Expeditions
![[Translate to English:] R/V Aurora](/fileadmin/_processed_/6/b/csm_Aurora_47499f55fb.png "[Translate to English:] R/V Aurora")
Further Information
Aurora-HABBAL
Aarhus-Bornholm-Aarhus (Baltic Sea), R/V Aurora, 11.09.2023-17.09.2023
The project is investigating the distribution expansion of the harmful microalgae species Alexandrium pseudogonyaulaxinto the Baltic Sea.
MIDIDARC & MarineBasis-Nuuk
MIDIDARC & MarineBasis-Nuuk
R/V Sanna, Nuuk, Greenland (23.04.2023-01.05.2023)
MIDIDARC aims to analyze the phycosphere microbiome of Arctic diatoms to reveal their diversity and understand the role of prokaryotes in maintaining diatom growth and spring bloom formation. To this end, AWI scientists Sylke Wohlrab and Jakob Giesler participated in this year's MarineBasis-Nuuk Monitoring Expedition led by Thomas Juul-Pedersen from the Greenland Climate Research Centre at the Greenland Institute of Natural Resources. In addition to obtaining samples for their research, the AWI scientists were given the opportunity to gain insight into the work of their marine biologist colleagues in Greenland, as well as the long-term marine monitoring program MarineBasis-Nuuk.
FjordChange
Investigation of changes in oceanographic properties as well as plankton diversity and activities and their effects on primary production and biogeochemical fluxes along a gradient of atlantification.
Global change is causing fundamental environmental changes in the Arctic. The fjords of Svalbard are exposed to an increasing influence of warm, salty water masses from the North Atlantic (Atlantification). In addition, increased glacier melt leads to an increasing freshwater inflow within the fjords. The study area includes 4 fjord systems that are affected to varying degree by atlantification: The van Mijenfjord (south) and the now year-round ice-free Kongsfjord (northwest) are severely affected. The Wijdefjord in the north shows significantly less atlantification as well as ice cover in winter, while the Rijpfjord (northeast) is under the influence of polar water.
The FjordChange project addresses the impact of the increasing atlantification of the waters and fjords around Spitsbergen on the interactions of ocean and plankton composition and their ecosystem functions. We combine oceanographic, taxonomic, bio-optical and metagenomic approaches from the water column as well as from the sediment, so that we can also assess the changes with historical data on the ecosystem state. The results will be used to estimate and quantify effects on the ecosystem caused by accelerated atlantification and climate change impact.
Lead Scientist Ecological Chemistry:
ArcWatch
Interaction and feedbacks between ocean structure and dynamics, sea ice physics, biogeochemistry, and biodiversity of the Arctic Ocean.
Organic compounds in the Arctic Ocean and the deep Atlantic Ocean are derived from marine algae and from a substantial input by the large Arctic Rivers. For us, ArcWatch is the continuation of the year-round drift experiment MOSAiC (2019/2020). Based on previous data, we want to elucidate, if the amount of dissolved organic compounds in the Arctic Ocean changed over the last decades. We also aim at quantifying the contribution of terrestrial organic matter because it represents a substantial component in the marine carbon cycle. Moreover, we want to verify previous observations on organic matter aggregation (cf. HAFOS expedition).
Participants from the Section Ecological Chemistry:
Boris Koch
Island Impact
Extensive open water phytoplankton blooms occur along the flow of the southern Antarctic Circumpolar Current downstream of the island South Georgia. The sources and magnitude of iron (Fe) inputs fueling productivity in these land-remote areas are poorly known. These substantial algal blooms require significant Fe inputs, but the actual Fe supply mechanisms and their relative importance for primary production and biogeochemical processes along the flow of the southern Antarctic Circumpolar Current remain largely unconstrained. Using our novel ultra-clean sampling system, we
- characterized the trace metal distribution patterns (Fe, Mn, Zn, Co, Cu), stocks and origin along the water column
- measured primary and bacterial production rates in the euphotic zone
- determined pico- and nanoplankton composition at 20 m depth
- assessed Fe uptake rates, trace metal quotas, photophysiological status and in-situ diatom species-specific growth rate at 20 m depth
- determined the Fe bioavailability of different Fe sources through 24h incubation experiments
- performed Fe-Mn-vitaminB12-addition experiments with various phytoplankton assemblages
- measured nutrient distribution profiles
Participants from Ecological Chemistry:
Scarlett Trimborn
Florian Koch
Christian Völkner
Jasmin Stimpfle
Kai-Uwe Ludwichoswki
Matthias Woll
Frederik Bussmann
HAFOS long-term time series
Long-term time series in the central Weddell Sea.
The biological pump in the Southern Ocean and its transport of particulate and dissolved organic compounds from the sea surface to the seafloor are important regulators of long-term carbon storage. The composition and distribution of organic compounds is controlled by nutrients, primary production and microbial activity, water mass mixing, degradation, and aggregation processes. We aim to understand which organic molecules drive aggregation in the Southern Ocean and thereby affect the sequestration of atmospheric CO2. In collaboration with the Environmental Research Centre Leipzig (UFZ).
Participants from the Section Ecological Chemistry:
Jan Tebben
Kai-Uwe Ludwichowski
Martin Graeve
Boris Koch
FjordFlux
Impact of subantarctic glacier melt on the coastal marine ecosystem.
FjordFlux will describe flux dynamics of organic matter (OM) in the Patagonian Cold Estuarine System (PCES) under melt conditions, to understand ecosystem functioning. The region, still considered as "pristine", is under increasing climate change and anthropogenic pressure. FjordFlux will obtain spatial information on the current environmental state by combining results from physical hydrography (e.g., patterns of coastal runoff) and chemistry to reveal terrestrial and marine sources of nutrients, OM, freshwater, and the distribution of greenhouse gases of the PCES. The effect of local flux patterns on planktonic and benthic community composition and functionality will be surveyed in fjords, differing in their state of deglaciation and eutrophication and adjacent areas. FjordFlux follows 25 years after the Victor Hensen Magellan cruise, serving as baseline to detect the state of change. The results support the initiative to establish marine terrestrial long-term observations in the Beagle Channel.
PHYCOB
The Black Sea is a unique marine system due to its isolation from the world's oceans. It is influenced by a large drainage basin, resulting in low salinity and vertical stratification of the water column. Especially the latter is an ideal condition for the growth and proliferation of marine dinoflagellates, including many toxic species. The phytoplankton diversity of the Black Sea has been studied by morphological characteristics since the middle of the 20th century. Approximately 1600 species are listed in the Black Sea phytoplankton checklist, 49 of which are described as toxic in other marine areas. However, there is almost nothing known about the actual occurrence of toxic phytoplankton species and their associated toxins in the Black Sea. This information deficit is becoming an increasingly problematic issue for the young mussel aquaculture sector, because mussels as filter feeders can take up and accumulate marine biotoxins from the plankton and thus represent a health risk for shellfish consumers. The aim of this research project is to determine the presence of toxic algae and their toxins in the western Black Sea, as well as to investigate their distribution in dependence on bio-optical, biogeochchemical and oceanographic parameters.
ReHaDiCC
Investigating the effect of global warming on the occurrence of toxic microalgae and phycotoxins in the Arctic.
The Arctic region is heavily impacted by global warming, which has an influence on the growth of planktonic microalgae that are the base of the marine food web and thus have a huge importance for the entire marine ecosystem. A higher water temperature, increased nutrient availability, and stratified water column generally promote growth of dinoflagellates, which can be problematic as this groups harbors many toxigenic species that produce a multitude of different marine phycotoxins. These toxins can enter the marine food web by trophic transfer and have deleterious effects on top predators as seabirds, marine mammals, and even humans. Whereas the occurrence of HAB species in the Arctic have been well documented for Alaska, West Greenland, Iceland, and the Chukchi Sea, hardly any data are available for East Greenland and Svalbard. The following research objectives were addressed:
1) Determination of the presence of toxigenic plankton species in coastal waters of East Greenland and Svalbard.
2) Assessment of phycotoxins presence in the study area.
3) Establishment of monoclonal cultures of potentially harmful algal species for subsequent physiological laboratory experiments under different temperature and pH regimes.
4) Taxonomic and phylogenetic characterisation of these cultures as well as their phycotoxin profiles.
HE516
R/V Heincke Bremerhaven-Bremerhaven (11.07.2018-12.08.2018)
Shellfish poisoning caused by azaspiracids (AZA) is a relatively recent phenomenon, which was first described in 1995, after 8 people became sick in the Netherlands after the consumption of Irish shellfish. These shellfish poisonings were caused by toxins produced by a number of nanoplanktonic species of the family Amphidomataceae. Although recent research results show that these species have a worldwide distribution, Ireland to this day remains the most affected country in the world by these shellfish poisonings. An evaluation of all currently available data leads to the hypothesis that Amphidomataceae, unlike many other toxic algae, are pelagic plankton of the open sea, which accumulate in specific cases by currents and winds at West coasts. With the present proposal, this hypothesis shall be tested by an integrated data set comprising oceanographic, bio-optical, meteorological, plankton and sediment data accompanied by taxonomic determinations, toxin measurements and Irish monitoring data.
GreenHAB II
R/V Maria S. Merian: St. John’s, Canada-Nuuk, Greenland (25.06.2017-19.07.2017)
The project “GreenHAB II” expedition will investigate the interactions between hydrography, bio-optics, and planktonic composition (especially toxigenic algae and their toxins) in combination with metagenomic approaches in fjords of West Greenland as well as along a latitudinal transect along the West Greenland coast. These fjords differ in their ice cover, glacial melt water runoffs, and history. The results shall be used to estimate quantifiable effects on the ecosystem which are driven by an accelerated glacial melt water runoff. The occurrence of toxigenic algal species which can be favored by decreasing salinity and increasing temperature shall be investigated with chemo-analytical, metagenomic, and bio-optical methods. In addition, sediments shall be examined for resting stages (cysts) of toxigenic planktonic species in order to estimate future population dynamics, including range expansions as waters warm. Levels of algal toxins shall be determined in algal material and the water column, partly directly on-board.
In cooperation with the ICBM, Universität Kopenhagen, WHOI, Universidad Mayor und PUC Santiago de Chile.
UTH16
The aim of the expedition to the Limfjord (June 2016) was to study the plankton community in the fjord system, which on the one hand represents a separated water body, but on the other hand it has a connection with both the North Sea in the west and the Baltic Sea in the east. Water, plankton and sediment samples were taken during the entire expedition to investigate not only the plankton composition in the water column, but also sediments (cysts) in the sediment. This expedition was a collaborative project with scientist from Copenhagen University in Denmark and participation with researchers from Argentina, Bulgaria and Finland.
LightHAB
Understanding of HAB dynamics by assessmentof of oceanographic and hydrographic conditions, bio-optical sensing. Determination of biodiversity of toxigenic phytoplankton and trophic transfer of toxic dinoflagellates to their protistan grazers. Site comparison among differnt fjord systems.
In cooperation with the ICBM.