EGU General Assembly 2020
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Effects on hydrodynamics and ecological costs of climate change and tidal stream energy extraction in a shelf sea

Michela De Dominicis1, Judith Wolf1, Dina Sadykova2,3, Beth Scott2, Alexander Sadykov2,3, and Rory O’Hara Murray4
Michela De Dominicis et al.
  • 1National Oceanography Centre, Liverpool, UK (
  • 2Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
  • 3School of Biological Sciences, Queen's University Belfast, Belfast, UK
  • 4Marine Scotland Science, Aberdeen, UK

The aim of this work is to analyse the potential impacts of tidal energy extraction on the marine environment. We wanted to put them in the broader context of the possibly greater and global ecological threat of climate change. Here, we present how very large (hypothetical) tidal stream arrays and a ''business as usual'' future climate scenario can change the hydrodynamics of a seasonally stratified shelf sea, and consequently modify ecosystem habitats and animals’ behaviour.

The Scottish Shelf Model, an unstructured grid three-dimensional ocean model, has been used to reproduce the present and the future state of the NW European continental shelf. While the marine biogeochemical model ERSEM (European Regional Seas Ecosystem Model) has been used to describe the corresponding biogeochemical conditions. Four scenarios have been modelled: present conditions and projected future climate in 2050, each with and without very large scale tidal stream arrays in Scottish Waters (UK). This allows us to evaluate the potential effect of climate change and large scale energy extraction on the hydrodynamics and biogeochemistry. We found that climate change and tidal energy extraction both act in the same direction, in terms of increasing stratification due to warming and reduced mixing, however, the effect of climate change is ten times larger. Additionally, the ecological costs and benefits of these contrasting pressures on mobile predator and prey marine species are evaluated using ecological statistical models.

How to cite: De Dominicis, M., Wolf, J., Sadykova, D., Scott, B., Sadykov, A., and O’Hara Murray, R.: Effects on hydrodynamics and ecological costs of climate change and tidal stream energy extraction in a shelf sea, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-11619,, 2020

Comments on the presentation

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Presentation version 1 – uploaded on 01 May 2020
  • AC1: Comment on EGU2020-11619, Rory O'Hara Murray, 04 May 2020

    Nice work: so we should be designing tidal stream layouts to counteract/mitigate some detrimental effects predicted by climate change (such as sea level rise)? 

    • AC2: Reply to AC1, Michela De Dominicis, 05 May 2020

      Mitigation of sea level rise (in some cases) can be considered as a positive side effect, but a tidal stream array should not be designed to achieve that. The maximum level of marine energy extraction, while minimizing environmental impacts, should be the priority.

  • CC1: Comment on EGU2020-11619, Sam Fredriksson, 05 May 2020


    Thanks for a very interesting presentation.


    • AC4: Reply to CC1, Michela De Dominicis, 05 May 2020

      Happy to hear that, thanks Sam. Michela

  • CC2: Comment on EGU2020-11619, Margaret Kadiri, 05 May 2020

    Hi Michaela. Very interesting work. In the chat, I asked how you determined the ecological cost on mobile marine species and you said you would send me your paper on how it was done. My email address is Thanks and I look forward to receiving the paper. Stay safe.

    • AC3: Reply to CC2, Michela De Dominicis, 05 May 2020

      Hi Margaret, 
      thanks for your comment.
      The live chat was very busy, so I thought it was better to send the paper separately. 

      This is about the ecological cost method: 

      I’ll send you a copy at your email address too. 

      We have another paper in preparation where we apply this methodology to the four scenarios (present, present with tidal energy extraction, future, future with tidal energy extraction) that are described in my presentation. 

      Happy to chat more about it,

      • AC6: Reply to AC3, Michela De Dominicis, 05 May 2020

        The link to the paper didn't work. Here it is:

        Sadykova, D., Scott, B.E., De Dominicis, M., Wakelin, S.L., Wolf, J. and Sadykov, A., 2020. Ecological costs of climate change on marine predator–prey population distributions by 2050. Ecology and evolution, 10(2), pp.1069-1086.

  • CC3: Comment on EGU2020-11619, Wenguo Li, 05 May 2020

    Nice presentation! But unfortunately, I miss the time for live chat. I have a question about the effect of tidal energy extraction on statification. Is the stratification enhanced or weakened by this energy extraction? It seems it is enhanced but why? Personally, I think the turbines will cause more turbulence mixing, thus will weaken the stratification.

    • AC5: Reply to CC3, Michela De Dominicis, 05 May 2020

      Thanks for your comment. 
      The increase in the turbulence mixing is probably a near field effect. We found that in the far field the on-shelf summer stratified waters are affected by the reduction in current velocities and consequent decrease in tidal mixing, which increases the strength of water stratification.  

      You can read more at this link: 


      • AC7: Reply to AC5, Michela De Dominicis, 05 May 2020

        I wanted to share the link to the paper, but it didn't work. This is the reference:

        De Dominicis, M., Wolf, J. and O'Hara Murray, R., 2018. Comparative effects of climate change and tidal stream energy extraction in a shelf sea. Journal of Geophysical Research: Oceans, 123(7), pp.5041-5067.


      • CC4: Reply to AC5, Wenguo Li, 06 May 2020

        Thank you very much for your explanation. I see. It's very instereting for me to see the impact on regional stratification. I studied the imapct of tidal turbines on hydrodynamics also with numerical model in my master study and I am thinking to continue it in my PhD. I will read your paper and maybe contact you further by email.