Skýrslur

NorwLobster: Proceedings from a workshop on Norway lobster fisheries in the Nordic countries, held in Copenhagen 13th and 14th of May 2024

Útgefið:

09/09/2024

Höfundar:

Gunnar Þórðarson and Sigurjón Arason

Styrkt af:

AG fisk (Nordic Council’s working group for fisheries cooperation)

Tengiliður

Gunnar Þórðarson

Svæðisstjóri

gunnar.thordarson@matis.is

There is considerable variation between countries how the species (Nephrops) is caught. Some countries rely largely on creeling (pot fishing) while bottom trawling is the common approach in other regions. Most common in Scandinavia is a combination of both systems, trawling in open sea and deep water, and pot fishing within fjords in shallow water. There are no considerable conflicts between the two groups.

There are pros and cons in both trap fishing and trawling for Nephrops. Both methods have some environmental impact, and both affect the Nephrops stock. Both methods need to respond to increased demands on awareness in environmental issues and sustainable fishing.

The effects of bottom trawling on potential habitat destruction were discussed. Recent developments in fishing gear technology were introduced and evaluation on future directions explored.

Common outcome from the meeting was a need for further research and lack of knowledge on stock assessment and biology. Another outcome was the need for all stakeholders to share information and increase cooperation in the future.

Participants agreed on the severity of the black market for Nephromas, and the damage it does for the value chain, and making stock assessment insignificant. Discharging is another important point regarding running an economical sustainable fishery. Homepage: https://norwlobster.com/

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Population genetics of the Icelandic Nephrops norvegius stock / Stofnerfðafræði leturhumars á Íslandsmiðum

Útgefið:

01/06/2010

Höfundar:

Sigurlaug Skírnisdóttir, Sigurbjörg Hauksdóttir, Kristinn Ólafsson, Christophe Pampouli, Hrafnkell Eiríksson, Steinunn Á. Magnúsdóttir, Guðmundur H. Gunnarsson, Guðmundur Ó. Hreggviðsson, Sigríður Hjörleifsdóttir

Styrkt af:

Verkefnasjóður sjávarútvegsins (The Icelandic Fisheries Research Fund), Nýsköpunarsjóður námsmanna

Tengiliður

Sigurlaug Skírnisdóttir

Verkefnastjóri

sigurlaug.skirnisdottir@matis.is

Population genetics of the Icelandic Nephrops norvegius stock / Stofnerfðafræði leturhumars á Íslandsmiðum

Eins og nafn verkefnisins „Stofnerfðafræði leturhumars á Íslandsmiðum“ gefur til kynna, þá var markmið verkefnisins að skoða stofngerð leturhumars (Nephrops norvegicus) á Íslandsmiðum en stofngerðarrannsóknir eru mikilvægur þáttur fyrir sjálfbæra veiðistjórnun. Markmið verkefnis voru í megindráttum þau að þróa ný erfðamörk til að meta erfðabreytileika innan og milli landfræðilegra aðskildra veiðisvæða við Ísland, að skilgreina faðerni eggjamassa kvendýra af aðskildum veiðisvæðum til að varpa ljósi á æxlunarferli leturhumars og að setja saman áætlun um veiðistjórnun þar sem tekið væri tillit til stofnerfðafræðilegra þátta. Erfðagreining felst í því að nota svonefnd erfðamörk en þau byggja á ákveðnum DNA röðum sem eru á einhvern hátt greinanlegar í erfðamenginu. Algengast er að nota erfðamörk sem byggjast á endurteknum stuttröðum (2-6 basar) sem vitað er að séu breytilegar á milli einstaklinga sömu tegundar. Þessi svæði eru því breytileg í lengd á milli einstaklinga og gerir þau því að hentugum kosti. Erfðagreining er mjög öflug tækni sem nota má til einstaklingsgreininga í hópi lífvera. Þessari aðferð er nú í vaxandi mæli beitt til foreldragreininga, til að meta stofngerð, til rekjanleika rannsókna og til að hraða markvissum kynbótum.Yfirleitt þarf að nota 5-15 mismunandi erfðamörk til að aðgreina einstaklinga. Mikill hluti þróunarvinnu felst því í að finna bestu aðstæður fyrir PCR hvörf þar sem hægt er að nota sem flest erfðamörk í einu hvarfi (multiplex) og samtímakeyrslur á raðgreiningavél. Vel gerð erfðagreiningasett sem eru auðveld og ódýr í notkun og gefa miklar upplýsingar og góða greiningarhæfni eru mjög gagnleg til margvíslegra nota. Þau eru því verðmætar afurðir og markaðsvara, þar sem bæði má selja erfðagreiningar og þjónustu sem á þeim byggja. Í verkefninu voru þróuð átta ný erfðamörk fyrir leturhumar og þau notuð til að greina sýni frá aðskildum landfræðilegum veiðisvæðum við Ísland en skosk leturhumarsýni voru höfð sem úthópur. Að auki voru fjögur áður birt erfðamörk notuð til greininganna. Niðurstöður greininga með þessum 12 erfðamörkum frá landafræðilega aðskildum svæðum (ásamt úthópnum) sýndu ekki marktækan erfðafræðilegan mun leturhumars á milli svæðanna. Afrakstur verkefnisins hefur verið birtur í greinum og nemendaverkefni. Nemendaritgerðin ber titilinn „Development of microsatellite multiplex systems for Nephrops norvegicus“ og er eftir Sóleyju Valgeirsdóttur. Búið er að samþykkja eina grein til birtingar í verkefninu en þar er átta nýjum erfðamörkunum lýst. Heiti greinarinnar er: „Isolation and characterization of eight new microsatellite loci in the Norway lobster, Nephrops norvegicus (Linnaeus, 1758)“ (samþykkt til birtingar í tímaritinu Molecular Ecology Resources, Appendix 1). Önnur grein hefur verið send inn til birtingar í tímaritinu ICES Journal of Marine Science undir heitinu „A pilot genetic study revealed the absence of spatial genetic structure of the Norway lobster (Nephrops norvegicus) at fishing grounds in Icelandic waters“ en hún fjallar um stofngerð leturhumars á Íslandsmiðum þar sem leturhumar frá Skotlandi var hafður sem úthópur (Appendix 2).

The genetic structure of population and mating behavior of exploited marine species are important criterions for effective fisheries management. The distribution of Nephrops norvegicus, Norway lobster, in Icelandic waters is limited to the warmer sea of the south coast. The distribution of the Icelandic stock can be divided into ten geographical areas but the main aim of this project was to develop microsatellite markers to use for the genetics analysis and to analyze whether the lobsters in each area are a self-contained unit stock or not. The aim was furthermore to determine the paternity of egg masses from individual females, and thus elucidate the breeding structure in Icelandic waters. The final goal was to produce a plan for the conservation and management of genetic resources in the Icelandic Norway lobster stock taking into account possible natural population diversity. Microsatellites are short sequence repeats of 2-6 bases found in all prokaryotic and eukaryotic genomes analyzed to date. Microsatellites are variable, which means the number of repeats in a specific area of the DNA variants between the different members of a species. Consequently, the alleles of the microsatellites differ by the length. The different alleles and thus the different length of the microsatellites can be caused by insertion or deletion of one or more repeats during the DNA replication. These sequences are usually under a high degree of length variability and that makes them as powerful genetic markers. Therefore, microsatellites are suitable for population genetics, for family tracing in breeding programs, genetic monitoring, and kinship studies as well as tracing of origin. Usually, 5-15 microsatellites are enough to discriminate between individuals. A microsatellite multiplex system is the use of multiple, unique primer sets in a single PCR mixture to produce amplicons of varying sizes, specific to different DNA sequences. By targeting multiple loci at once, additional information may be gained from a single reaction. It is a great advantage that microsatellite markers can be run in multiplex assay systems. Larger numbers of samples and smaller DNA quantities can then be genotyped at once, saving time and money. This also minimizes the risk of handling errors. In this study we developed eight new microsatellite markers that were used to characterize the genetic diversity of Norway lobster, in and between isolated geographical areas in Icelandic waters, and an out-group sample from Scotland. In addition, four previously published microsatellite markers were used for the analysis. The microsatellites did not detect significant genetic differentiation among the location sampled, not even among Icelandic samples and the out-group collected in Scotland. The outcomes of the project are two papers and one student report. The report is titled „Development of microsatellite multiplex systems for Nephrops norvegicus“ by Sóley Valgeirsdóttir. The first paper is titled; „Isolation and characterization of eight new microsatellite loci in the Norway lobster, Nephrops norvegicus (Linnaeus, 1758)“ where the eight new loci are described (Molecular Ecology Resources; Appendix 1; accepted for publication). The second paper is titled „A pilot genetic study revealed the absence of spatial genetic structure of the Norway lobster (Nephrops norvegicus) at fishing grounds in Icelandic waters“ (ICES Journal of Marine Science; Appendix 2; submitted).

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