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Drivers of Pontocaspian biodiversity RIse and DEmise

Periodic Reporting for period 2 - PRIDE (Drivers of Pontocaspian biodiversity RIse and DEmise)

Reporting period: 2017-03-01 to 2019-02-28

Discovering drivers of past and modern biodiversity crises in the Black Sea – Caspian Sea region: integrating climate, geosciences and biological sciences across borders.

Crisis, what crisis? How can we talk about a biodiversity crisis if we do not know how bad the deterioration actually is? Because we do not know the species well. Or the areas involved are remotely accessible. Or expertise fragmented. And even if we know the species and the areas, and we do have enough experts and good facilities to investigate, how do we know we are not merely looking into natural variability, as biodiversity has been fluctuating through time?

In the Black Sea – Caspian Sea region a unique biota evolved in partial isolation during the past few million years adapted to the fluctuating salinity regimes in these basins. These aquatic taxa include crustacean, mollusk, and fish species like the sturgeon, but also the Caspian seal. As a result of a variety of anthropogenic pressures these so-called Pontocaspian biota currently undergo severe change. Understanding the natural variability of biota through time, including their capacity to withstand periods of adverse conditions (their resilience) is required to appreciate the significance of the changes of today. The evolution of the Pontocaspian biota is intimately linked with the evolution of the lake basins and adjacent rivers in the Black Sea – Caspian Sea region.

The overall aims are to identify how lakes and seas in the Pontocaspian region evolved and how the unique species responded to environmental change in the past in order to understand and mitigate the current biodiversity crisis. We use climate models and geology to understand drivers of lake basin evolution. At the same time, we look at the pressures that nowadays drive deterioration of the Pontocaspian faunas and floras. We predict future impacts on biodiversity under a range of climate change, invasive and environmental scenarios. Together with stakeholders from the Pontocaspian region we aim to increase understanding of the value of these unique species, to raise regional awareness and to seek follow-up actions for conservation.

Fifteen early stage researchers together with about 40 scientists from 25 institutes both in western Europe and the Black Sea - Caspian Sea region engaged in 2015 on a search to understand (and mitigate) the rise and demise of Pontocaspian biota. We established a network that will continue to collaborate to deal with the drivers and consequences of the Pontocaspian biodiversity crisis and seek solutions.
In work package 1, geologists and climatologists jointly reconstructed drivers of lake basin evolution and found that the combination of climate settings and tectonic configuration determined lake levels and connectivity in the past, as well as the preservation of a wonderful geological archive. Geochemical and palynological proxies helped us to estimate the relevance of rivers, including now vanished giants such as the Amu Darya/Uzboy that previously was as important for the Caspian Sea as the Volga is today.

In work package 2 geologists, paleontologists and molecular biologists were able to determine the shifting centers of evolution through time and environmental conditions that drove evolution of the unique Pontocaspian biota. Repeated establishment of marine conditions in the Black Sea during interglacials in the past half million years as well as episodic Caspian overflows into the Black Sea have been a major driver behind the development of Pontocaspian biota in that basin. The integrated approach has shown us that the current demise is extremely rapid and differs from natural variability by the speed and nature of driving processes.

In Work package 3 the severity of the Pontocaspian biodiversity crisis became clear by the great efforts it took us to collect only a fraction of species alive that were present around 100 years ago during the various fieldworks and expeditions. We found that invasive species as well as pollution are the main drivers of deterioration today. The awareness of the unique character of Pontocaspian biota in the region is low, both by the general public and the conservation stakeholders. Yet, inventories of stakeholders in the Black Sea region did show us that conditions for effective conservation are in place in parts of the region.
During the PRIDE program we developed a very intense training environment for 15 young researchers (ESRs) as well as for all scientists and participants.

The cross-disciplinary training improved the ESR career perspectives. Our progress resulted from crossing borders, between disciplines, lake basins and the different countries. We are sure that we can only understand and address the Pontocaspian biodiversity crises if we thoroughly integrate scientific understandings across disciplines.

By actively engaging with institutes and researchers from the Pontocaspian region through our partners, we established a strong regional network. This network spans from West to Eastern Europe and beyond, including Turkey, Russia, Ukraine, Kazakhstan, Georgia, Armenia and Azerbaijan. This (1) makes our projects and results more widely and better supported, (2) gave us the possibility to reach out to the stakeholders in the region to address conservation of endemic species (3) will lead to more follow up projects and programs and (4) will hence increase the future career prospects of our ESRs, (5) will let all involved benefit from this network now and in the future.

Our research led to follow up recommendations to the International Union for Conservation of Nature and Natural Resources (IUCN) for conservation of mollusc species and mitigation of threats.

In this program some ESRs got the opportunity to work with the newest climate models on a supercomputer, bringing new knowledge about different climate change and processes in the Pontocaspian region which have not been studied yet with state-of-the-art climate models. They predict that the Black and Caspian Sea area will rise in temperature of between 3 and 6 degrees in the year 2100 under different future climate scenarios. And they predict that the Caspian Sea level will drop 9 to 18 meters by the year 2100. These are new insights. This drop will have a huge impact on biodiversity, humanity and economy in the region.

Data and associated software produced in PRIDE are accessible after publication of the results in peer reviewed journals, and will be made accessible through the PRIDE website, PC-TAX, PC-IS and general systems like GBIF, NCBI's GenBank, Pangea and the IUCN Red list.

The project resulted in 1 PhD defended, and 12 planned in the near future. 5 ESRs already found high level jobs, for example with the Baltic Marine Environment Protection Commission, and the Natural Environment Research Council in the UK, a Dutch Marine Consultancy company. We are happy to see that they are in areas of research and protection of the natural environment.