Post by Daniela Leal

New paper is out! Here is the second half of my MSc thesis, which I conducted alongside Maria Bas López, Konstantina Agiadi and Marta Coll Monton at the Institut de Ciències del Mar (CSIC) in Barcelona, Spain. In this study, we used paleoecological, historical, and geological data from a systematic review of two species of molluscs and two species of fish in the Mediterranean Sea, spanning a period from 130,000 years ago to the Industrial Revolution. We sought to understand the impacts of anthropogenic and climatic changes during this period on this biodiversity hotspot, which has undergone many changes over time. If you’d like to take a closer look at what we discovered and what this means in terms of long-term perspectives of the state of the ecosystem over time, feel free to check it out below ⬇️ Abstract Historical baselines are essential for evaluating the cumulative impacts on modern marine ecosystems, particularly in regions such as the Mediterranean, where human activities have been intensive for millennia, and climate change is accelerating. However, quantitative evidence of historical impacts remains fragmented. In this study, we investigate changes in the presence, abundance and body size (BS) of the Atlantic bluefin tuna (Thunnus thynnus), gilthead sea bream (Sparus aurata), banded-dye murex (Hexaplex trunculus) and turbinate monodont (Phorcus turbinatus) across the Mediterranean Sea from 130 000 years Before Present until the Industrial Revolution (1850 AD), using geological, archaeological, and historical records. Our results reveal significant temporal shifts in the abundance and BS of the banded-dye murex, Atlantic bluefin tuna, and gilthead sea bream. Environmental factors, particularly seawater temperature, were the primary drivers of abundance and size in Atlantic bluefin tuna in the past. Human activities, especially exploitation, influenced the abundance of banded-dye murex and Atlantic bluefin tuna, as well as the BS of gilthead sea bream. These findings underscore the importance of integrating long-term ecological data to understand better the interplay between climate, human pressures, and ecosystem dynamics.