EGU2020-13783
https://doi.org/10.5194/egusphere-egu2020-13783
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Climate change driven massive extirpation of native species from the Israeli Mediterranean shelf

Paolo G. Albano1, Jan Steger1, Marija Bošnjak1,2, Beata Dunne1, Zara Guifarro1, Elina Turapova1, Bella Galil3, Gil Rilov4, and Martin Zuschin1
Paolo G. Albano et al.
  • 1Department of Paleontology, University of Vienna, Vienna, Austria (paolo.albano@univie.ac.at)
  • 2Croatian Natural History Museum, Zagreb, Croatia
  • 3The Steinhardt Museum of Natural History, Israel National Center for Biodiversity Studies, Tel Aviv University, Tel Aviv, Israel
  • 4National Institute of Oceanography, Israel Oceanographic and Limnological Research (ILOR), Haifa, Israel

We quantify a large-scale extirpation of native species from the Israeli Mediterranean shelf, a region strongly affected by rapidly changing environmental conditions and the introduction of non-indigenous species, based on an extensive sampling programme of mollusks on intertidal to subtidal soft and hard substrata. We reconstruct historical species richness from shelly death assemblages, quantify the time range they cover with radiocarbon dating, and compare their richness with today’s living assemblage diversity. The median native richness is 50% of the historical richness for the intertidal, but only 8% for the subtidal down to 40 m. Samples from the mesophotic zone show a much higher median of 42%, which is likely an underestimation due to sampling constraints. In contrast, non-indigenous species show assemblages matching the historical richness. Seasonality is very strong: autumn samples, after the summer heat peak, are highly impoverished in native species but enriched in non-indigenous ones. Additionally, a comparison between today’s and historical native species maximum size shows that shallow subtidal native populations are mostly non-reproductive. In contrast, non-indigenous species reach reproductive size. These results suggest that a recent large-scale change in environmental conditions is strongly favoring non-indigenous species and is the main cause behind the shallow subtidal native species decline. Such an environmental factor is likely seawater temperature that plays a greater role in the shallow subtidal than in the cooler mesophotic zone, and affects subtidal species more than intertidal ones, pre-adapted to a climatically extreme environment.

How to cite: Albano, P. G., Steger, J., Bošnjak, M., Dunne, B., Guifarro, Z., Turapova, E., Galil, B., Rilov, G., and Zuschin, M.: Climate change driven massive extirpation of native species from the Israeli Mediterranean shelf , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-13783, https://doi.org/10.5194/egusphere-egu2020-13783, 2020

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Presentation version 1 – uploaded on 04 May 2020
  • CC1: Comment on EGU2020-13783, Daniele Scarponi, 05 May 2020

    Hi Paolo and colleagues, 
    Thanks for posting the results of your research online. Just curious to know if you have time averaging estimates of native species from investigated shelly death assemblages, and if there is any correlation with water depth. 

    Best

    Daniele

    • AC2: Reply to CC1, Paolo G. Albano, 06 May 2020

      Hi Daniele,

      yes we have time-averaging data.

      On southern soft substrates, median age spanned between 207 and 1470 years. Northern soft substrates and hard substrates showed much younger median ages spanning between 18 and 56 years. Mesophotic death assemblages had a median age of 941 and 23 years on soft and hard substrates, respectively.

      TA does not correlate with depth. Here you can find an in-depth analysis of TA along a southern Israel depth transect and a comparison between shell and fish otolith TA: https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G47210.1/583376/Radiocarbon-dating-supports-bivalve-fish-age

      Let me know if you manage to access the paper, or I will send it to you by email.

      Cheers, Paolo

  • CC2: Comment on EGU2020-13783, Silvia Danise, 05 May 2020

    Hi Paolo,

    thank you for partecipating to the displays of our session.

    I have a question on your methods, how did you measure functional traits, which traits did you select for yuor analysis?

    Thanks,

    Silvia

    • AC1: Reply to CC2, Paolo G. Albano, 06 May 2020

      Hi Silvia,

      we used maximum adult body size, feeding habit, environmental position, substrate affinity and host association.

      Let me know if I can be of further assistance!

      Paolo