uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Seasonal variation of astaxanthin production in a changing pelagic ecosystem
Department of Systems Ecology, Stockholm University.
Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Ecological Botany.
Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Ecological Botany.
(English)Manuscript (preprint) (Other academic)
Abstract [en]

The carotenoid pigments of mesozooplankton communities in the Baltic Sea area were investigated in a large-scale survey. Ninety-nine percent of the zooplankton carotenoid concentrations consisted of astaxanthin and only 1% of canthaxanthin. We recorded large seasonal differences in astaxanthin concentrations, but no apparent patterns in the regional distribution within the Baltic Sea proper. Astaxanthin levels were lowest in summer when zooplankton feeding and growth rates are highest. In the cold season astaxanthin concentrations were three to four times higher than in summer and the proportions of astaxanthin esters were much higher than in summer. This suggests that astaxanthin is necessary especially in winter for the antioxidant protection of storage lipids. The seasonal cycles of astaxanthin was strongly intertwined with seasonal environmental conditions and changes in zooplankton community composition. Large differences between cladoceran- and copepod-dominated communities were were discovered. The abundances of the cladoceran genera Bosmina, Evadne and Podon were strongly negatively correlated with community concentrations of all forms of astaxanthin. Among the copepods, Temora longicornis and Pseudocalanus acuspes had the highest affinities with astaxanthin and Acartia spp. the lowest. The proportion of astaxanthin esters in the mesozooplankton of the Baltic Sea proper was on average 35%, which is lower than normally reported for pelagic crustaceans. This may indicate starvation of zooplankton and low nutritional value as astaxanthin source for predators in the Baltic Sea proper. Climate change scenarios for the area predict developments towards higher water temperature and lower salinity in the near future and this may lower the food quality for planktivorous fish if the abundances of Bosmina spp. and Acartia spp. increase at the cost of more nutritious copepods with higher astaxanthin concentrations. Because of their small size these taxa are normally avoided as prey by the major planktivorous fish, herring and sprat, in the Baltic Sea proper. However, when the abundances of larger zooplankton decrease by the ongoing bottom-up and top-down pressures on the zooplankton community, which already has happened in the case of Pseudocalanus acuspes, this may have consequences for the transport of astaxanthin to higher trophic levels.

Keyword [en]
Baltic Sea, pelagic, phytoplankton regime shift, zooplankton
URN: urn:nbn:se:uu:diva-130141OAI: oai:DiVA.org:uu-130141DiVA: diva2:346644
Available from: 2010-09-02 Created: 2010-09-02 Last updated: 2011-01-10
In thesis
1. Dynamics of astaxanthin, tocopherol (Vitamin E) and thiamine (Vitamin B1) in the Baltic Sea ecosystem: Bottom-up effects in an aquatic food web
Open this publication in new window or tab >>Dynamics of astaxanthin, tocopherol (Vitamin E) and thiamine (Vitamin B1) in the Baltic Sea ecosystem: Bottom-up effects in an aquatic food web
2010 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The thesis combines laboratory experiments and field expeditions to study production, transfer and consumption of non-enzymatic antioxidants and thiamine in an aquatic food web. In particular, I (1) documented spatial and seasonal variation of tocopherols and carotenoids in the Baltic Sea pelagic food web, and (2) examined the effects of abiotic and biotic factors on tocopherol, carotenoid and thiamine concentrations in phytoplankton, zooplankton and fish.

Moderate differences in temperature and salinity affected α-tocopherol, β-carotene and thiamine production in microalgae. Furthermore, the results suggest that acute stress favors the expression of non-enzymatic antioxidants rather than enzymatic antioxidants. Because production of α-tocopherol, β-carotene and thiamine differ markedly between microalgae, the availability of non-enzymatic antioxidants and thiamine is likely to be highly variable in the Baltic Sea and is difficult to predict.

The transfer of non-enzymatic antioxidants from phytoplankton to zooplankton was biomass dependent. The field expeditions revealed that phytoplankton biomass was negatively associated with α-tocopherol concentration in mesozooplankton. Thus, increased eutrophication of the Baltic Sea followed by an increase in phytoplankton biomass could decrease the transfer of essential biochemicals to higher levels in the pelagic food web. This could lead to deficiency syndromes, of the kind already observed in the Baltic Sea. Astaxanthin is synthesized from precursors provided by the phytoplankton community. Thus biomass dependent transfer of astaxanthin precursors from phytoplankton to zooplankton could be responsible for astaxanthin deficiency in zooplanktivorous herring. Astaxanthin in herring consists mostly of all-Z-isomers, which are characterized by low bioavailability. Therefore, astaxanthin deficiency in salmon could be explained by the low concentration of this substance and its isomeric composition in herring.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2010. 47 p.
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 762
Baltic Sea, carotenoids, astaxanthin, tocopherols, Vitamin E, thiamine, Vitamin B1, pelagic food web, eutrophication, M74, phytoplankton, zooplankton, sprat, Sprattus sprattus balticus, herring, Clupea harengus, salmon, Salmo salar, cod, Gadus morhua, High Performance Liquid Chromatography (HPLC), electrochemical detection (ECD)
urn:nbn:se:uu:diva-130143 (URN)978-91-554-7878-0 (ISBN)
Public defence
2010-10-15, Lindahlsalen, Norbyvägen 18, EBC, Uppsala, 10:00 (English)
Available from: 2010-09-23 Created: 2010-09-02 Last updated: 2011-01-10

Open Access in DiVA

No full text

By organisation
Ecological Botany

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 418 hits
ReferencesLink to record
Permanent link

Direct link