Research Output

Publications

Publications produced by the SeaChanges early-stage researchers in relation to their projects.

Exploitation shifted trophic ecology and habitat preferences of Mediterranean and Black Sea bluefin tuna over centuries

Adam J. Andrews, Christophe Pampoulie, Antonio Di Natale, Piero Addis, Darío Bernal-Casasola, Veronica Aniceti, Gabriele Carenti, Verónica Gómez-Fernández, Valerie Chosson, Alice Ughi, Matt Von Tersch, Maria Fontanals-Coll, Elisabetta Cilli, Vedat Onar, Fausto Tinti, Michelle Alexander

https://doi.org/10.1111/faf.12785

Abstract

During recent decades, the health of ocean ecosystems and fish populations has been threatened by overexploitation, pollution and anthropogenic-driven climate change. Due to a lack of long-term ecological data, we have a poor grasp of the true impact on the diet and habitat use of fishes. This information is vital if we are to recover depleted fish populations and predict their future dynamics. Here, we trace the long-term diet and habitat use of Atlantic bluefin tuna (BFT), Thunnus thynnus, a species that has had one of the longest and most intense exploitation histories, owing to its tremendous cultural and economic importance. Using carbon, nitrogen and sulphur stable isotope analyses of modern and ancient BFT including 98 archaeological and archival bones from 11 Mediterranean locations ca. 1st century to 1941 CE, we infer a shift to increased pelagic foraging around the 16th century in Mediterranean BFT. This likely reflects the early anthropogenic exploitation of inshore coastal ecosystems, as attested by historical literature sources. Further, we reveal that BFT which migrated to the Black Sea–and that disappeared during a period of intense exploitation and ecosystem changes in the 1980s–represented a unique component, isotopically distinct from BFT of NE Atlantic and Mediterranean locations. These data suggest that anthropogenic activities had the ability to alter the diet and habitat use of fishes in conditions prior to those of recent decades. Consequently, long-term data provide novel perspectives on when marine ecosystem modification began and the responses of marine populations, with which to guide conservation policy.

Published online: 10 August 2023

Threatened North African seagrass meadows have supported green turtle populations for millennia

Willemien de Kock, Meaghan Mackie, Max Ramsøe, Morten E. Allentoft, Annette C. Broderick, Julia C. Haywood, Brendan J. Godley, Robin T. E. Snape, Phil J. Bradshaw, Hermann Genz, Matthew von Tersch, Michael W. Dee, Per J. Palsbøll, Michelle Alexander, Alberto J. Taurozzi, and Canan Çakırlar

https://doi.org/10.1073/pnas.2220747120

Abstract

“Protect and restore ecosystems and biodiversity” is the second official aim of the current UN Ocean Decade (2021 to 2030) calling for the identification and protection of critical marine habitats. However, data to inform policy are often lacking altogether or confined to recent times, preventing the establishment of long-term baselines. The unique insights gained from combining bioarchaeology (palaeoproteomics, stable isotope analysis) with contemporary data (from satellite tracking) identified habitats which sea turtles have been using in the Eastern Mediterranean over five millennia. Specifically, our analysis of archaeological green turtle (Chelonia mydas) bones revealed that they likely foraged on the same North African seagrass meadows as their modern-day counterparts. Here, millennia-long foraging habitat fidelity has been directly demonstrated, highlighting the significance (and long-term dividends) of protecting these critical coastal habitats that are especially vulnerable to global warming. We highlight the potential for historical ecology to inform policy in safeguarding critical marine habitats.

Published online: 17 July 2023

Prehistoric and historic exploitation of marine mammals in the Black Sea

Magie Aiken, Elena Gladilina, Canan Çakırlar, Serhii Telizhenko, Youri van den Hurk, Luminita Bejenaru, Morten Tange Olsen, Pavel Gol'din

https://doi.org/10.1016/j.quascirev.2023.108210

Abstract

The recent exploitation of marine species is relatively well documented and understood in terms of impacts on species abundance, distribution, and resource use. In contrast, ancient exploitation of marine mammals remains poorly documented; in part, because a detailed meta-analysis of their presence in the zooarchaeological record is lacking. This is true in the Black Sea, where cetaceans are reported in the zooarchaeological record but have not yet been studied comprehensively. Here, we synthesize all available published and unpublished zooarchaeological data from 27 sites around the Black Sea, dating from the Mesolithic and Neolithic periods (6500-6000 BCE) to the Medieval period (641–1475 CE), to document the extent and nature of the exploitation of the Black Sea cetacean species. The results suggest that cetacean exploitation was practised continuously in the Black Sea over a period of 8500 years from the Neolithic through to the Medieval period. This suggests a much longer history of marine mammal exploitation in the Black Sea than previously understood, pushing back the timeline of human impacts on the Black Sea marine fauna.

Published online: 13 July 2023

Grouping groupers in the Mediterranean: ecological baselines revealed by ancient proteins

Rachel M. Winter, Willemien de Kock, Meaghan Mackie, Max Ramsøe, Elena Desiderà, Matthew Collins, Paolo Guidetti, Samantha Presslee, Marta Munoz Alegre, Tarek Oueslati, Arturo Morales Muniz, Dimitris Michailidis, Youri van den Hurk, Alberto J. Taurozzi, Canan Çakirlar

https://doi.org/10.22541/au.168718339.91279944/v1

Abstract

Marine historical ecology provides a means to establish baselines to inform current fisheries management. Groupers (Epinephelidae) are key species for fisheries in the Mediterranean which have been heavily overfished. Species abundance and distribution prior to the 20th century in the Mediterranean remains poorly known. To reconstruct the past biogeography of Mediterranean groupers, we investigated if Zooarchaeology by Mass Spectrometry (ZooMS) can be used for identifying intra-genus grouper bones to species level. We discovered 22 novel, species-specific ZooMS biomarkers for groupers. Applying these biomarkers to a northeastern Mediterranean archaeological site demonstrated 4000 years of regional Epinephelus aeneus dominance and resiliency through millennia of fishing pressures, habitat degradation, and climatic changes. Combining ZooMS identifications with catch size reconstructions revealed the Epinephelus aeneus capacity for growing 30 cm larger than hitherto documented. Our results provide ecological baselines for a key Mediterranean fishery which could be leveraged to define and assess conservation targets.

Preprint: 19 June 2023

Isotopic life-history signatures are retained in modern and ancient Atlantic bluefin tuna vertebrae

Adam J. Andrews, David Orton, Vedat Onar, Piero Addis, Fausto Tinti, Michelle Alexander

https://doi.org/10.1111/jfb.15417

Abstract

Isotopic, tagging and diet studies of modern-day teleosts lacked the ability to contextualise life-history and trophic dynamics with a historical perspective, when exploitation rates were lower and climatic conditions differed. Isotopic analysis of vertebrae, the most plentiful hard-part in archaeological and museum collections, can potentially fill this data-gap. Chemical signatures of habitat and diet use during growth are retained by vertebrae during bone formation. Nonetheless, to fulfil their potential to reveal life-history and trophic dynamics, we need a better understanding of the time frame recorded by vertebrae, currently lacking due to a poor understanding of fish bone remodelling. To address this issue, the authors serially-sectioned four vertebral centra of the highly migratory Atlantic bluefin tuna (Thunnus thynnus; BFT) captured off Sardinia (Italy) and analysed their isotopic composition. They show how carbon (δ13C), nitrogen (δ15N) and sulphur (δ34S) isotope values can vary significantly across BFT vertebrae growth-axes, revealing patterning in dietary life histories. Further, they find that similar patterns are revealed through incremental isotopic analysis of inner and outer vertebrae centra samples from 13 archaeological BFT vertebrae dating between the 9th and 13th centuries CE. The results indicate that multi-year foraging signatures are retained in vertebrae and allow for the study of life histories in both modern and paleo-environments. These novel methods can be extended across teleost taxa owing to their potential to inform management and conservation on how teleost trophic dynamics change over time and what their long-term environmental, ecological and anthropological drivers are.

Published Online: 26 April 2023

Rapid collagen peptide mass fingerprinting as a tool to authenticate Pleuronectiformes in the food industry

Katrien Dierickx, Sam Presslee, Virginia L. Harvey

https://doi.org/10.1016/j.foodcont.2023.109680

Abstract

Reliable species identification of specimens in the food chain is crucial for detecting mislabelling fraud. While visual identification, DNA-analyses, and proteomic approaches have been used in the past, this research provides an alternative proteomic technique that has been trialled here to identify tissue samples from species within the order Pleuronectiformes (flatfish). Previously, archaeological research has used peptide mass fingerprinting to identify fish remains to species by extracting collagen Type I preserved in bones. As this type of collagen can also be found in the fins, skin and muscle of fishes (types of tissue that can be found throughout the food chain), collagen peptide mass fingerprinting has been applied here to identify modern fish specimens to species. In this study, MALDI-ToF MS peptide fingerprints are obtained from enzymatic digestion of collagen Type I from fin (or skin if fin was not available) and muscle tissues from six specimens of Pleuronectiformes. Using the already available diagnostic collagen peptide biomarkers for flatfish, all six specimens could be identified to the correct species for each of the tissue types. We recommend using this rapid approach for future screenings of modern flatfish in the food chain to detect mislabelling fraud, and also in more general applications of modern ecological studies of this order. It is likely that the methods can be applied to other Actinopterygian fishes.

Published Online: 14 February 2023

Catch of the day: abundance and size data of groupers (Epinephelidae) and combers (Serranidae) from Middle to Late Holocene Levantine archaeological contexts

Rachel Winter, Elena Desidera, Paolo Guidetti, Shyama Vermeersch, Nazli Demirel, Canan Çakırlar

https://doi.org/10.1080/15564894.2022.2138643

Abstract

Groupers (Epinephelidae) are ecologically, commercially, and culturally important carnivorous fishes found throughout the world’s tropical, subtropical, and temperate coastal marine waters. Due to various life history traits (e.g., late maturity, sequential hermaphroditism) and behavior (e.g., sedentary, small home ranges) groupers are susceptible to overfishing, including small-scale and recreational fishing (especially spearfishing), and their populations are declining worldwide. The eastern Mediterranean coast, home to some of the world’s longest continuously occupied urban settlements, hosts important but declining grouper populations. This paper investigates how grouper and comber (fishes in the Serranidae family with similar ecology and osteomorphology, but smaller in size) abundance and catch size changed in the eastern Mediterranean from the Middle to Late Holocene, coinciding with early coastal urbanization, by estimating their relative frequency and reconstructing their size. Size reconstructions have been done from a large sample of bones (Number of Identified Specimens = 1851) recovered from Kinet Höyük in Turkey, and Tell Fadous-Kfarabida and Tell el-Burak in Lebanon, habitation sites along the Levantine coast. Our results imply that groupers in the past reached >100 cm more often than is observed today in areas open to commercial fishing. Furthermore, the apparent lack of large groupers by the Hellenistic Period at Kinet Höyük suggests fishing efforts were intense enough to have either had an appreciable effect on the size structure of local grouper populations or brought about a behavioral change to the fishes of moving to deeper waters.

Published Online: 23 December 2022  

Population dynamics of Baltic herring since the Viking Age revealed by ancient DNA and genomics

Lane M. Atmore, Lourdes Martínez-García, Daniel Makowiecki, Carl André, Lembi Lõugas, James H. Barrett, Bastiaan Star

https://doi.org/10.1073/pnas.2208703119

Abstract

The world’s oceans are currently facing major stressors in the form of overexploitation and anthropogenic climate change. The Baltic Sea was home to the first “industrial” fishery ∼800 y ago targeting the Baltic herring, a species that is still economically and culturally important today. Yet, the early origins of marine industries and the long-term ecological consequences of historical and contemporary fisheries remain debated. Here, we study long-term population dynamics of Baltic herring to evaluate the past impacts of humans on the marine environment. We combine modern whole-genome data with ancient DNA (aDNA) to identify the earliest-known long-distance herring trade in the region, illustrating that extensive fish trade began during the Viking Age. We further resolve population structure within the Baltic and observe demographic independence for four local herring stocks over at least 200 generations. It has been suggested that overfishing at Øresund in the 16th century resulted in a demographic shift from autumn-spawning to spring-spawning herring dominance in the Baltic. We show that while the Øresund fishery had a negative impact on the western Baltic herring stock, the demographic shift to spring-spawning dominance did not occur until the 20th century. Instead, demographic reconstructions reveal population trajectories consistent with expected impacts of environmental change and historical reports on shifting fishing targets over time. This study illustrates the joint impact of climate change and human exploitation on marine species as well as the role historical ecology can play in conservation and management policies.

Published Online: 25 October 2022  

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

Lourdes Martínez-García, Giada Ferrari, Angélica Cuevas, Lane M. Atmore, Begoña López-Arias, Mark Culling, Laura Llorente-Rodríguez, Arturo Morales-Muñiz, Eufrasia Roselló-Izquierdo, Juan Antonio Quirós, Ricard Marlasca-Martín, Bernd Hänfling, William F. Hutchinson, Kjetill S. Jakobsen, Sissel Jentoft, David Orton, Bastiaan Star and James H. Barrett

https://doi.org/10.1098/rspb.2022.1107

Abstract

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.

Published Online: 19 October 2022  

Peptide mass fingerprinting of preserved collagen in archaeological fish bones for the identification of flatfish in European waters

Katrien Dierickx, Samantha Presslee, Richard Hagan, Tarek Oueslati, Jennifer Harland, Jessica Hendy, David Orton, Michelle Alexander and Virginia L. Harvey

https://doi.org/10.1098/rsos.220149

Abstract

Bones of Pleuronectiformes (flatfish) are often not identified to species due to the lack of diagnostic features on bones that allow adequate distinction between taxa. This hinders in-depth understanding of archaeological fish assemblages and particularly flatfish fisheries throughout history. This is especially true for the North Sea region, where several commercially significant species have been exploited for centuries, yet their archaeological remains continue to be understudied. In this research, eight peptide biomarkers for 18 different species of Pleuronectiformes from European waters are described using MALDI-TOF MS and liquid chromatography tandem mass spectrometry data obtained from modern reference specimens. Bone samples (n = 202) from three archaeological sites in the UK and France dating to the medieval period (ca seventh–sixteenth century CE) were analysed using zooarchaeology by mass spectrometry (ZooMS). Of the 201 that produced good quality spectra, 196 were identified as flatfish species, revealing a switch in targeted species through time and indicating that ZooMS offers a more reliable and informative approach for species identification than osteological methods alone. We recommend this approach for future studies of archaeological flatfish remains as the precise species uncovered from a site can tell much about the origin of the fish, where people fished and whether they traded between regions.


Published Online: 27 July 2022  

Ancient DNA reveals a southern presence of the Northeast Arctic cod during the Holocene

Lourdes Martínez-García, Giada Ferrari, Anne Karin Hufthammer, Kjetill S. Jakobsen, Sissel Jentoft, James H. Barrett and Bastiaan Star

https://doi.org/10.1098/rsbl.2022.0021

Abstract

Climate change has been implicated in an increased number of distributional shifts of marine species during the last century. Nonetheless, it is unclear whether earlier climatic fluctuations had similar impacts. We use ancient DNA to investigate the long-term spawning distribution of the Northeast Arctic cod (skrei) which performs yearly migrations from the Barents Sea towards spawning grounds along the Norwegian coast. The distribution of these spawning grounds has shifted northwards during the last century, which is thought to be associated with food availability and warming temperatures. We genetically identify skrei specimens from Ruskeneset in west Norway, an archaeological site located south of their current spawning range. Remarkably, 14C analyses date these specimens to the late Holocene, when temperatures were warmer than present-day conditions. Our results either suggest that temperature is not the only driver influencing the spawning distribution of Atlantic cod, or could be indicative of uncertainty in palaeoclimate reconstructions in this region. Regardless, our findings highlight the utility of aDNA to reconstruct the historical distribution of economically important fish populations and reveal the complexity of long-term ecological interactions in the marine environment.


Published Online: 04 May 2022 

Length estimation of Atlantic bluefin tuna (Thunnus thynnus) using vertebrae

Adam J. Andrews, Dimitra Mylona, Lucia Rivera-Charún, Rachel Winter, Vedat Onar, Abu B. Siddiq, Fausto Tinti, Arturo Morales-Muniz

https://doi.org/10.1002/oa.3092

Abstract

Atlantic bluefin tuna (Thunnus thynnus; BFT) is a large (up to 3.3 m in length) pelagic predator which has been exploited throughout the eastern Atlantic and Mediterranean since prehistoric times, as attested by its archeological remains. One key insight derivable from these remains is body size, which can indicate past fishing abilities, the impact of fishing, and past migration behavior. Despite this, there exists no reliable method to estimate the size of BFT found in archeological sites. Here, 13 modern Thunnus spp. skeletons were studied to provide power regression equations that estimate body length from vertebra dimensions. In modern specimens, the majority of BFT vertebrae can be differentiated by their morphological features, and thus, individual regression equations can be applied for each rank (position in vertebral column). In an archeological context, poor preservation may limit one's ability to identify rank; hence, “types” of vertebrae were defined, which enable length estimates when rank cannot be determined. At least one vertebra dimension, height, width, or length correlated highly with body length when vertebrae were ranked (R2 > 0.97) or identified to types (R2 > 0.98). Whether using rank or type, length estimates appear accurate to approximately ±10%. Finally, the method was applied to a sample of Roman-era BFT vertebrae to demonstrate its potential. It is acknowledged that further studies with larger sample sizes would provide more precision in BFT length estimates.

Published Online: 23 January 2022 

Exploitation history of Atlantic bluefin tuna in the eastern Atlantic and Mediterranean—insights from ancient bones 

Adam J Andrews, Antonio Di Natale, Darío Bernal-Casasola, Veronica Aniceti, Vedat Onar, Tarek Oueslati, Tatiana Theodropoulou, Arturo Morales-Muñiz, Elisabetta Cilli, Fausto Tinti 

https://doi.org/10.1093/icesjms/fsab261

Abstract

Overexploitation has directly, negatively affected marine fish populations in the past half-century, modifying not only their abundance but their behaviour and life-history traits. The recovery and resilience of such populations is dependent upon their exploitation history, which often extends back millennia. Hence, data on when exploitation intensified and how populations were composed in historical periods, have the potential to reveal long-term population dynamics and provide context on the baselines currently used in fisheries management and conservation. Here, we setup a framework for investigations on the exploitation history of Atlantic bluefin tuna (Thunnus thynnus; BFT) in the eastern Atlantic and Mediterranean by collating records of their zooarchaeological remains and critically reviewing these alongside the literature. Then, we outline how novel multidisciplinary applications on BFT remains may be used to document long-term population dynamics. Our review of literature provides clear evidence of BFT overexploitation during the mid-20th century CE. Furthermore, a strong case could be made that the intensification of BFT exploitation extends back further to at least the 19th century CE, if not the 13th–16th century CE, in the eastern Atlantic and Mediterranean. However, a host of archaeological evidence would suggest that BFT exploitation may have been intensive since antiquity. Altogether, this indicates that by the currently used management baselines of the 1970s,  population abundance and complexity was already likely to have declined from historical levels, and we identify how biomolecular and morphometric analyses of BFT remains have the potential to further investigate this.


Published Online: 18 January 2022  

Shifting Baselines to Thresholds: Reframing Exploitation in the Marine Environment

Lane M. Atmore, Magie Aiken and Fabricio Furni

https://doi.org/10.3389/fmars.2021.742188

Abstract

Current research on anthropogenic impacts on marine ecosystems often relies on the concept of a “baseline,” which aims to describe ecosystems prior to human contact. Recent research is increasingly showing that humans have been involved in marine ecosystems for much longer than previously understood. We propose a theoretical framework oriented around a system of “thresholds” referring to system-wide changes in human culture, ecosystem dynamics, and molecular evolution. The concept of the threshold allows conceptual space to account for the fluid nature of ecosystems throughout time while providing a critical framework for understanding drivers of ecosystem change. We highlight practical research approaches for exploring thresholds in the past and provide key insights for future adaptation to a changing world. To ensure ecological and societal goals for the future are met, it is critical that research efforts are contextualized into a framework that incorporates human society as integral to ecology and evolution.

Published Online: 19 November 2021  

An accurate assignment test for extremely low-coverage whole-genome sequence data

Giada Ferrari, Lane M. Atmore, Sissel Jentoft, Kjetill S. Jakobsen, Daniel Makowiecki, James H. Barrett, Bastiaan Star

https://doi.org/10.1111/1755-0998.13551

Abstract

Genomic assignment tests can provide important diagnostic biological characteristics, such as population of origin or ecotype. Yet, assignment tests often rely on moderate- to high-coverage sequence data that can be difficult to obtain for fields such as molecular ecology and ancient DNA. We have developed a novel approach that efficiently assigns biologically relevant information (i.e., population identity or structural variants such as inversions) in extremely low-coverage sequence data. First, we generate databases from existing reference data using a subset of diagnostic single nucleotide polymorphisms (SNPs) associated with a biological characteristic. Low-coverage alignment files are subsequently compared to these databases to ascertain allelic state, yielding a joint probability for each association. To assess the efficacy of this approach, we assigned haplotypes and population identity in Heliconius butterflies, Atlantic herring, and Atlantic cod using chromosomal inversion sites and whole-genome data. We scored both modern and ancient specimens, including the first whole-genome sequence data recovered from ancient Atlantic herring bones. The method accurately assigns biological characteristics, including population membership, using extremely low-coverage data (as low as 0.0001x) based on genome-wide SNPs. This approach will therefore increase the number of samples in evolutionary, ecological and archaeological research for which relevant biological information can be obtained.

Published Online: 14 November 2021

Ancient DNA SNP-panel data suggests stability in bluefin tuna genetic diversity despite centuries of fluctuating catches in the eastern Atlantic and Mediterranean

Adam J. Andrews, Gregory N. Puncher, Darío Bernal-Casasola, Antonio Di Natale, Francesco Massari, Vedat Onar, Nezir Yaşar Toker, Alex Hanke, Scott A. Pavey, Castrense Savojardo, Pier Luigi Martelli, Rita Casadio, Elisabetta Cilli, Arturo Morales-Muñiz, Barbara Mantovani, Fausto Tinti & Alessia Cariani 

https://doi.org/10.1038/s41598-021-99708-9 

Abstract

Atlantic bluefin tuna (Thunnus thynnus; BFT) abundance was depleted in the late 20th and early 21st century due to overfishing. Historical catch records further indicate that the abundance of BFT in the Mediterranean has been fluctuating since at least the 16th century. Here we build upon previous work on ancient DNA of BFT in the Mediterranean by comparing contemporary (2009–2012) specimens with archival (1911–1926) and archaeological (2nd century BCE–15th century CE) specimens that represent population states prior to these two major periods of exploitation, respectively. We successfully genotyped and analysed 259 contemporary and 123 historical (91 archival and 32 archaeological) specimens at 92 SNP loci that were selected for their ability to differentiate contemporary populations or their association with core biological functions. We found no evidence of genetic bottlenecks, inbreeding or population restructuring between temporal sample groups that might explain what has driven catch fluctuations since the 16th century. We also detected a putative adaptive response, involving the cytoskeletal protein synemin which may be related to muscle stress. However, these results require further investigation with more extensive genome-wide data to rule out demographic changes due to overfishing, and other natural and anthropogenic factors, in addition to elucidating the adaptive drivers related to these.


Published Online: 20 October 2021  

Historical Demographic Processes Dominate Genetic Variation in Ancient Atlantic Cod Mitogenomes

Lourdes Martínez-García, Giada Ferrari, Tom Oosting, Rachel Ballantyne, Inge van der Jagt, Ingrid Ystgaard, Jennifer Harland, Rebecca Nicholson, Sheila Hamilton-Dyer, Helle Tessand Baalsrud, Marine Servane Ono Brieuc, Lane M. Atmore, Finlay Burns, Ulrich Schmölcke, Kjetill S. Jakobsen, Sissel Jentoft, David Orton, Anne Karin Hufthammer, James H. Barrett and Bastiaan Star 

https://doi.org/10.3389/fevo.2021.671281 

Abstract

Ancient DNA (aDNA) approaches have been successfully used to infer the long-term impacts of climate change, domestication, and human exploitation in a range of terrestrial species. Nonetheless, studies investigating such impacts using aDNA in marine species are rare. Atlantic cod (Gadus morhua), is an economically important species that has experienced dramatic census population declines during the last century. Here, we investigated 48 ancient mitogenomes from historical specimens obtained from a range of archeological excavations in northern Europe dated up to 6,500 BCE. We compare these mitogenomes to those of 496 modern conspecifics sampled across the North Atlantic Ocean and adjacent seas. Our results confirm earlier observations of high levels of mitogenomic variation and a lack of mutation-drift equilibrium—suggestive of population expansion. Furthermore, our temporal comparison yields no evidence of measurable mitogenomic changes through time. Instead, our results indicate that mitogenomic variation in Atlantic cod reflects past demographic processes driven by major historical events (such as oscillations in sea level) and subsequent gene flow rather than contemporary fluctuations in stock abundance. Our results indicate that historical and contemporaneous anthropogenic pressures such as commercial fisheries have had little impact on mitogenomic diversity in a wide-spread marine species with high gene flow such as Atlantic cod. These observations do not contradict evidence that overfishing has had negative consequences for the abundance of Atlantic cod and the importance of genetic variation in implementing conservation strategies. Instead, these observations imply that any measures toward the demographic recovery of Atlantic cod in the eastern Atlantic, will not be constrained by recent loss of historical mitogenomic variation. 

Published Online: 4 June 2021 

Potential applications of biomolecular archaeology to the ecohistory of sea turtles and groupers in Levant coastal antiquity

Rachel M.Winter, Willemien de Kock, Per J.Palsbøll, Canan Çakirlar 

https://doi.org/10.1016/j.jasrep.2021.102872

Abstract

Humans have been exploiting marine resources along the Levantine coast for millennia. Advances in biomolecular archaeology present novel opportunities to understand the exploitation of these taxa in antiquity. We discuss the potential insights generated by applying collagen peptide fingerprinting, ancient DNA analysis, and stable isotope analysis to groupers (Serranidae) and sea turtles (Chelonia mydas and Caretta caretta) in the Levant. When combined with traditional zooarchaeological techniques, biomolecular archaeology offers utility to further investigate human impacts on marine ecosystem

Published Online: 6 March 2021