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van der Jagt, I.

Publications and source records attributed to van der Jagt, I..

3 recordsLinked to original sources

2000-year fish bone record reveals transition to commercial fisheries during climatic change

Animal bones from archaeological contexts can reveal the interplay between past environments and human societies. Resource acquisition shaped many aspects of past societies and influenced the development of trade networks and migration. Fish have been a cornerstone of human subsistence for millennia, yet the rise of commercial fishing and trade was complex. Here, we synthesised a database of [~]1.9 million zooarchaeological fish records spanning 2000 years across Europe. Using machine-learning of catch compositions alongside fish thermal tolerances, we show that fisheries became less local over time, with homogenisation coinciding with Little Ice Age-associated cooling, a period of documented resource scarcity, concurring with growing trade. Moreover, increased proportions of marine taxa and more specialist marine fisheries were observed in the preceding Medieval Climate Anomaly, to sustain concurrent urban and population growth. Enhanced use of marine protein buffered food insecurity, whilst signalling the transition from localised to trans-regional trade networks.

ecology↗

The Once and Future Fish: 1300 years of Atlantic herring population structure and demography revealed through ancient DNA and mixed-stock analysis

Atlantic herring populations have been the target of highly profitable coastal and pelagic fisheries in northern Europe for well over a thousand years. Their complex and intermingled population dynamics have sparked extensive debate over the impacts of historical overfishing and have complicated their sustainable management today. Recently developed tools - including diagnostic SNP panels for mixed-stock analysis - aim to improve population assignment for fisheries management, however, the biological relevance of such tools over long periods of time remains unknown. Here, we demonstrate the millennium-long applicability of diagnostic SNP panels and identify population perturbations associated with increasing exploitation pressure and climate change by analyzing whole genome data from modern and ancient herring specimens. We find that herring demographic cycles were likely within healthy ecosystem boundaries until the dramatic disruption of these cycles in the 20th century. We find only autumn-spawning herring in our archaeological remains spanning 900 years from 8 sites across Europe, supporting observations that the numerical dominance of specific spawning populations can demographically outcompete other herring types. We also obtain pre-archival aDNA evidence for the famous, cyclical "Bohuslan periods," during which mass quantities of North Sea autumn-spawning herring congregated in the Skagerrak. Finally, the long-term applicability of diagnostic SNP panels underscores their highly cost-effective application for the genetic monitoring of herring stocks. Our results highlight the utility of ancient DNA and genomic analysis to obtain historical and natural insights in herring ecology and population dynamics with relevance for sustainable fisheries management.

ecology↗

The preservation of ancient DNA in archaeological fish bone

The field of ancient DNA is taxonomically dominated by studies focusing on mammals. This taxonomic bias limits our understanding of endogenous DNA preservation for vertebrate taxa with different bone physiology, such as teleost fish. In contrast to most mammalian bone, teleost bone is typically brittle, porous, lightweight and is characterized by a lack of bone remodeling during growth. Using high-throughput shotgun sequencing, we here investigate the preservation of DNA in a range of different bone elements from over 200 archaeological Atlantic cod (Gadus morhua) specimens from 38 sites in northern Europe, dating up to 8000 years before present. We observe that the majority of archaeological sites (79%) yield endogenous DNA, with 40% of sites providing samples that contain high levels (> 20%). Library preparation success and levels of endogenous DNA depend mainly on excavation site and pre-extraction laboratory treatment. The use of pre-extraction treatments lowers the rate of library success, although -- if successful -- the fraction of endogenous DNA can be improved by several orders of magnitude. This trade-off between library preparation success and levels of endogenous DNA allows for alternative extraction strategies depending on the requirements of down-stream analyses and research questions. Finally, we find that -- in contrast to mammalian bones -- different fish bone elements yield similar levels of endogenous DNA. Our results highlight the overall suitability of archaeological fish bone as a source for ancient DNA and provide novel evidence for a possible role of bone remodeling in the preservation of endogenous DNA across different classes of vertebrates.

evolutionary biology↗