DBL-OA · Living in the diffusive boundary layer of seaweeds a potential refuge habitat from ocean acidification
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2017-06-15 → 2020-06-14
- EU contribution
- €264,110
- Participants
- 2
- Scheme
- MSCA-IF
Lines connect the coordinator with its partners.
Results in brief
Living in the diffusive boundary layer of seaweeds a potential refuge habitat from oceanacidification
In temperate coastal communities, seaweeds are ecosystem engineers that are of ecological importance, providing food an habitat for numerous benthic species as well as important ecosystem services such as carbon fixation and coastal stabilization. In addition to these roles, they also modify their local chemical (e.g. pH) and physical (e.g. water flow) environment because of their metabolism and structure. These modifications might offset the environmental changes generated by global changes like ocean acidification (OA), a worldwide phenomenon leading to seawater pH decrease and changes in carbonate chemistry which can affect marine organisms, particularly calcifying ones. The main objective of this project DBL-OA was to investigate the capacity of brown seaweeds in providing favorable micro-environments to help calcareous taxa in coping with OA. At the surface of all seaweeds, there is a thin (mm) layer of seawater called the “diffusive boundary layer” (DBL) whose chemistry, including pH, is controlled by the seaweed’s metabolism. Depending on algal morphology and hydrodynamics characteristics, the DBL thickness varies, forming a sometimes thick (6 cm) DBL associated with the seaweed canopy, thus providing more or less complex microhabitats for associated species. The projects aimed at understanding the link between the metabolic responses of seaweeds, the shaping of chemical micro-environment at different scales (blade and canopy) and the consecutive mitigation of environmental stress on the organisms living in theses specific habitats (e.g bryozoans on blades and coralline algae in understory), in different scenario of global warming and OA.
Data: CORDIS, © European Union
Project objective
The world’s oceans are becoming more acidic due to the sustained absorption of excess atmospheric CO2. Ocean acidification (OA) is predicted to affect the physiology of marine organisms at a specific level with calcifying species being particularly threatened because low pH impairs the formation, and causes dissolution, of their calcite skeletons. In temperate coastal communities, seaweeds are ecosystem engineers that modify their local chemical (e.g. pH) and physical (e.g. water flow) environment; this modification might offset the negative effects of OA on calcifiers. Brown seaweeds (Order Fucales) are ecologically dominant primary producers of temperate coastal seas, supplying food and habitat for calcifying fauna living on their blade surface (e.g. bryozoans, tube worms) but also forming dense canopies sheltering understory calcareous algae. At the surface of all seaweeds, there is a thin (mm) layer of seawater called the “diffusive boundary layer” (DBL) whose chemistry, including pH, is controlled by the seaweed’s metabolism. Depending on algal morphology, the DBL thickness varies, forming a sometimes thick (6 cm) DBL associated with the seaweed canopy, thus providing more or less complex microhabitats for associated species. The proposed program will combine field observations with rigorous laboratory experiments to examine the ability of morphologically distinct seaweeds to engineer their hydrodynamic and pH environment, and determine the resultant effects on the growth and physiology of associated invertebrates and calcifying algae. To know species interactions under environmental change is important to understand community functioning in a future ocean. This innovative project will compare the generality of responses by conducting experiments using the same novel methods in Fuclean communities from the southern (Tasmania) and northern (Germany) hemispheres, thereby elucidating the extent to which seaweed-based ecosystems can provide natural refugia from OA.
Original text from CORDIS.
Participants
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Data: CORDIS, © European Union