Structural and functional changes of soft-bottom ecosystems in northern fjords invaded by the red king crab (Paralithodes camtschaticus)

The red king crab invaded Norwegian coastal waters in the early 1990s after having been introduced from the northern Pacific to the Russian Barents Sea coast. The crab stock increased rapidly in NE northern Norway in the latter half of the 1990s, and since 2002 there has been a commercial fishery in the eastern invaded areas. The crab is an active predator on benthic fauna especially feeding in deep soft-bottom environments. The present study is a follow-up of previous studies (2007–09) to assess the effects of the king crab predation on soft bottom species composition, ecological functioning and sediment quality. Macroinfauna (> 1 mm) was investigated in three fjord areas in the Varanger region with low, moderate and very high crab abundances, respectively. Compared with data from 1994, most benthic species were markedly reduced in abundance, in particular non-moving burrowing and tube-dwelling polychaetes, bivalves and echinoderms. However, a few species appeared to recover from 2007–09 to 2012. Changes in ecological functioning were assessed using ‘biological traits analysis (BTA)’. Following the crab invasion there was a relative reduction of suspension and surface deposit feeding species, an increase in mobile and predatory organisms and an increase in those with planktotrophic larval development. From low to high crab abundances functioning changed from tube-building, deep deposit feeding and fairly large size to free-living, shallow burrowing and rather small size. With regard to sediment reworking, downward and upward conveyors were reduced whereas surficial modifiers increased. The changes imply that sediment biomixing and bioirrigation were reduced leading to a degraded sedimentary environment. It is suggested that establishing relationships between ecosystem functioning and crab abundances may form the basis for estimating ecological costs of the crab invasion. Such knowledge is important for managing the crab in the Barents Sea area being both a non-indigenous species affecting native ecosystems as well as a valuable resource for commercial fishery.publishedVersio

Os direitos fundamentais na jurisdiçăo constitucional e as cláusulas gerais processuais /

Orientador : Luiz Guilherme MarinoniDissertaçăo (mestrado) - Universidade Federal do Paraná, Setor de Cięncias Jurídicas, Programa de Pós-Graduaçăo em Direito. Defesa: Curitiba, 2006Inclui bibliografi

Microplastic Fiber Emissions From Wastewater Effluents: Abundance, Transport Behavior and Exposure Risk for Biota in an Arctic Fjord

Microfibers (MF) are one of the major classes of microplastic found in the marine environment on a global scale. Very little is known about how they move and distribute from point sources such as wastewater effluents into the ocean. We chose Adventfjorden near the settlement of Longyearbyen on the Arctic Svalbard archipelago as a case study to investigate how microfibers emitted with untreated wastewater will distribute in the fjord, both on a spatial and temporal scale. Fiber abundance in the effluent was estimated from wastewater samples taken during two one-week periods in June and September 2017. Large emissions of MFs were detected, similar in scale to a modern WWTP serving 1.3 million people and providing evidence of the importance of untreated wastewater from small settlements as major local sources for MF emissions in the Arctic. Fiber movement and distribution in the fjord mapped using an online-coupled hydrodynamic-drift model (FVCOM-FABM). For parameterizing a wider spectrum of fibers from synthetic to wool, four different density classes of MFs, i.e., buoyant, neutral, sinking, and fast sinking fibers are introduced to the modeling framework. The results clearly show that fiber class has a large impact on the fiber distributions. Light fibers remained in the surface layers and left the fjord quickly with outgoing currents, while heavy fibers mostly sank to the bottom and deposited in the inner parts of the fjord and along the northern shore. A number of accumulation sites were identified within the fjord. The southern shore, in contrast, was much less affected, with low fiber concentrations throughout the modeling period. Fiber distributions were then compared with published pelagic and benthic fauna distributions in different seasons at selected stations around the fjord. The ratios of fibers to organisms showed a very wide range, indicating hot spots of encounter risk for pelagic and benthic biota. This approach, in combination with in-situ ground-truthing, can be instrumental in understanding microplastic pathways and fate in fjord systems and coastal areas and help authorities develop monitoring and mitigation strategies for microfiber and microplastic pollution in their local waters

Effekter på bunnfauna av nytt fangstredskap for haneskjell - Testing av TauTech's Harvester

På oppdrag av TauTech AS gjennomførte Havforskningsinstituttet i samarbeid med NIVA en undersøkelse hvor målsetningen var å studere effekter på bunnfauna og bunnsedimenter ved bruk av et nytt fangstredskap for haneskjell, heretter kalt Harvester. Selve fangstingen baserer seg på å suge skjellene opp fra bunnen, hvor deler av fangsten sorteres fra på bunnen og ønsket fangst (store haneskjell) blir samlet opp. Forsøket foregikk på et haneskjellfelt på Berg ved Tromsø. I tillegg til undervanns videoopptak ble det gjort skrapetrekk med trekantskrape før og etter operasjonene med Harvester, for å undersøke sammensetningen av bunndyr før og etter operasjonene. Materialet som sorteres ut ved fangstingen ble også undersøkt med hensyn på størrelse på utsorterte haneskjell, sammensetningen av dyr og graden av skader på begge deler. Resultatene viste ingen endringer i sammensetningen av dyr unntatt haneskjell før og etter operasjonene med Harvester. Størstedelen av utsorterte haneskjell var små skjell og skadene på disse var moderate. De resterende dyrene ble inndelt i seks sårbarhetsgrupper basert på noen kriterier og det viste seg at dyr i fem av gruppene hadde små og moderate skader, mens dyrene i den ene gruppen for det meste hadde dødelige skader. Denne gruppen inneholdt dyr som små reker og eremittkreps. Eventuelle endringer i bunnsedimenter antas å være den viktigste faktoren for restituering av haneskjellfelt etter fangstoperasjoner siden dette kan endre forutsetningene og nyetablering samt levevilkårene for bunndyr. Påvirkningen av Harvester på bunnsedimentene så ut til å være svært moderate. Videoopptakene indikerte at en del finkornet sediment så ut til å være borte etter at Harvester hadde gått over området. En svakhet med denne undersøkelsen var at intensiteten i fangstingen ved forsøket med Harvester på langt nær var på det nivået en kan forvente ved et ordinært fiskeri. Vi undersøkte heller ikke hvor stor total biomasse av haneskjell og andre bunndyr som ble tatt ut med Harvester. Det anbefales derfor at det gjennomføres nye undersøkelser av påvirkningen på bunnfauna og sediment etter at et eventuelt fiskeri er kommet i gang.publishedVersio

Norwegian fisheries in the Svalbard zone since 1980. Regulations, profitability and warming waters affect landings

-The Svalbard archipelago in the High Arctic is influenced by cold Arctic water masses from the north-east and the warm West Spitsbergen Current flowing northwards along its western coast. The eastern waters and the fjords are normally frozen during the winter months, while the coastal waters west of the archipelago remain open. Norwegian fishers have been harvesting from Svalbard waters for decades and detailed records of catches exists from 1980 onwards. We analyze the catch records from the Svalbard zone (approximately ICES area IIb). The large fishery for capelin in summer yielding annual catches up to 737 000 tons was closed by a Norwegian fishery regulation in the mid nineteen nineties. Demersal fisheries have been continuous, and the results clearly indicate a northward trend in landings of Northeast Arctic cod, haddock, ling and Atlantic halibut. Fisheries of Northern shrimp have been more variable and shown no clear geographic trends. A “gold rush” fishery for scallops north of Svalbard lasted for about 10 years (1986–1995) only, and ended due to low profitably. These results are discussed in relation to the possibility of further northward extension of fisheries subjected to climate change

Highly mixed impacts of near-future climate change on stock productivity proxies in the North East Atlantic

Impacts of climate change on ocean productivity sustaining world fisheries are predominantly negative but vary greatly among regions. We assessed how 39 fisheries resources—ranging from data-poor to data-rich stocks—in the North East Atlantic are most likely affected under the intermediate climate emission scenario RCP4.5 towards 2050. This region is one of the most productive waters in the world but subjected to pronounced climate change, especially in the northernmost part. In this climate impact assessment, we applied a hybrid solution combining expert opinions (scorings)—supported by an extensive literature review—with mechanistic approaches, considering stocks in three different large marine ecosystems, the North, Norwegian and Barents Seas. This approach enabled calculation of the directional effect as a function of climate exposure and sensitivity attributes (life-history schedules), focusing on local stocks (conspecifics) across latitudes rather than the species in general. The resulting synopsis (50–82°N) contributes substantially to global assessments of major fisheries (FAO, The State of World Fisheries and Aquaculture, 2020), complementing related studies off northeast United States (35–45°N) (Hare et al., PLoS One, 2016, 11, e0146756) and Portugal (37–42°N) (Bueno-Pardo et al., Scientific Reports, 2021, 11, 2958). Contrary to prevailing fisheries forecasts elsewhere, we found that most assessed stocks respond positively. However, the underlying, extensive environmental clines implied that North East Atlantic stocks will develop entirely different depending upon the encountered stressors: cold-temperate stocks at the southern and Arctic stocks at the northern fringes appeared severely negatively impacted, whereas warm-temperate stocks expanding from south were found to do well along with cold-temperate stocks currently inhabiting below-optimal temperatures in the northern subregion.publishedVersio

Author Correction:Study of 300,486 individuals identifies 148 independent genetic loci influencing general cognitive function

Christina M. Lill, who contributed to analysis of data, was inadvertently omitted from the author list in the originally published version of this article. This has now been corrected in both the PDF and HTML versions of the article

Joint report for 2000 on the red king crab (Paralithodes camtschaticus) investigations in the Barents Sea

The present mean estimates of legal males above 150 mm CW in REZ and NEZ are 1 513 000 and 676 000 respectively. Estimates of total stock with CL > 60 mm in REZ are 12 546 000. There are no such estimates in NEZ. In NEZ the relative abundance of pre-recruits (115 mm< CL <132 mm) has increased from 6.5 % in 1999 to ca 25 % in 2000, indicating good recruitment to legal size stock within the next couple of years. The stock estimate of egg-carrying females in 2000 was 1 576 490 in NEZ and 693 888 in REZ. The surveys in 2000 revealed only minor recruitment to the crab stock in the Barents Sea. Moulting frequency of pre-recruits in NEZ and in REZ are high in 2000: 83 % and 95.6%, respectively. There are no signs of any effects of the one sex harvest strategy on the sex ratio in the crab stock. The crabs in NEZ are still inhabiting new areas along the coast of Finnmark and new parts of the coast will soon be of interest for fishery. The crab density is increasing in eastward in REZ. The crabs in the NEZ show only minor migrations. In Varanger there is mainly a westwards migration. Bycatch of king crabs is a major problem in the gillnet and longline fishery in the eastern Finnmark. In 1999 ca 120000 crabs were estimated caught as bycatch in the gillnet fishery for cod alone in NEZ and 30 000 crabs in the trawl fishery for whitefish in REZ. Several regulations are given for commercial fishery conserning a possible opening of a aiming to improve the management of the king crab in the Barents Sea are proposed.Joint report for 2000 on the red king crab (Paralithodes camtschaticus) investigations in the Barents SeapublishedVersio

Bycatch in trawl-fisheries. Sub-project 3

The main goals of this sub-project were to evaluate whether interviewing fishers could be an appropriate method to reveal quantities of the bycatches in the Norwegian trawl fisheries, and to describe the knowledge about and the fishermen's attitudes to the bycatch problem. In total 11 crew members on trawlers from a fishing company in Lofoten were interviewed. The data from the interviews showed that the trawl fishermen had very little focus on bycatch as we defined it, and the interviews gave only partly information on reliable quantities of the different species. Interviews are a good method revealing the fisher’s knowledge, norms and attitudes, but should be accompanied by practical recordings when it comes to quantitative estimates. No differences in the attitudes to bycatch were found between officers and fishers among the informants. But there seem to be a difference both in knowledge of species and the attitude to exploitation of bycatch, between fishers with experience from the coastal fishery and those with a strict trawl fishery career. The shipping companies are much more crucial in defining the premises for a future exploitation of the bycatch in the trawl fishery than the fishermen onboard the trawlers.Bycatch in trawl-fisheries. Sub-project 3publishedVersio

Bifangst av kongekrabbe i garn-og linefisket i 1999

I alt 16 fiskere har registrert bifangst av kongekrabbe ved eget fiske med torskegarn, rognkjeksgarn og line i området Varanger – Nordkapp gjennom hele 1999. Dette er noe færre enn i 1998. Resultatene viser at problemene med bifangst fortsatt er størst i Varanger, men at problemet er i ferd med å tilta også i andre områder. Estimert bifangst av krabbe i torskegarn i 1999 var ca 121 000 stk., mens estimatene på line (ca. 11.000) var betydelig lavere. Dette er en økning i forhold til undersøkelsen i 1999. Det er for det meste hunnkrabbe som tas som bifangst, sammen med mye undermåls krabbe. Tidligere undersøkelser indikerer at dødeligheten av krabben som tas på garn er nærmere 100 %, mens de som tas på line har større mulighet til å overleve siden de blir mindre skadet. Undersøkelsen er gjennomført i nært samarbeid med lokale fiskerimyndigheter i Finnmark.Bifangst av kongekrabbe i garn-og linefisket i 1999publishedVersio