SEACHANGE, História da exploração de pequenos peixes pelágicos na Península Ibérica e Mediterrâneo usando paleogenómica: implicação para a definição de stocks e de efectivos populacionais ancestrais

The main aim of this research project is to uncover the population dynamics of the European sardine (Sardina pilchardus), the Atlantic chub mackerel (Scomber colias) and the Atlantic horse mackerel (Trachurus trachurus), throughout their distribution range, exploring the long-term history of overfishing in the Northeast Atlantic, in order to evaluate biodiversity levels through time and ultimately assess baseline data on pre-exploitation population levels applicable to species conservation and management proposals. Promoting both sustainable fisheries and biodiversity conservation. This will be done using a multidisciplinary, ground-breaking and innovative approach. We will use state of the art aDNA techniques to recover DNA data from samples that pre-date periods of intensive fishing, mostly recovered from Roman archaeological fish salting plants, and compare those results to the ones obtained for current populations (post exploitation). The great advantage of using these three species (sardines, Atlantic horse and chub mackerel species) is that they are easy to find in the bottom of fish salting vats rendering all the samples contemporaneous, enabling us to treat them as a population, and giving us a window into a fixed point in history. A practical point of choosing these three species is that they are difficult to morphologically identify based on crushed remains. We hypothesize that genetic diversity was lost over time in response to the unsustainable fishing practices of the last century, so assessing how much diversity was lost in the past millennium and establishing a baseline for these species before commercial fishing started will give us a more accurate perspective of pristine populations. Results from this project will serve to inform relevant scientific advisory boards and authorities in issues related to overfishing, such as the International Council for the Exploration of the Sea (ICES) and the national Instituto Português do Mar e da Atmosfera (IPMA), that can use these results in a hindcasting to forecast strategy to improve our understanding of fisheries and help predict future population fluctuations as well as in the definition of fishing effort and stock management in the different Food and Agricultural Organization (FAO) fishing areas. Overall, the analysis of fish remains is a multidisciplinary approach that combines archaeology, anthropology, biology, and environmental science to piece together the complex relationship between past human societies and the vast ocean ecosystems. This project will also give us a better picture of past societies and its customs, diet and resource exploitation. The inherent risk underscores the ground breaking nature of this project.