Late Miocene Mediterranean Marine Ecosystem Crisis

The period between 11.63 and 5.33 million years ago (Late Miocene) was a pivotal time for the Mediterranean Sea, because paleogeographic reconfigurations were rapidly changing it shape, extent and connections to the global ocean, while global climate was cooling. The culmination of these phenomena was the Messinian Salinity Crisis, during which kilometer-thick beds of salt were deposited on the Mediterranean sea floor, implying extreme environmental conditions for marine organisms at the time leading up to and during the event. Although evidence of this ecological crisis is abundant in the fossil record, its ultimate impact on the biodiversity and structure of the Mediterranean ecosystem has never been studied systematically before. In this project, we investigate the ecosystem functioning before and after the Crisis. Functional diversity refers to the different roles species play within an ecosystem. For example, two communities with the same number of species may be quite different, if they include species with vastly different lifestyles, sizes, feeding habits etc. These qualities of the species are called traits, and they determine their function within the ecosystem. By grouping species in terms of their traits, instead of their taxonomic identity, we gain knowledge on if and how the Mediterranean ecosystem function changed due to the Messinian Salinity Crisis. Furthermore, ecosystem models allow us to visualize and study the flow of energy through an ecosystem, and investigate the significance of environmental changes on its functioning. During an ecological crisis, such as the one studied here, if one group disappears, its prey may increase in numbers uncontrollably, whereas its predator is in danger of dying out due to lack of food, and such changes have cascading impacts on the entire food web. We use here different m odels to explore multiple what if scenarios and compare them to the fossil record to answer the question: What was the true impact of the Messinian Salinity Crisis on the marine biota? This project is led by Dr. Konstantina Agiadi (University of Vienna, Austria), in collaboration with Dr. Marta Coll (Instituto de Ciencias del Mar, CSIC, Barcelona, Spain), Dr. Jérôme Pierre Alexander Pinti (University of Delaware, USA) and Niklas Hohmann (University of Warsaw, Poland).