FAABulous: Future Arctic Algae Blooms - and their role in the context of climate change

Informations

Funding country

Norway

Acronym

-

URL

-

Start date

1/1/2015

End date

12/31/2021

Budget

2,006,499 EUR

Fundings

Abstract

The Arctic environment is currently changing at an unprecedented rate, leading to complex and hitherto poorly understood consequences for the marine ecosystems. Small microalgae represent the basis of the marine food web, and are affected by these changes in multiple ways: (1) altered light conditions owing to a decrease of sea ice extent and thickness, (2) ocean acidification (OA), resulting from an uptake of anthropogenic CO2 into the water, (3) invasion of more temperate species from the south through increased transport of water masses from lower latitudes and higher temperatures in Arctic waters. Together, these three processes are expected to change the timing, species composition, productivity, and food quality of Arctic algal blooms, with far-reaching implications for the entire ecosystem. This project aimed at studying the combined effect of these three processes on Arctic algal blooms in sea ice and water, with a special focus on the control of the onset and development of a bloom. This has been done by combining (i) extensive field studies in two Arctic fjord systems with contrasting environmental characteristics, (ii) experiments to study the combined effect of increased light and CO2 on natural algae communities and single species, and (iii) developing models that allow us to study the environmental control of blooms. In September 2015, we established ocean observatories in van Mijenfjorden and Kongsfjorden in Svalbard that provided us with continuous measurements of the physical and chemical conditions throughout the year. Due to a collaboration with AWI, we were also able to add autonomous water samplers to these installations that have collected a unique set of phytoplankton and water chemistry samples from the first year of deployment. The ocean observatories were turned over in September 2016, and the one in Van Mijenfjorden was retrieved finally in August 2017 (the observatory in Kongsfjorden is continued under the auspices of UiT and SAMS). Seasonal data were collected during 11 cruises between Sept 2015 to August 2017, of which eight were FAABulous project cruises, while the other three were organized by collaborators at UiT and UNIS. In addition, we carried out a sea ice sampling campaign in Van Mijenfjorden from March to May 2017, with an extended stay there during late April/early May. In Kongsfjorden, our collaboration partners from AWI spent altogether almost six months in Ny-Ålesund in 2016, 2017 and 2018 to follow the algae spring bloom in detail. Seasonal dynamics of zooplankton and sea ice meiofauna were studied within several MSc projects that were also supported by Arctic Field Grants. In April 2018, several FAABulous researchers were involved teaching the UNIS course on Sea ice ecology (led by Janne Søreide), including another field trip to Van Mijenfjorden with additional sampling. To increase our understanding how photosynthetic microalgae overwinter at high latitudes, we carried out experiments addressing their photophysiological state during the Polar night in January and December 2015. A peer-reviewed article about this was published in 2018. The combined stress of high light and ocean acidification on key species was studied in laboratory experiments in Bremerhaven during autumn 2016, including not only effects on physiological characteristics, but even on gene transcription level. In situ experiments with natural sea ice algal and phytoplankton communities during the sea ice campaign in spring 2017 allowed us to compare these findings with the natural situation. This is being dealt with in the third article of Ane Cecilie Kvernvik PhD thesis that she defended successfully in March 2019 in Longyearbyen. The 3D version of the FVCOM model for the west Spitsbergen area is operational now. To use it for addressing project-related questions as planned, however, we are dependent on additional funding. FAABulous project results have been presented at international conferences in Norway, Canada, Switzerland, Italy and Croatia. Eva Leu and Ane Cecilie Kvernvik were co-chairing a session about changes in algal blooms during the Arctic Change meeting in Quebec City together with Canadian colleagues (Dec 2017). In October 2020, the final project workshop was held online in conjunction with an international scientific symposium titled Environmental control of algal bloom phenology in a pan-Arctic perspective (19-23 Oct). It brought together 70 participants from 9 countries, including many early career researchers, and was organized in collaboration with ARCTOS and three CAO-projects funded by NERC and BMBF. One day was dedicated to presenting the highlights from FAABulous project results to a wider scientific audience. At the end of the official project period, 11 publications are published, 2 manuscripts are currently in revision, 6 more are in preparation, and additional 6 are being planned - partly dependent on extra funds.