Ahead of Print article · Journal article
Genetic analyses reveal complex dynamics within a marine fish management area
National Institute of Aquatic Resources, Technical University of Denmark1
Section for Marine Living Resources, National Institute of Aquatic Resources, Technical University of Denmark2
Section for Oceans and Arctic, National Institute of Aquatic Resources, Technical University of Denmark3
Section for Freshwater Fisheries Ecology, National Institute of Aquatic Resources, Technical University of Denmark4
Johann Heinrich von Thunen Institute5
Helmholtz Centre for Ocean Research Kiel6
Section for Monitoring and Data, National Institute of Aquatic Resources, Technical University of Denmark7
Section for Ecosystem based Marine Management, National Institute of Aquatic Resources, Technical University of Denmark8
Genetic data have great potential for improving fisheries management by identifying the fundamental management units—that is, the biological populations—and their mixing. However, so far, the number of practical cases of marine fisheries management using genetics has been limited. Here, we used Atlantic cod in the Baltic Sea to demonstrate the applicability of genetics to a complex management scenario involving mixing of two genetically divergent populations.
Specifically, we addressed several assumptions used in the current assessment of the two populations. Through analysis of 483 single nucleotide polymorphisms (SNPs) distributed across the Atlantic cod genome, we confirmed that a model of mechanical mixing, rather than hybridization and introgression, best explained the pattern of genetic differentiation.
Thus, the fishery is best monitored as a mixed‐stock fishery. Next, we developed a targeted panel of 39 SNPs with high statistical power for identifying population of origin and analyzed more than 2,000 tissue samples collected between 2011 and 2015 as well as 260 otoliths collected in 2003/2004. These data provided high spatial resolution and allowed us to investigate geographical trends in mixing, to compare patterns for different life stages and to investigate temporal trends in mixing.
We found similar geographical trends for the two time points represented by tissue and otolith samples and that a recently implemented geographical management separation of the two populations provided a relatively close match to their distributions. In contrast to the current assumption, we found that patterns of mixing differed between juveniles and adults, a signal likely linked to the different reproductive dynamics of the two populations.
Collectively, our data confirm that genetics is an operational tool for complex fisheries management applications. We recommend focussing on developing population assessment models and fisheries management frameworks to capitalize fully on the additional information offered by genetically assisted fisheries monitoring.
Language: | English |
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Publisher: | John Wiley and Sons Inc. |
Year: | 2018 |
Pages: | 830-844 |
ISSN: | 17524571 and 17524563 |
Types: | Ahead of Print article and Journal article |
DOI: | 10.1111/eva.12760 |
ORCIDs: | Hansen, Jakob Hemmer , Bekkevold, Dorte , 0000-0002-8961-4337 , Hüssy, Karin , Baktoft, Henrik , Huwer, Bastian , Mosegaard, Henrik , Eg Nielsen, Einar , Storr-Paulsen, Marie and Eero, Margit |