Ancient DNA evidence for the ecological globalization of cod fishing in medieval and post-medieval Europe.

Understanding the historical emergence and growth of long-range fisheries can provide fundamental insights into the timing of ecological impacts and the development of coastal communities during the last millennium. Whole-genome sequencing approaches can improve such understanding by determining the origin of archaeological fish specimens that may have been obtained from historic trade or distant water. Here, we used genome-wide data to individually infer the biological source of 37 ancient Atlantic cod specimens (ca 1050-1950 CE) from England and Spain. Our findings provide novel genetic evidence that eleventh- to twelfth-century specimens from London were predominantly obtained from nearby populations, while thirteenth- to fourteenth-century specimens were derived from distant sources. Our results further suggest that Icelandic cod was indeed exported to London earlier than previously reported. Our observations confirm the chronology and geography of the trans-Atlantic cod trade from Newfoundland to Spain starting by the early sixteenth century. Our findings demonstrate the utility of whole-genome sequencing and ancient DNA approaches to describe the globalization of marine fisheries and increase our understanding regarding the extent of the North Atlantic fish trade and long-range fisheries in medieval and early modern times.

Contribution to Mediterranean medieval dietary studies: Stable carbon and nitrogen isotope data of marine and catadromous fish from Provence (9th-14th CE).

Whilst marine resources are one of the pillars of the Mediterranean diet, their mode of acquisition and subsequent consumption by medieval populations in southern France are still not well known. Throughout Europe, bioarchaeological techniques, however, are beginning to reveal hitherto unknown aspects of these practices both dating to the medieval period as well as other periods of history and prehistory. This study involved the stable isotope analysis of five marine and catadromous taxa from three medieval sites in Provence, France: "rue Frédéric Mistral" at Fos-sur-Mer, "le Château" at Hyères and "Couvent des Dominicaines - Parking/Collège Mignet" at Aix-en-Provence. In total, 127 specimens, including Anguilla anguilla, Dicentrarchus labrax, Sparus aurata, Diplodus sargus and Mugilidae were subjected to carbon and nitrogen stable isotope analysis. The study provides a crucial and unprecedented point of reference of the carbon and nitrogen isotopic variability of one of the main dietary resources in the Mediterranean world, fish.