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EECG Embarkation 2024: GRINFISH. Genomics of Reindhartius hippoglossoides on Inshore Fisheries

About the author

Daniel Estévez-Barcia is a postdoctoral researcher at the Greenland Institute of Natural Resources working in collaboration with several institutions of marine research in the North Atlantic. His work focuses on applying population genomics to fisheries and studying the evolutionary biology and behavior of marine organisms (chiefly fish). Together with other researchers in conservation genomics, he strives to make genomic tools indispensable in fisheries management. Consequently, he has a keen interest in understanding what causes genetic differences between populations, going from adaptation signatures to evolutionary histories; and how to develop comprehensible genetic tools to employ in fisheries advice. Find more about the author here.

The GRINFISH project

Figure 1. Processing Greenland halibut for biological samples onboard the RV Tarajoq. Photo credit: Julius Nielsen.

In all fairness, Greenland halibut (Fig. 1), like many other deep species, is an ugly piece of work. Nonetheless, its active hunting style, almost unique among flatfishes, and the relatively little knowledge we have about it, turn this species in a charismatic fish. Furthermore, it has great commercial relevance in the Nordic countries, or as one of our technicians put it when this creature is all over the wet lab: it smells like money. In the inshore settlements of Greenland, its fishery ensures the survival of Inuit cultural identity, and overall, it accounts for a great percentage of the country’s economy. Following the risk of overfishing in inshore areas and the momentum on genetics research (Ferchaud et al., 2022a, b; Gíslason et al., 2023; Estévez-Barcia et al., submitted), and the possible mismatch between stocks and biological populations (Vihtakari et al., 2022, Úbeda et al., 2023; Estévez-Barcia et al., submitted), the GRINFISH project focuses on exploring the genomic differences between inshore and offshore fisheries which may contribute towards sustainable exploitation of this freaky fish.


Figure 2. Distribution of samples for the GRINFISH project.

Having received the EECG award, my project can expand, incorporating samples from the Canadian site, as well as an outgroup from the Bering Sea (Fig. 2). With genomic material from these locations, we can assess whether genetic differences between offshore and inshore populations extend in all the west North Atlantic. As in many other studies in population genomics, we will study the differentiation at both selective and selectively neutral regions of the genome. For the later, genomic data will be combined with environmental data, undertaking in this way a classical seascape genomics approach. Low genetic differentiation is expected, given the high vagility of this species (Vihtakari et al., 2022) and previous genetic studies (e.g. Roy et al. 2014), but regional adaptive differences have also been discovered (Ferchaud et al., 2022b). With the relatively recent developments on next generation sequencing (Therkildsen and Palumbi, 2017), we can investigate if these patterns keep in the Greenlandic case. Complementary to studying the genomic differentiation patterns in the focused distribution, we will also estimate indicators of relevance for fisheries such as the effective population sizes (when feasible) and the migratory exchange between areas.

Finally, the award also allows for the opportunity of transmitting the knowledge derived from genomics to local communities, so a more integral dialogue between scientists and fishers can form. This will take the form of an interactive presentation in an indigenous community, highly dependent on fishing. It is my hope that this helps facilitating the integration of genomic tools in fishery management.


Estévez-Barcia, D., D. Roy, M. Vihtakari, D. Gíslason, M. Lindegren, A. Christensen, M. Treble, L. Wheeland, J. Úbeda, A. Nogueira, K. Hedges, A. Láruson, A. Mateos Rivera, G. Dahle, J-I. Westgaard, B. Elvarsson, O. T. Albert, J. Boje, T. Johansen (In review). Sex influence on the genetic structure of Greenland halibut, Reinhardtius hippglossoides (Walbaum, 1792), in the North Atlantic. Mol. Ecol.

Ferchaud, A.-L., C. Mérot, E. Normandeau, J. Ragoussis, C. Babin, H. Djambazian, P. Bérubé, C. Audet, M. Treble, W. Walkusz, and L. Bernatchez. (2022a). Chromosome-level assembly reveals a putative Y-autosomal fusion in the sex determination system of the Greenland Halibut (Reinhardtius hippoglossoides). G3: Genes Genomes Genet. 12:jkab376.

Ferchaud, A.-L., E. Normandeau, C. Babin, K. Præbel, R. Hedeholm, C. Audet, J. Morgan, M. Treble, W. Walkusz, P. Sirois, and L. Bernatchez. (2022b). A cold-water fish striving in a warming ocean Insights from whole-genome sequencing of the Greenland halibut in the Northwest Atlantic. Front. Mar. Sci. 9:992504.

Gíslason, D., D. Estévez-Barcia, S. Sveinsson, A. Hansen, D. Roy, M. Treble, J. Boje, M. Vihtakari, B. Þ. Elvarsson, K. Hedges, E. H. Hallfredsson, and T. Johansen. (2023). Population structure discovered in juveniles of Greenland halibut (Reinhardtius hippoglossoides Walbaum, 1792). ICES J. Mar. Sci. 80: 889-896.

Roy, D., D. C. Hardie, M. A. Treble, J. D. Reist, and D. E. Ruzzante. (2014). Evidence supporting panmixia in Greenland halibut (Reinhardtius hippoglossoides) in the Northwest Atlantic. Can. J. Fish. Aquat. Sci. 71:763–774.

Therkildsen, N. O., and S. R. Palumbi. (2017). Practical low-coverage genome wide sequencing of hundreds of individually barcoded samples for population and evolutionary genomics in nonmodel species. Mol. Ecol. Resour. 17:194–208.

Úbeda, J., A. Nogueira, N. Tolimieri, M. Vihtakari, B. Elvarsson, M. Treble, and J. Boje. (2023). Using multivariate autoregressive state-space models to examine stock structure of Greenland halibut in the North Atlantic. Fisheries Manag. Ecol. 30:521–535.

Vihtakari, M., B. Þ. Elvarsson, M. Treble, A. Nogueira, K. Hedges, N. E. Hussey, L. Wheeland, D. Roy, L. H. Ofstad, E. H. Hallfredsson, A. Barkley, D. Estévez-Barcia, R. Nygaard, B. Healey, P. Steingrund, T. Johansen, O. T. Albert, and J. Boje. (2022). Migration patterns of Greenland halibut in the North Atlantic revealed by a compiled mark–recapture dataset. ICES J. Mar. Sci. 79: 1902-1917.

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