investigator Group “Silicic acid Decline Effect on Arctic Marine Ecosystems” SiDe- EFFECT (2021-2026)

Anthropogenic climate change is modifying the ocean at scales previously unimaginable. One of the most obvious changes is the rapid decline in Arctic sea ice during the past two decades. This has direct consequences on the Arctic microorganisms because more light is available, allowing increased net primary productivity (NPP) in some areas. However, even in an ice-free Arctic, NPP will not increase without limit. The amount of nutrients available in the euphotic zone at the beginning of spring will largely determine the total amount of annual new production. In addition, ocean warming causes changes in the winter mixed layer in the Northern Atlantic, causing the amount of silicic acid entering the Arctic Ocean to decline in the last decades. This will affect primary producers in their carbon uptake capacity and in their community composition, which will subsequently have cascading effects on zooplankton composition, fisheries, and carbon export.

The AIM of the SiDe-EFFECT project is to understand the consequences of declining silicic acid on the Arctic marine ecosystem and the responsible underlying mechanisms.

To understand how climate changes impacts the Arctic Ocean, we will combine novel and classical approaches to study phytoplankton physiology, biodiversity and zooplankton interactions and improve the accuracy of current model projections in our SiDe-EFFECT  Hemholtz Young Investigator Group. Our university partner is the Carl von Ossietzky Universität Oldenburg, and we are also collaborating with international and national institutions.

2. sea4soCiety- Sargassum (2021-2024)

In addition to improving our knowledge on the impacts of climate change in the polar regions, the Marine Applied Research Laboratory is also researching potential nature-based solutions to sequester CO2 to mitigate those impacts. We believe that in order to achieve the speed and scale needed to solve the climate crisis, we need to look for solutions in the ocean. In particular, from all the Ocean Carbon Dioxide Removal (OceanCDR) strategies we will investigate the potential of the floating macroalgae Sargassum to sequester carbon.

Sargassum fluitans and natans have an entirely pelagic life cycle, high carbon to nutrient ratios and they might produce recalcitrant exudates that are difficult to degrade. Therefore, pelagic Sargassum is a good candidate for carbon sequestration in the ocean if the carbon can permanently be stored or at least remain in the seafloor for a long period of time. To elucidate the carbon and nutrient cycling associated with pelagic Sargassum we will use a combination of growth experiments, in situ sampling, aerial monitoring with drones, and modelling. In the sea4soCiety-Sargassum project, part of the CDRmare research mission (https://cdrmare.de/en/) we will quantify the potential of Sargassum for Ocean CDR and explore its co-benefits considering social perception.

3. C-CAUSE (Chemical CArbon Utilization through Sargassum Economy) funded by SPRIN-D within the Carbon to Value Challenge. Phase I: May 2022 to May 2023.

Together with our partners from GEOMAR, Seafields and Carbonwave, and supported by BASF, our group at AWI will develop novel monitoring tools to quantify and verify the carbon sequestered by open ocean Sargassum seaweed aqua farms. The C-CAUSE consortium addresses one of the key challenges of decarbonizing – providing biological, renewable, carbon feedstocks for the chemical industry. We propose to use seaweed which requires no land, freshwater or artificial fertilizer and takes up carbon through photosynthesis. The vision is to create huge open ocean aquafarms of the fast-growing, free-floating seaweed Sargassum. To upscale Sargassum aquafarming for carbon sequestration, we need to find the optimal trade-off between a fast growth rate and a high carbon to nutrient ratio and apply innovative techniques to monitor large areas of the ocean.  

Our group will perform incubations adding the nutrients recovered through the processing steps performed after harvesting and measure carbon uptake and nutrient storage in the Sargassum biomass using stable isotopes. Our partners will process the seaweed to extract ethanol through fermentation and to produce bio methane through anaerobic digestion. The ethanol can be used to produce long-lived engineering plastics that store the carbon for decades and the methane can be used to fuel operations and make it a carbon negative approach that actively sequesters CO2 in valuable products.


Members of the Marine Applied Research Laboratory in August 2022.
From left to right: Nicola Schwehm (Environmental Engineer), Dr. Miriam Philippi (PostDoc), Dr. Julia Schnetzer (Project Manager), Dr. Lena Eggers (Technical assistant), front: Dr. Mar Fernández Méndez (Group leader)

Group Leader:
Dr. Mar Fernández-Méndez

Technical Assistance:
Dr. Lena Eggers

Dr. Miriam Philippi

Project Manager C-Cause Consortium Project SPRIND-D:
Dr. Julia Schnetzer

Environmental Engineer Seafields Solutions, guest scientist:
Nicola Schwehm