The project cruise (HE578) is one of the core sampling campaigns of the FACTS project, addressing the geographical issue of microplastic transport from the temperate waters of the southern North Sea to the Arctic waters of the Barents Sea. The ship chosen for this expedition is the Heincke, a 55 meters long research vessel operated by the Alfred Wegener-Institute Helmholtz Centre for Polar and Marine Research (AWI), equipped with all necessary equipment and facilities necessary for a scientific expedition and providing accommodation for up to 12 scientists.
The cruise started from Bremerhaven on June 04th heading North to collect samples for microplastic pollution in several coastal and off-shore stations located in Norway, the Shetland Channel, stretching up North and touching the most northern sampling point in an area located in the proximity of Bjørnøya (Bear Island), a small remote island located between Norway and The Svalbard archipelago.
The activities onboard the vessel were coordinated by Dr. Gunnar Gerdts (AWI), chief scientist of the cruise and one of the most prominent researchers in microplastic science worldwide. Oceanographic parameters were recorded to identify different water masses and their related physical features and biological activities using a CTD unit. Moreover, surface and deep-water currents were also measured using a lowered Acoustic Doppler Current Profiler (ADCP).
In order to gain a holistic and comprehensive view of the complex mechanisms involved with microplastic transport in the marine environment, a wide array of sampling methods and strategies were employed during the cruise. Microplastics in the water column were collected at several depths using a Rosette sampler (Dr. Giuseppe Suaria and Dr. Andrea Paluselli; Institute of Marine Sciences of the Italian Research Council ISMAR-CNR, Italy) and in-situ pumps, large-volumes filtering devices deployed at multiple depths, down to several thousands of meters (Dr. Karin Zonneveld; Centre for Marine and Environmental Sciences, University of Bremen - MARUM). These samples will fill the knowledge gaps on how the microplastic particles are distributed along the water column and if there are specific accumulation areas, e.g. at the interface between different water masses. Furthermore, the water surface was investigated by towing a catamaran equipped with a neuston net and a novel filtering system driven by an air pump and capable to filter water down to 10 micrometres (Dr. Gunnar Gerdts, Hannah Jebens, Fangzhu Wu; AWI, Germany). Marine aggregates were collected using Marine Snow Catchers (Jon Roa and Christine Fink; Helmholtz Centre for Ocean Research – GEOMAR, Germany), large samplers deployed at specific depths collecting water and sinking "snow" particles in a special bottom area. The scientist could then secure these aggregates for further analysis to understand if microplastics aggregate with other organic matter (marine snow).
The sampling was carried out also during navigation to fill the knowledge gaps between transects using a novel filtering apparatus (AAU – COMPASS – COntinuous Microplastic Automatic Sampling System – Alvise Vianello; Aalborg University – AAU) which allows to collect and filter large volumes of water down to 10 micrometres from the ship's "moon pool". Microplastics were also sampled in deep-sea marine sediments using a multi corer (MUC), deployed down to the sea-bottom to collect several sediment cores simultaneously (Gerard Versteegh; AWI, Germany) to investigate the microplastic pollution reaching the seafloor and its stratification. The sampling activities also included aerosol monitoring, carried out with high volume aerosol samplers (Christoph Georgi; Technical University of Berlin – TUB), mobile impactors for sampling small volumes, and custom made air samplers developed specifically for airborne microplastic monitoring (Dorte Herzte – Norwegian Institute of Air Research – NILU). This complementing dataset will allow us to understand better if the atmospheric deposition of microplastics plays a significant role in polluting our oceans.
The scientific expedition concluded on July 7th when the RV Heincke reached Bremerhaven harbour's port after collecting hundreds of samples from different environmental compartments. The samples will now be analysed in the following months by the FACTS consortium, providing new insights on the sources, transport, occurrence, and fate of small microplastics in northern European waters.
For more information: https://jpi-oceans-facts.eu/