Till startsida
To content Read more about how we use cookies on gu.se

Marine geology projects

Sill fjords basin sediments, unique climate and environmental high resolution archives

Tröskelfjordars sedimentDespite the largely unanimous agreement that climate change is occuring and the adverse effects of marine pollution on the environment, there are still uncertainties and disagreements about the seriousness of the problems and the underlying causes. Separating natural processes from human-induced problems is not always easy, but the need to assess this is growing and becoming increasingly important.

Due to the special hydrographic and sedimentation conditions in micro tidal fjord basins, long sediment cores, with its rich content of well-preserved fossil fauna and flora and the isotope composition in these organisms, it is possible to study the effects of Tröskelfjordars sedimentclimate change. This can include information about what occurred during Roman times in about 2000 years ago, during the Middle Ages warming period between 800 and 1300 AD, the very cold period between 1350 and 1830, the so-called. “Little Ice Age”, and the climate of most recent times. What is very special about the Gullmar Fjord concerning past climate (besides providing answers to how climate change affects the ocean conditions) is that we have obtained information about changes in winter temperatures. Most other studies report land conditions with data from the summer by using plants as temperature indicators, for example annual tree rings and pollen but also stalactites and stalagmites (drip stone formations of in karst caves). In the sediment of the Gullmar Fjord, we get a winter signal, because the water exchanges in the fjord take place in winter and the temperature is preserved in the bottom water, as in a thermos, until the next winter's water exchange.

Tröskelfjordars sedimentThe results from similar fjord studies can also be used to show how pollution and environmental hazards have been introduced into the environment, how extensive the pollutants are and if they are reduced when measures are taken. The sediments can thus serve as a valuable and versatile environmental archive. Sediment studies also enable us to better understand future effects of both heating, cooling, pollution and environmental threats. Important tools, called environmental proxies, for studying climate and pollution include siliceous algae and resting cells from dinoflagellates (planktonic algae in the surface water), benthic single-celled amoebas with fossilazable shells, so called foraminifers and stable isotopes of carbon and oxygen in their shells, age determinations and climate data, both instrumental and historical.

More areas where similar research is conducted: Skagerrak, Kosterhavet, Havstens Fjord, Koljö Fjord, Byfjord, Sannäs Fjord, Dynekilen and Idefjord.

Selected publications:

Filipsson, H.L. and Nordberg, K., 2004: Climate variations, an overlooked factor influencing the recent marine environment. An example from Gullmar Fjord, Sweden. Estuaries, 27:867-880.

Harland, R., Nordberg, K. and Filipsson, H. L. 2010: A major change in the dinoflagellate cyst flora of Gullmar Fjord, Sweden, at around 1969/1970 and its possible explanation. In: J. A. Howe, W. E. N. Austin, M. Forwick and M. Paetzel. (Eds) Fjord Systems and Archives, Geological Society, London, Special Publications, 344, 77-84.

Filipsson H.L. & Nordberg, K., 2010: Variations in residence time and productivity during the last 2400 years in a Skagerrak fjord basin, inferred from benthic foraminiferal ∂13C and organic carbon. In: J. A. Howe, W. E. N. Austin, M. Forwick and M. Paetzel. (Eds) Fjord Systems and Archives, Geological Society, London, Special Publications, 344, 263-272.

Cossellu, M. & Nordberg, K., 2010: Recent environmental changes and filamentous algal mats in shallow bays on the Swedish West Coast – a result of climate change? Journal of Sea Research, 63:203-212.

Polovodova, I., Nordberg, K., and Filipsson, H.L., 2011: The benthic foraminiferal record of the Medieval Warm Period and the Recent Warming in the Gullmar Fjord, Swedish west coast. Marine Micropaleontology 81:95-106

Robijn, A., 2012. A 250-year long sediment record from the Sannäs Fjord, Swedish west coast – environmental changes reflected by benthic foraminifera and heavy metal concentrations. Department of Earth Sciences, University of Gothenburg, B702, ISSN 1400-3821, 31 pp.

Polovodova Asteman, I., Nordberg, K., Filipsson, H.L., 2013: The Little Ice Age: evidence from the sediment record in Gullmar Fjord, west coast of Sweden. Biogeosciences, 10:1275–1290.

Harland, R., Polovodova Asteman, I., Nordberg, K., 2013: A two-millennium dinoflagellate cyst record from Gullmar Fjord, a Swedish Skagerrak sill fjord. Palaeogeography, Palaeoclimatology, Palaeoecology, 392:247-260.

Polovodova Asteman, I., Nordberg, K., 2013: Foraminiferal fauna from a deep basin in Gullmar Fjord: the influence of seasonal hypoxia and the North Atlantic Oscillation. Journal of Sea Research 79:40-49.

Nordberg, K. and Robijn, A., 2015: Historien upprepar sig – Rapport från havsbotten. I Havet 1888, p 10-13. Havsmiljöinstitutet. ISBN: 978-91-982291-0-3. 83pp

Polovodova Asteman, I., Filipsson, H. and Nordberg, K. 2018: Tracing winter temperatures over the last two millennia using a NE Atlantic coastal record. Climate of the past 14:1097-1118.

Marine single-celled organisms as important tools for reconstructing changes in the marine environment

Mikroskopiska marina organismer som verktygMarginal marine environments and, in particular, estuarine zones represent dynamic systems characterised by both high primary production and natural variability. In addition, these areas are often highly urbanized and exposed to human impact leading to eutrophication, pollution and acidification of coastal waters. Fjords are a special type of estuaries with a transverse sill, which separates the bottom water of the fjord basin and the water from the open sea. The limited water exchange makes fjords especially sensitive to changes in water exchange (involving stagnation periods), climatic variations (e.g. NAO) and pollution.

Marine microscopic single-celled organisms like benthic foraminifers,Mikroskopiska marina organismer som verktyg diatoms and dinoflagellates are highly abundant in fjord environments. Diatoms and dinoflagellates are important primary producers, while benthic foraminifera are heterotrophic protists that constitute a large part of the benthic biomass and play a major role in the organic matter consumption at the sea floor. Being sensitive to environmental changes, all these organisms rapidly respond to short-term variations in Mikroskopiska marina organismer som verktygtemperature, salinity, pH, dissolved oxygen and nutrient supply by changing their abundances, diversity, dominance, species composition or microhabitat preferences. Therefore, by studying recent distribution of foraminifera, diatoms and dinoflagellates in Swedish fjords, we obtain important information about their autoecology. This can be further applied to their fossil counterparts helping the interpretation of sediment records reflecting the past on annual, decadal, centennial and millennial time scales.

Selected publications:

Gustafsson, M. & Nordberg, K., 2001: Living (stained) benthic foraminiferal response to primary production and hydrography in the deepest part of the Gullmar Fjord, on the Swedish west coast; including comparisons with Höglund´s material from 1927. Journal of Foraminiferal Research 31:2-11.

McQuoid, M., Godhe A. & Nordberg, K., 2002: Viability of phytoplankton resting stages in coastal Swedish sediments. European Journal of Phycology 37:191-201.

McQuoid, M. and Nordberg, K., 2003: The diatom, Paralia sulcata, as an environmental indicator species in coastal sediments. Estuarine, Coastal and Shelf Science 56: 339-354.

Nordberg K., Filipsson H.L., Linné P. & Gustafsson M., 2009: Stable isotope evidence for the recent establishment of a new, oportunistic foraminiferal fauna within Gullmar Fjord, Sweden Marine Micropaleontology, 73:117-128.

Harland, R. & Nordberg, K., & Robijn, A., 2013: Latest Holocene dinoflagellate cyst records from the west coast of Sweden and their impact on the interpretation of the environmental change. In Lewis, J. M., Marret, F. & Bradley, L. (eds). Biological and Geological Perspectives of Dinoflagellates. The Micropalaeontological Society, Special Publications. Geological Society, London, 43-54.

Harland, R., Polovodova Asteman, I., Nordberg, K., 2013: A two-millennium dinoflagellate cyst record from Gullmar Fjord, a Swedish Skagerrak sill fjord. Palaeogeography, Palaeoclimatology, Palaeoecology, 392:247-260.

Polovodova Asteman, I., Hanslik. D., Nordberg. K., 2015. An almost completed pollution-recovery cycle reflected by sediment geochem and benthic foram assemblages in a Swedish–Norwegian Skagerrak fjord. Marine Pollution Bulletine 95:126-140.

Polovodova Asteman, I., Nordberg, K., 2017: A short note on a present-day recovery in the formerly heavily polluted Idefjord (Sweden/Norway). Marine Pollution Bulletin 123:227-231.

Nordberg, K., Polovodova Asteman, I., Gallagher, T.M., Robijn, A., 2017: Recent oxygen depletion and benthic faunal change in shallow areas of Sannäs Fjord, Swedish west coast, Journal of Sea Research, 127:46–62.

Leisureboats impact on the marine environment, the Sannäs Fjord Project

SannäsprojektetLeisureboats impact on the marine environment has been a research project which began in 2008, focusing on environmental effects and the spread of anti-fouling paints from boat bottom painting. Investigations of both heavy metals and organic pollutants have been carried out in the Sannäs Fjord parallel to oceanographic measurements. A flush platform with a purification plant (Stages 1, mechanical separation, and 2, purification facility with precipitation of metals and filtration of organic compounds through activated charcoal) Sannäsprojektetwas built 2009 in Sannäs marina. This facility is also used for courses and demonstrations. Scientific results are now published in international journals with per-review systems.


Johansson, P., 2010. Water exchange above sill level in the Sannäsfjord, west coast of Sweden, Department of Earth Science, Göteborg, University of Gothenburg, B591, 37 p.

Robijn, A., 2010. Heavy metal concentrations as a relative age marker in recent marine sediment cores along the Swedish west coast. Department of Earth Science, Göteborg, B608, 25 p.

Nordberg K, Bornmalm L, Cato I, Arneborg L, Björk G and Robijn A. 2012. Sannäsfjorden - en studie av hydrografisk, bottendynamisk och miljökemisk status. Department of Earth Sciences, University of Gothenburg.C95, ISSN 1400-383X. 50p.

Ödalen, M., 2012. Oxygen deficiencies and environmental issues related to hydrography in the Sannäs fjord, west coast of Sweden. Dept. of Earth Science, Göteborg, B680, 41 p.

Robijn, A., 2012. A 250 years sediment record from the Sannäsfjord, Swedish west coast, environmental changes reflected by benthic foraminifera and heavy metal concentrations. Department of Earth Science, Göteborg, B702, 27 p.

Björk, B., Nordberg, K., Arneborg. L, Bornmalm, L., Harland, R., Robijn, A. and Ödalen, M. 2017: Seasonal oxygen depletion in a shallow sill fjord on the Swedish west coast. Journal of Marine Syst. 175:1-14.

The impact of recreational boats on the coastal environment, a project on sustainable boating and the coexisting industries for a good marine environment

Fritidsbåtars inverkan på skärgårdsmiljönThe project is a unique and close cooperation between University of Gothenburg, the County Administrative Board, the Swedish Agency for Marine Water Management (HaV), the Transport Agency, the The Geological Survey of Sweden (SGU), the Region Västra Götaland (VGR), Research Institutes of Sweden - Bioscience and Material (RISE), municipalities and several other organizations. By using the areas of Sannäs Fjord and Grebbestad, two adjacent territories in northern Bohuslän, which can serve as model areas to provide scientifically well-substantiated evidence of the effects of recreational craft exhaust gases in the water for improved planning of marine environments at local, regional and national level. In the Sannäs Fjord, significantly elevated levels of polycyclic aromatic hydrocarbons (PAH)Fritidsbåtars inverkan på skärgårdsmiljönare found in the sediments where there are no significant sources of pollution, other than pleasure boats. Within the project we will continue scientific measurements and analysis to create models of distribution for exhaust-related substances in the water, in sediments and in blue mussels and oysters. The project also includes social science analysis, including attitudes among boat owners and representatives of various industries related to boats, tourism and production of marine food. The results are weighed into GIS-based models. We provide documentation for improved marine planner tools and intend to develop user-friendly GIS programs for the purpose. Cooperation with the Transport Agency also opens up, if necessary, possibilities for legislative proposals.


Nordberg, K., 2017: Ostron mäter föroreningar från båtavgaser. Västerhavet 2017, p 14-15. Havsmiljöinstitutet. ISSN 1104-3458. 24pp.

Page Manager: Bo Johannesson|Last update: 10/25/2018

The University of Gothenburg uses cookies to provide you with the best possible user experience. By continuing on this website, you approve of our use of cookies.  What are cookies?