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Małachowicz M, Krasnov A, Wenne R. Diverse Transcriptome Responses to Salinity Change in Atlantic Cod Subpopulations. Cells 2023; 12:2760. [PMID: 38067188 PMCID: PMC10706248 DOI: 10.3390/cells12232760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 11/25/2023] [Accepted: 11/29/2023] [Indexed: 12/18/2023] Open
Abstract
Adaptation to environmental variation caused by global climate change is a significant aspect of fisheries management and ecology. A reduction in ocean salinity is visible in near-shore areas, especially in the Baltic Sea, where it is affecting the Atlantic cod population. Cod is one of the most significant teleost species, with high ecological and economical value worldwide. The population of cod in the Baltic Sea has been traditionally divided into two subpopulations (western and eastern) existing in higher- and lower-salinity waters, respectively. In recent decades, both Baltic cod subpopulations have declined massively. One of the reasons for the poor condition of cod in the Baltic Sea is environmental factors, including salinity. Thus, in this study, an oligonucleotide microarray was applied to explore differences between Baltic cod subpopulations in response to salinity fluctuations. For this purpose, an exposure experiment was conducted consisting of salinity elevation and reduction, and gene expression was measured in gill tissue. We found 400 differentially expressed genes (DEGs) involved in the immune response, metabolism, programmed cell death, cytoskeleton, and extracellular matrix that showed a subpopulation-dependent pattern. These findings indicate that osmoregulation in Baltic cod is a complex process, and that western and eastern Baltic cod subpopulations respond differently to salinity changes.
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Affiliation(s)
- Magdalena Małachowicz
- Institute of Oceanology Polish Academy of Sciences, Powstanców Warszawy 55, 81-712 Sopot, Poland;
| | - Aleksei Krasnov
- Department of Fish Health, Nofima—Norwegian Institute of Food, Fisheries and Aquaculture Research, Osloveien 1, NO-1431 Ås, Norway;
| | - Roman Wenne
- Institute of Oceanology Polish Academy of Sciences, Powstanców Warszawy 55, 81-712 Sopot, Poland;
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2
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Helmerson C, Weist P, Brieuc MSO, Maurstad MF, Schade FM, Dierking J, Petereit C, Knutsen H, Metcalfe J, Righton D, André C, Krumme U, Jentoft S, Hanel R. Evidence of hybridization between genetically distinct Baltic cod stocks during peak population abundance(s). Evol Appl 2023; 16:1359-1376. [PMID: 37492148 PMCID: PMC10363836 DOI: 10.1111/eva.13575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 06/06/2023] [Accepted: 06/14/2023] [Indexed: 07/27/2023] Open
Abstract
Range expansions can lead to increased contact of divergent populations, thus increasing the potential of hybridization events. Whether viable hybrids are produced will most likely depend on the level of genomic divergence and associated genomic incompatibilities between the different entities as well as environmental conditions. By taking advantage of historical Baltic cod (Gadus morhua) otolith samples combined with genotyping and whole genome sequencing, we here investigate the genetic impact of the increased spawning stock biomass of the eastern Baltic cod stock in the mid 1980s. The eastern Baltic cod is genetically highly differentiated from the adjacent western Baltic cod and locally adapted to the brackish environmental conditions in the deeper Eastern basins of the Baltic Sea unsuitable for its marine counterparts. Our genotyping results show an increased proportion of eastern Baltic cod in western Baltic areas (Mecklenburg Bay and Arkona Basin)-indicative of a range expansion westwards-during the peak population abundance in the 1980s. Additionally, we detect high frequencies of potential hybrids (including F1, F2 and backcrosses), verified by whole genome sequencing data for a subset of individuals. Analysis of mitochondrial genomes further indicates directional gene flow from eastern Baltic cod males to western Baltic cod females. Our findings unravel that increased overlap in distribution can promote hybridization between highly divergent populations and that the hybrids can be viable and survive under specific and favourable environmental conditions. However, the observed hybridization had seemingly no long-lasting impact on the continuous separation and genetic differentiation between the unique Baltic cod stocks.
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Affiliation(s)
- Cecilia Helmerson
- Centre for Ecological and Evolutionary SynthesisDepartment of BiosciencesUniversity of OsloOsloNorway
| | - Peggy Weist
- Thünen Institute of Fisheries EcologyBremerhavenGermany
| | - Marine Servane Ono Brieuc
- Centre for Ecological and Evolutionary SynthesisDepartment of BiosciencesUniversity of OsloOsloNorway
- Institute of Marine ResearchBergenNorway
| | - Marius F. Maurstad
- Centre for Ecological and Evolutionary SynthesisDepartment of BiosciencesUniversity of OsloOsloNorway
| | | | - Jan Dierking
- GEOMAR Helmholtz Centre for Ocean Research KielGermany
| | | | - Halvor Knutsen
- Institute of Marine ResearchBergenNorway
- Centre for Coastal ResearchUniversity of AgderKristiansandNorway
| | - Julian Metcalfe
- Centre for Environment Fisheries and Aquaculture ScienceLowestoftUK
| | - David Righton
- Centre for Environment Fisheries and Aquaculture ScienceLowestoftUK
| | - Carl André
- Department of Marine Sciences – TjärnöUniversity of GothenburgStrömstadSweden
| | - Uwe Krumme
- Thünen Institute of Baltic Sea FisheriesRostockGermany
| | - Sissel Jentoft
- Centre for Ecological and Evolutionary SynthesisDepartment of BiosciencesUniversity of OsloOsloNorway
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3
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Living apart together: Long-term coexistence of Baltic cod stocks associated with depth-specific habitat use. PLoS One 2022; 17:e0274476. [PMID: 36170259 PMCID: PMC9518848 DOI: 10.1371/journal.pone.0274476] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 08/29/2022] [Indexed: 12/02/2022] Open
Abstract
Coexistence of fish populations (= stocks) of the same species is a common phenomenon. In the Baltic Sea, two genetically divergent stocks of Atlantic cod (Gadus morhua), Western Baltic cod (WBC) and Eastern Baltic cod (EBC), coexist in the Arkona Sea. Although the relative proportions of WBC and EBC in this area are considered in the current stock assessments, the mixing dynamics and ecological mechanisms underlying coexistence are not well understood. In this study, a genetically validated otolith shape analysis was used to develop the most comprehensive time series of annual stock mixing data (1977–2019) for WBC and EBC. Spatio-temporal mixing analysis confirmed that the two stocks coexist in the Arkona Sea, albeit with fluctuating mixing proportions over the 43-year observation period. Depth-stratified analysis revealed a strong correlation between capture depth and stock mixing patterns, with high proportions of WBC in shallower waters (48–61% in <20m) and increasing proportions of EBC in deeper waters (50–86% in 40-70m). Consistent depth-specific mixing patterns indicate stable differences in depth distribution and habitat use of WBC and EBC that may thus underlie the long-term coexistence of the two stocks in the Arkona Sea. These differences were also reflected in significantly different proportions of WBC and EBC in fisheries applying passive gears in shallower waters (more WBC) and active gears in deeper waters (more EBC). This highlights the potential for fishing gear-specific exploitation of different stocks, and calls for stronger consideration of capture depth and gear type in stock assessments. This novel evidence provides the basis for improved approaches to research, monitoring and management of Baltic cod stocks.
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Jónsson EP, Campana SE, Sólmundsson J, Jakobsdóttir KB, Bárðarson H. The effect of growth rate on otolith-based discrimination of cod (Gadus morhua) ecotypes. PLoS One 2021; 16:e0247630. [PMID: 34587180 PMCID: PMC8480848 DOI: 10.1371/journal.pone.0247630] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 09/09/2021] [Indexed: 01/10/2023] Open
Abstract
Otolith shape has previously been used to identify ecotypes within the Icelandic cod (Gadus morhua) stock, using DST profiles to validate the results. Fish otolith shape variation has repeatedly been found to be largely determined by growth rate. To examine the effect of growth rate on the relationship between otolith shape and cod ecotypes (using the Pan I genotype as a proxy for ecotype), 826 archived sagittal otoliths collected over a 58 year sampling period were retrieved, the individual growth rate calculated, and otolith shape described using both Normalized Elliptic Fourier transform and Discrete Wavelet transform. Discriminant functions of otolith shape successfully classified ecotype, whether using Fourier or Wavelet descriptors, but only when excluding a heterozygous genotype from the analysis. The otolith shape variability of this genotype lowered the classification success, while otolith shape, in turn, was significantly affected by growth rate and cohort. Growth rate differences previously reported for the ecotypes were present, but were less marked than expected and indeed, growth rate variance attributable to ecotype identity was dwarfed by cohort- and location-related variance in growth. Such a strong effect of growth rate suggests that cod ecotype discrimination based on otolith shape is sensitive to both temporal and spatial variations in growth, which can mask the effect of ecotype-related growth rate differences on otolith shape.
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Affiliation(s)
- Einar Pétur Jónsson
- School of Engineering and Natural Sciences, University of Iceland, Askja, Reykjavík, Iceland
- Marine and Freshwater Research Institute, Hafnarfjörður, Iceland
- * E-mail:
| | - Steven E. Campana
- School of Engineering and Natural Sciences, University of Iceland, Askja, Reykjavík, Iceland
| | - Jón Sólmundsson
- Marine and Freshwater Research Institute, Hafnarfjörður, Iceland
| | | | - Hlynur Bárðarson
- Marine and Freshwater Research Institute, Hafnarfjörður, Iceland
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5
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Tikochinski Y, Tamir S, Simon-Blecher N, Motro U, Achituv Y. A star is torn-molecular analysis divides the Mediterranean population of Poli's stellate barnacle, Chthamalus stellatus (Cirripedia, Chtamalidae). PeerJ 2021; 9:e11826. [PMID: 34327065 PMCID: PMC8308608 DOI: 10.7717/peerj.11826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/30/2021] [Indexed: 11/20/2022] Open
Abstract
Poli's stellate barnacle, Chthamalus stellatus Poli, populates the Mediterranean Sea, the North-Eastern Atlantic coasts, and the offshore Eastern Atlantic islands. Previous studies have found apparent genetic differences between the Atlantic and the Mediterranean populations of C. stellatus, suggesting possible geological and oceanographic explanations for these differences. We have studied the genetic diversity of 14 populations spanning from the Eastern Atlantic to the Eastern Mediterranean, using two nuclear genes sequences revealing a total of 63 polymorphic sites. Both genotype-based, haplotype-based and the novel SNP distribution population-based methods have found that these populations represent a geographic cline along the west to east localities. The differences in SNP distribution among populations further separates a major western cluster into two smaller clusters, the Eastern Atlantic and the Western Mediterranean. It also separates the major eastern cluster into two smaller clusters, the Mid-Mediterranean and Eastern Mediterranean. We suggested here environmental conditions like surface currents, water salinity and temperature as probable factors that have formed the population structure. We demonstrate that C. stellatus is a suitable model organism for studying how geological events and hydrographic conditions shape the fauna in the Mediterranean Sea.
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Affiliation(s)
- Yaron Tikochinski
- Faculty of Marine Sciences, Ruppin Academic Center, Mikhmoret, Israel
| | - Sharon Tamir
- Faculty of Marine Sciences, Ruppin Academic Center, Mikhmoret, Israel
| | - Noa Simon-Blecher
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Uzi Motro
- Department of Ecology, Evolution and Behavior, and the Federmann Center for the Study of Rationality, the Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yair Achituv
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
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6
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Möllmann C, Cormon X, Funk S, Otto SA, Schmidt JO, Schwermer H, Sguotti C, Voss R, Quaas M. Tipping point realized in cod fishery. Sci Rep 2021; 11:14259. [PMID: 34253825 PMCID: PMC8275682 DOI: 10.1038/s41598-021-93843-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Accepted: 07/01/2021] [Indexed: 11/10/2022] Open
Abstract
Understanding tipping point dynamics in harvested ecosystems is of crucial importance for sustainable resource management because ignoring their existence imperils social-ecological systems that depend on them. Fisheries collapses provide the best known examples for realizing tipping points with catastrophic ecological, economic and social consequences. However, present-day fisheries management systems still largely ignore the potential of their resources to exhibit such abrupt changes towards irreversible low productive states. Using a combination of statistical changepoint analysis and stochastic cusp modelling, here we show that Western Baltic cod is beyond such a tipping point caused by unsustainable exploitation levels that failed to account for changing environmental conditions. Furthermore, climate change stabilizes a novel and likely irreversible low productivity state of this fish stock that is not adapted to a fast warming environment. We hence argue that ignorance of non-linear resource dynamics has caused the demise of an economically and culturally important social-ecological system which calls for better adaptation of fisheries systems to climate change.
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Affiliation(s)
- Christian Möllmann
- Institute of Marine Ecosystem and Fisheries Science (IMF), Center for Earth System Research and Sustainability (CEN), Hamburg University, Hamburg, Germany.
| | - Xochitl Cormon
- Institute of Marine Ecosystem and Fisheries Science (IMF), Center for Earth System Research and Sustainability (CEN), Hamburg University, Hamburg, Germany
| | - Steffen Funk
- Institute of Marine Ecosystem and Fisheries Science (IMF), Center for Earth System Research and Sustainability (CEN), Hamburg University, Hamburg, Germany
| | - Saskia A Otto
- Institute of Marine Ecosystem and Fisheries Science (IMF), Center for Earth System Research and Sustainability (CEN), Hamburg University, Hamburg, Germany
| | - Jörn O Schmidt
- Center for Ocean and Society (CeOS), Christian-Albrechts-University Kiel, Kiel, Germany.,International Council for the Exploration of the Sea (ICES), Copenhagen, Denmark
| | - Heike Schwermer
- Institute of Marine Ecosystem and Fisheries Science (IMF), Center for Earth System Research and Sustainability (CEN), Hamburg University, Hamburg, Germany.,Center for Ocean and Society (CeOS), Christian-Albrechts-University Kiel, Kiel, Germany
| | - Camilla Sguotti
- Institute of Marine Ecosystem and Fisheries Science (IMF), Center for Earth System Research and Sustainability (CEN), Hamburg University, Hamburg, Germany
| | - Rudi Voss
- Center for Ocean and Society (CeOS), Christian-Albrechts-University Kiel, Kiel, Germany.,German Centre for Integrative Biodiversity Research (iDiv), Halle-Jena-Leipzig, Leipzig, Germany
| | - Martin Quaas
- German Centre for Integrative Biodiversity Research (iDiv), Halle-Jena-Leipzig, Leipzig, Germany
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7
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Funk S, Frelat R, Möllmann C, Temming A, Krumme U. The forgotten feeding ground: patterns in seasonal and depth-specific food intake of adult cod Gadus morhua in the western Baltic Sea. JOURNAL OF FISH BIOLOGY 2021; 98:707-722. [PMID: 33200410 DOI: 10.1111/jfb.14615] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 11/05/2020] [Accepted: 11/15/2020] [Indexed: 06/11/2023]
Abstract
This study presents the diet composition of western Baltic cod Gadus morhua based on 3150 stomachs sampled year-round between 2016 and 2017 using angling, gillnetting and bottom trawling, which enhanced the spatio-temporal coverage of cod habitats. Cod diet composition in shallow areas (<20 m depth) was dominated by benthic invertebrate species, mainly the common shore crab Carcinus maneas. Compared to historic diet data from the 1960s and 1980s (limited to depth >20 m), the contribution of herring Clupea harengus decreased and round goby Neogobius melanostomus occurred as a new prey species. Statistical modelling revealed significant relationships between diet composition, catch depth, fish length and season. Generalized additive modelling identified a negative relationship between catch depth and stomach content weight, suggesting reduced food intake in winter when cod use deeper areas for spawning and during peak summer when cod tend to avoid high water temperatures. The results of this study highlight the importance of shallow coastal areas as major feeding habitats of adult cod in the western Baltic Sea, which were previously unknown because samples were restricted to deeper trawlable areas. The results strongly suggest that historic stomach analyses overestimated the role of forage fish and underestimated the role of invertebrate prey. Eventually, this study shows the importance of a comprehensive habitat coverage for unbiased stomach sampling programmes to provide a more reliable estimation of top predator diet, a key information for food web analyses and multispecies models.
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Affiliation(s)
- Steffen Funk
- Department of Biology, Institute of Marine Ecosystem and Fishery Science, Centre for Earth System Research and Sustainability (CEN), University of Hamburg, Hamburg, Germany
| | - Romain Frelat
- Department of Biology, Institute of Marine Ecosystem and Fishery Science, Centre for Earth System Research and Sustainability (CEN), University of Hamburg, Hamburg, Germany
- Aquaculture and Fisheries Group, Wageningen University, Wageningen, The Netherlands
| | - Christian Möllmann
- Department of Biology, Institute of Marine Ecosystem and Fishery Science, Centre for Earth System Research and Sustainability (CEN), University of Hamburg, Hamburg, Germany
| | - Axel Temming
- Department of Biology, Institute of Marine Ecosystem and Fishery Science, Centre for Earth System Research and Sustainability (CEN), University of Hamburg, Hamburg, Germany
| | - Uwe Krumme
- Thünen Institute of Baltic Sea Fisheries, Rostock, Germany
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Walker VK, Das P, Li P, Lougheed SC, Moniz K, Schott S, Qitsualik J, Koch I. Identification of Arctic Food Fish Species for Anthropogenic Contaminant Testing Using Geography and Genetics. Foods 2020; 9:foods9121824. [PMID: 33302601 PMCID: PMC7764770 DOI: 10.3390/foods9121824] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/27/2020] [Accepted: 12/03/2020] [Indexed: 02/07/2023] Open
Abstract
The identification of food fish bearing anthropogenic contaminants is one of many priorities for Indigenous peoples living in the Arctic. Mercury (Hg), arsenic (As), and persistent organic pollutants including polychlorinated biphenyls (PCBs) are of concern, and these are reported, in some cases for the first time, for fish sampled in and around King William Island, located in Nunavut, Canada. More than 500 salmonids, comprising Arctic char, lake trout, lake whitefish, and ciscoes, were assayed for contaminants. The studied species are anadromous, migrating to the ocean to feed in the summers and returning to freshwater before sea ice formation in the autumn. Assessments of muscle Hg levels in salmonids from fishing sites on King William Island showed generally higher levels than from mainland sites, with mean concentrations generally below guidelines, except for lake trout. In contrast, mainland fish showed higher means for As, including non-toxic arsenobetaine, than island fish. Lake trout were highest in As and PCB levels, with salmonid PCB congener analysis showing signatures consistent with the legacy of cold-war distant early warning stations. After DNA-profiling, only 4–32 Arctic char single nucleotide polymorphisms were needed for successful population assignment. These results support our objective to demonstrate that genomic tools could facilitate efficient and cost-effective cluster assignment for contaminant analysis during ocean residency. We further suggest that routine pollutant testing during the current period of dramatic climate change would be helpful to safeguard the wellbeing of Inuit who depend on these fish as a staple input to their diet. Moreover, this strategy should be applicable elsewhere.
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Affiliation(s)
- Virginia K. Walker
- Department of Biology, Queen’s University, Kingston, ON K7L 3N6, Canada; (P.D.); (P.L.); (S.C.L.); (K.M.); (I.K.)
- School of Environmental Studies, Queen’s University, Kingston, ON K7L 3N6, Canada
- Correspondence:
| | - Pranab Das
- Department of Biology, Queen’s University, Kingston, ON K7L 3N6, Canada; (P.D.); (P.L.); (S.C.L.); (K.M.); (I.K.)
| | - Peiwen Li
- Department of Biology, Queen’s University, Kingston, ON K7L 3N6, Canada; (P.D.); (P.L.); (S.C.L.); (K.M.); (I.K.)
| | - Stephen C. Lougheed
- Department of Biology, Queen’s University, Kingston, ON K7L 3N6, Canada; (P.D.); (P.L.); (S.C.L.); (K.M.); (I.K.)
| | - Kristy Moniz
- Department of Biology, Queen’s University, Kingston, ON K7L 3N6, Canada; (P.D.); (P.L.); (S.C.L.); (K.M.); (I.K.)
| | - Stephan Schott
- School of Public Policy and Administration, Carleton University, Ottawa, ON K1S 5B6, Canada;
| | - James Qitsualik
- Gjoa Haven Hunters and Trappers Association, Gjoa Haven, NU X0B 1J0, Canada;
| | - Iris Koch
- Department of Biology, Queen’s University, Kingston, ON K7L 3N6, Canada; (P.D.); (P.L.); (S.C.L.); (K.M.); (I.K.)
- Royal Military College, Kingston, ON K7K 7B4, Canada
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9
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Johannesson K, Le Moan A, Perini S, André C. A Darwinian Laboratory of Multiple Contact Zones. Trends Ecol Evol 2020; 35:1021-1036. [DOI: 10.1016/j.tree.2020.07.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 07/25/2020] [Accepted: 07/27/2020] [Indexed: 12/11/2022]
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10
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Quintela M, Kvamme C, Bekkevold D, Nash RDM, Jansson E, Sørvik AG, Taggart JB, Skaala Ø, Dahle G, Glover KA. Genetic analysis redraws the management boundaries for the European sprat. Evol Appl 2020; 13:1906-1922. [PMID: 32908594 PMCID: PMC7463317 DOI: 10.1111/eva.12942] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 02/03/2020] [Accepted: 02/21/2020] [Indexed: 12/12/2022] Open
Abstract
Sustainable fisheries management requires detailed knowledge of population genetic structure. The European sprat is an important commercial fish distributed from Morocco to the Arctic circle, Baltic, Mediterranean, and Black seas. Prior to 2018, annual catch advice on sprat from the International Council for the Exploration of the Sea (ICES) was based on five putative stocks: (a) North Sea, (b) Kattegat-Skagerrak and Norwegian fjords, (c) Baltic Sea, (d) West of Scotland-southern Celtic Seas, and (e) English Channel. However, there were concerns that the sprat advice on stock size estimates management plan inadequately reflected the underlying biological units. Here, we used ddRAD sequencing to develop 91 SNPs that were thereafter used to genotype approximately 2,500 fish from 40 locations. Three highly distinct and relatively homogenous genetic groups were identified: (a) Norwegian fjords; (b) Northeast Atlantic including the North Sea, Kattegat-Skagerrak, Celtic Sea, and Bay of Biscay; and (c) Baltic Sea. Evidence of genetic admixture and possibly physical mixing was detected in samples collected from the transition zone between the North and Baltic seas, but not between any of the other groups. These results have already been implemented by ICES with the decision to merge the North Sea and the Kattegat-Skagerrak sprat to be assessed as a single unit, thus demonstrating that genetic data can be rapidly absorbed to align harvest regimes and biological units.
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Affiliation(s)
| | | | - Dorte Bekkevold
- DTU-Aqua National Institute of Aquatic Resources Technical University of Denmark Silkeborg Denmark
| | | | | | | | - John B Taggart
- Institute of Aquaculture School of Natural Sciences University of Stirling Stirling UK
| | | | - Geir Dahle
- Institute of Marine Research Bergen Norway
| | - Kevin A Glover
- Institute of Marine Research Bergen Norway
- Institute of Biology University of Bergen Bergen Norway
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11
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Wenne R, Bernaś R, Kijewska A, Poćwierz-Kotus A, Strand J, Petereit C, Plauška K, Sics I, Árnyasi M, Kent MP. SNP genotyping reveals substructuring in weakly differentiated populations of Atlantic cod (Gadus morhua) from diverse environments in the Baltic Sea. Sci Rep 2020; 10:9738. [PMID: 32546719 PMCID: PMC7298039 DOI: 10.1038/s41598-020-66518-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 05/11/2020] [Indexed: 01/02/2023] Open
Abstract
Atlantic cod (Gadus morhua) is one of the most important fish species in northern Europe for several reasons including its predator status in marine ecosystems, its historical role in fisheries, its potential in aquaculture and its strong public profile. However, due to over-exploitation in the North Atlantic and changes in the ecosystem, many cod populations have been reduced in size and genetic diversity. Cod populations in the Baltic Proper, Kattegat and North Sea have been analyzed using a species specific single nucleotide polymorphism (SNP) array. Using a subset of 8,706 SNPs, moderate genetic differences were found between subdivisions in three traditionally delineated cod management stocks: Kattegat, western and eastern Baltic. However, an FST measure of population differentiation based on allele frequencies from 588 outlier loci for 2 population groups, one including 5 western and the other 4 eastern Baltic populations, indicated high genetic differentiation. In this paper, differentiation has been demonstrated not only between, but also within western and eastern Baltic cod stocks for the first time, with salinity appearing to be the most important environmental factor influencing the maintenance of cod population divergence between the western and eastern Baltic Sea.
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Affiliation(s)
- Roman Wenne
- Institute of Oceanology, Polish Academy of Sciences, Powstańców Warszawy 55, 81-712, Sopot, Poland.
| | - Rafał Bernaś
- Department of Migratory Fishes in Rutki, Inland Fisheries Institute, Olsztyn, 10-719, Poland
| | - Agnieszka Kijewska
- Institute of Oceanology, Polish Academy of Sciences, Powstańców Warszawy 55, 81-712, Sopot, Poland
| | - Anita Poćwierz-Kotus
- Institute of Oceanology, Polish Academy of Sciences, Powstańców Warszawy 55, 81-712, Sopot, Poland
| | - Jakob Strand
- Arctic Research Centre, Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000, Roskilde, Denmark
| | - Christoph Petereit
- GEOMAR, Helmholtz Centre for Ocean Research Kiel, Research Division 3: Marine Ecology, Research Unit: Evolutionary Ecology of Marine Fishes, Düsternbrooker Weg 20, 24105, Kiel, Germany
- Bruno-Lorenzen-Schule Schleswig, Spielkoppel 6, 24837, Schleswig, Germany
| | - Kęstas Plauška
- Fisheries Service under the Ministry of Agriculture Division of Fisheries Research & Science, Smiltynes 1, 91001, Klaipeda, Lithuania
| | - Ivo Sics
- Institute of Food Safety, Animal Health and Environment "BIOR", Riga, Latvia
| | - Mariann Árnyasi
- Centre for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences (IHA), Faculty of Life Sciences (BIOVIT), Norwegian University of Life Sciences (NMBU), PO Box, 5003, Aas, Norway
| | - Matthew P Kent
- Centre for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences (IHA), Faculty of Life Sciences (BIOVIT), Norwegian University of Life Sciences (NMBU), PO Box, 5003, Aas, Norway
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12
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McQueen K, Mion M, Hilvarsson A, Casini M, Olesen HJ, Hüssy K, Radtke K, Krumme U. Effects of freezing on length and mass measurements of Atlantic cod Gadus morhua in the Baltic Sea. JOURNAL OF FISH BIOLOGY 2019; 95:1486-1495. [PMID: 31631337 DOI: 10.1111/jfb.14171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 10/18/2019] [Indexed: 06/10/2023]
Abstract
An aggregated sample of 925 Atlantic cod Gadus morhua collected by four countries in different regions of the Baltic Sea during different seasons were measured (total length, LT = 161-890 mm and weighed (mass, M = 45-6900 g) both before freezing and after defrosting. The cod were found to decrease significantly in both LT and M following death and frozen storage. There was an average (±SD) change in LT of -2.91% (±0.05%) following freezing, independent of starting LT . Total M changed by -2.65% (±0.14%), independent of starting mass. Shrinkage of LT and M did not differ significantly between 1 and 4 months frozen storage, though LT shrinkage was significantly greater after 1 or 4 months in the freezer compared with after 5 days. There was significant variation in LT and M shrinkage between regions of capture. A significant negative relationship between condition of cod and LT or M change was also observed. Equations to back-calculate fresh LT and M from thawed LT , M and standard length (LS ), gutted LT , gutted LS and gutted M are provided.
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Affiliation(s)
- Kate McQueen
- Thünen Institute of Baltic Sea Fisheries, Rostock, Germany
| | - Monica Mion
- Department of Aquatic Resources, Institute of Marine Research, Swedish University of Agricultural Sciences, Lysekil, Sweden
| | - Annelie Hilvarsson
- Department of Aquatic Resources, Institute of Marine Research, Swedish University of Agricultural Sciences, Lysekil, Sweden
| | - Michele Casini
- Department of Aquatic Resources, Institute of Marine Research, Swedish University of Agricultural Sciences, Lysekil, Sweden
| | - Hans J Olesen
- Technical University of Denmark, National Institute of Aquatic Resources, Kgs. Lyngby, Denmark
| | - Karin Hüssy
- Technical University of Denmark, National Institute of Aquatic Resources, Kgs. Lyngby, Denmark
| | | | - Uwe Krumme
- Thünen Institute of Baltic Sea Fisheries, Rostock, Germany
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