Water type quantification in the Skagerrak, the Kattegat and off the Jutland west coast

SummaryAn extensive data series of salinity, nutrients and coloured dissolved organic material (CDOM) was collected in the Skagerrak, the northern part of the Kattegat and off the Jutland west coast in April each year during the period 1996–2000, by the Institute of Marine Research in Norway. In this month, after the spring bloom, German Bight Water differs from its surrounding waters by a higher nitrate content and higher nitrate/phosphate and nitrate/silicate ratios. The spreading of this water type into the Skagerrak is of special interest with regard to toxic algal blooms. The quantification of the spatial distributions of the different water types required the development of a new algorithm for the area containing the Norwegian Coastal Current, while an earlier Danish algorithm was applied for the rest of the area. From the upper 50m a total of 2227 observations of salinity and CDOM content have been used to calculate the mean concentration of water from the German Bight, the North Sea (Atlantic water), the Baltic Sea and Norwegian rivers. The Atlantic Water was the dominant water type, with a mean concentration of 79%, German Bight Water constituted 11%, Baltic Water 8%, and Norwegian River Water 2%. At the surface the mean percentages of these water types were found to be 68%, 15%, 15%, and 3%, respectively. Within the northern part of the Skagerrak, closer to the Norwegian coast, the surface waters were estimated to consist of 74% Atlantic Water, 20% Baltic Water, and 7% Norwegian River Water. The analysis indicates that the content of German Bight Water in this part is less than 5%

Release of artificially reared 0-group coastal cod (Gadus morhua L.) in a landlocked fjord in western Norway

In 1983 and 1984 about 14 000 seven month old pond or basin reared coastal cod were tagged and released in Heimarkspollen and Osen in Western Norway. In May 1984 fishing in the release areas was initiated and local fishermen were asked to report recaptures. Growth of released cod was at least as good as growth of wild cod in the area. The 1983 release contributed about 30% of this yearclass in Osen and about 50% in Heimarkspollen. The 1984 release contributed about 80% of this yearclass in Heimarkspollen. There seems to be no difference in food preference between released and wild cod. The reared cod are very stationary

Nasjonale Beredskapsressurser: Hvordan legge til rette for samhandling i midlertidige strukturer

Denne studien undersøker hvordan politiets nasjonale beredskapsressurser (NB) kan legge til rette for samhandling i midlertidige strukturer. Slike midlertidige strukturer etableres når ressurser fra NB samhandler med eksterne aktører i løsning av særlig farlige og komplekse hendelser. NB eier ingen oppdrag selv men har en definert rolle i løsning av oppdrag i hele Norge. Som bistandsorgan er enheten dermed avhengig av andre som premissleverandør i hendelseshåndteringen. For å belyse problemstilingen ble det utledet tre forskningsspørsmål. Det første skulle undersøke relevante samhandlingsaktørers forventninger til NB. De to andre spørsmålene undersøkte hvordan mellommenneskelige faktorer og strukturelle element kunne gi postitiv effekt i samhandling. Datainnsamlingen ble utført som semistrukturerte kvalitative intervju. Det ble gjennomført 12 intervju av ledere på taktisk og operasjonelt nivå i fem forskjellige politidistrikt. En tematisk analysen av datamaterialet ga en oversikt over informantenes forventninger til NBs leveranser. NB bør fokusere på en kunnskapsbasert utvikling innenfor sine ansvarsområder, være tilgjengelig for andre i trening og øvelser, raskt kunne tilby faglig rådgiving og bistå med komplementær innsats i selve hendelsehåndteringen når situasjonen krever det. Dette samsvarer med NBs oppgaveportefølje beskrevet i styrende dokumenter og definerer premisset for når NB må samhandle. På bakgrunn av datamaterialet og påfølgende drøfting av funn ble det utledet hvordan NB kan legge til rette for god samhandling. Sosial interaksjon gir premissene for samhandling. I denne interaksjonen skapes relasjoner, som igjen skaper trygghet og tillit. En inkluderende tilnærming til samhandlingsaktører fører til involvering og eierskap hos alle parter. Slik får man brukt alle ressursene på rett måte til rett tid. NB må videre forhindre at det skapes usikkerhet i samhandlingen da dette kan hemme innsatsevnen. Strukturer gir kapasitet og overskudd. Likhet i tilnærming skaper forventninger, tydeliggjør roller og ansvar og frigir dermed kapasitet. Deltagelse på arenaer i forkant av hendelser legger til rette for sosial interaksjon og skaper relasjoner. I selve hendelsehåndteringen gir fysisk samlokalisering effekt i midlertidige team. Dette fører til hurtigere informasjonsflyt, raskere rolleavklaring, bedre koordinering og dermed bedre prestasjoner. Det er vekselvirkning mellom sosial interaksjon og strukturelle faktorer. Disse virker inn i alle faser av krisehåndteringen. Ved kontinuerlig fokus på disse faktorene kan NB tilrettelegge for god samhandling i midlertidige strukturer som etableres i løsning av kriser og uforusette hendelser

Kartlegging av gytefelter i Nordsjøen – Rapport fra KINO-prosjektet

Spawning areas and spawning periods of 34 North Sea fish species have been studied by combining data, models and literature. Major part of data is from eggs and larvae surveys. In addition, data from research vessels and commercial catches on mature (i.e. ripe and running fish) have been applied. A hydrodynamic model including particle-tracking algorithm was applied to trace the drift pattern from the spawning areas. Model results were compared with observations on larval distribution on some selected key species. Finally, a comprehensive literature has been synthesized to include all additional knowledge on spawning activity, and eggs and larval distributions. The literature study revealed that the changing climate over the recent 50 years has influenced distribution of fish stocks and their spawning areas.Gyteområder og gyteperioder for 34 fiskearter i Nordsjøen er undersøkt ved kombinert utnyttelse av data, modell og litteratur. Hoveddelen av datatilfanget er fra egg- og larvesurvey. I tillegg er det benyttet data for gytende fisk fra både forskningsfangster og kommersielle fangster. En hydrodynamisk modell med partikkelsporing ble benyttet til å modellere drift av egg og larver fra sentrale gytefelter for utvalgte nøkkelarter og å sammenligne modellresultatene med observasjoner for egg og larver. Til slutt er en omfattende mengde litteratur for gyteadferd, egg og larver syntetisert. Litteraturstudien viste at klimaendringene over de siste 50 år har påvirket fordeling av mange av fiskebestandene, herunder gytefeltene

Declining size-at-harvest in Norwegian salmon aquaculture: Lice, disease, and the role of stunboats

Sea cages used for fish farming are typically open to the environment, making the grow-out phase a race against the accumulation of infections. In Norway, farmed Atlantic salmon (Salmo salar) suffer outbreaks of salmon lice (Lepeophtheirus salmonis), which by law must be managed, and comorbid infections that weaken salmon and increase the risk of mortality following delousing treatments. To understand the role of louse management on size-at-harvest, we analysed monthly data from 1054 salmon farms over a 10-year period. Mean weight at harvest declined 6.6% (−310 g) from 2012 to 2021, with the smallest size-at-harvest occurring in months when delousing treatments were reported. In 2021, size-at-harvest was 3.4% smaller during treatment vs. non-treatment months. There is a pattern of increasing responsiveness to louse outbreaks over time, with delousing treatments preferred for small fish and harvesting preferred for large fish. There are also several lines of evidence suggesting that potential post-treatment mortalities are sometimes diverted to harvest statistics. Treatments tend to lead to higher relative mortality in the following month, except when a harvest was also reported during the treatment month. Stunboats are harvesting vessels equipped with stunning, bleeding and chilling systems, and anecdotally, are preferred for ‘emergency’ harvests. We found that stunboat visits were disproportionately associated with harvests of small fish during 2018–2021. Moreover, stunboats often visited during treatment months without any harvest being reported, consistent with accounts of stunboats standing by during risky operations to salvage moribund fish if necessary. Because harvests and mortalities are reported monthly, it is not clear how often harvests during treatment months reflect (i) harvesting of vulnerable fish as an alternative to treating, or (ii) risky treatments that produce moribund fish. However, if the latter is common, mortality statistics will underestimate the health and welfare risks of delousing treatments.publishedVersio

Forecasted Shifts in Thermal Habitat for Cod Species in the Northwest Atlantic and Eastern Canadian Arctic

Climate change will alter ecosystems and impose hardships on marine resource users as fish assemblages redistribute to habitats that meet their physiological requirements. Marine gadids represent some of the most ecologically and socio-economically important species in the North Atlantic, but face an uncertain future in the wake of rising ocean temperatures. We applied CMIP5 ocean temperature projections to egg survival and juvenile growth models of three northwest Atlantic coastal species of gadids (Atlantic cod, Polar cod, and Greenland cod), each with different thermal affinities and life histories. We illustrate how physiologically based species distribution models (SDMs) can be used to predict habitat distribution shifts and compare vulnerabilities of species and life stages with changing ocean conditions. We also derived an integrated habitat suitability index from the combined surfaces of each metric to predict areas and periods where thermal conditions were suitable for both life stages. Suitable thermal habitat shifted poleward for the juvenile life stages of all three species, but the area remaining differed across species and life stages through time. Arctic specialists like Polar cod are predicted to experience reductions in suitable juvenile habitat based on metrics of egg survival and growth potential. In contrast, habitat loss in boreal and subarctic species like Atlantic cod and Greenland cod may be dampened due to increases in suitable egg survival habitats as suitable juvenile growth potential habitats decrease. These results emphasize the need for mechanistic SDMs that can account for the combined effects of changing seasonal thermal requirements under varying climate change scenarios.publishedVersio

Matrix metalloproteinase-9 mediated shedding of syndecan-4 in glomerular endothelial cells

Background - Diabetic nephropathy is the most common cause of end‐stage renal failure in the western world and Asia. The mechanisms are not fully elucidated, but disruption of glomerular endothelial glycocalyx and shedding of its components including syndecans has been implicated. Aims - We hypothesize that reduced glomerular filtration in diabetes is caused by disruption of endothelial glycocalyx in glomeruli, including increased shedding of syndecan‐4. The aim of this study was to determine the effects of experimental diabetic conditions by means of hyperglycemia and IL‐1β exposure on syndecan‐4 shedding in GEnC, and to investigate regulation of shedding by sheddases. Results - We found that in GEnC the expression of syndecan‐4 is higher than that of the other syndecans. In polarized GEnC, apical shedding of syndecan‐4 and syndecan‐4 gene expression was increased by 60% after IL‐1β‐stimulation, but not affected by hyperglycemic conditions. This was accompanied by a 50% increase in MMP9 gene expression in IL‐1β‐stimulated cells but not hyperglycemia. MMP9 knockdown reduced syndecan‐4 shedding by 50%. Conclusion - IL‐1β but not hyperglycemia increases the shedding of syndecan‐4 from GEnC in an MMP9‐dependent manner. This provides a potential mechanism of GEnC damage in diabetes and other inflammatory conditions

Modeled Buoyancy of eggs and larvae of the deep-sea shrimp Aristeus antennatus (Crustacea: Decapoda) in the northwestern Mediterranean Sea

Information on the buoyancy of eggs and larvae from deep-sea species is rare but necessary for 30 explaining the position of non-swimming larvae in the water column. Due to embryonic 31 morphology and ecology diversities, egg buoyancy has important variations within one species and 32 among other ones. Nevertheless, it has hardly been explored if this buoyancy variability can be a 33 strategy for deep-sea larvae to optimize their transport beyond their spawning areas. In the 34 northwestern Mediterranean Sea, protozoea and mysis larvae of the commercial deep-sea shrimp 35 Aristeus antennatus were recently found in upper layers, but to present, earlier stages like eggs and 36 nauplii have not been collected. Using a Lagrangian transport model and larval characteristics, we 37 evaluate the buoyancy and hydrodynamic effects on the transport of A. antennatus larvae in the 38 northwestern Mediterranean Sea. The transport models suggested that 75% of buoyant eggs 39 released between 500 and 800 m depth (i.e., known spawning area), reached the upper water layers 40 (0-75 m depth). Then, according to the modeled larval drifts, three spawning regions were defined 41 in the studied area: 1) the northern part, along a continental margin crossed by large submarine 42 canyons; 2) the central part, with two circular circulation structures (i.e., eddies); and 3) the 43 southern part, with currents flowing through a channel. The number of larvae in the most upper 44 layer (0-5 m depth) was higher if the larval transport model accounted for the ascent of eggs and 45 nauplii (81%) instead of eggs reaching the surface before hatching (50%). The larvae reaching the 46 most water upper layer (0-5 m depth) had higher rates of dispersal than the ones transported below 47 the surface layer (deeper than 5 m depth). The results of larval dispersal simulations have 48 implications for the understanding of A. antennatus larval ecology and for management decisions 49 related to the shrimp fisheries in the northwestern Mediterranean S

Matrix metalloproteinase-9 mediated shedding of syndecan-4 in glomerular endothelial cells

Background - Diabetic nephropathy is the most common cause of end‐stage renal failure in the western world and Asia. The mechanisms are not fully elucidated, but disruption of glomerular endothelial glycocalyx and shedding of its components including syndecans has been implicated. Aims - We hypothesize that reduced glomerular filtration in diabetes is caused by disruption of endothelial glycocalyx in glomeruli, including increased shedding of syndecan‐4. The aim of this study was to determine the effects of experimental diabetic conditions by means of hyperglycemia and IL‐1β exposure on syndecan‐4 shedding in GEnC, and to investigate regulation of shedding by sheddases. Results - We found that in GEnC the expression of syndecan‐4 is higher than that of the other syndecans. In polarized GEnC, apical shedding of syndecan‐4 and syndecan‐4 gene expression was increased by 60% after IL‐1β‐stimulation, but not affected by hyperglycemic conditions. This was accompanied by a 50% increase in MMP9 gene expression in IL‐1β‐stimulated cells but not hyperglycemia. MMP9 knockdown reduced syndecan‐4 shedding by 50%. Conclusion - IL‐1β but not hyperglycemia increases the shedding of syndecan‐4 from GEnC in an MMP9‐dependent manner. This provides a potential mechanism of GEnC damage in diabetes and other inflammatory conditions

Carbon export is facilitated by sea urchins transforming kelp detritus

With the increasing imperative for societies to act to curb climate change by increasing carbon stores and sinks, it has become critical to understand how organic carbon is produced, released, transformed, transported, and sequestered within and across ecosystems. In freshwater and open-ocean systems, shredders play a significant and well-known role in transforming and mobilizing carbon, but their role in the carbon cycle of coastal ecosystems is largely unknown. Marine plants such as kelps produce vast amounts of detritus, which can be captured and consumed by shedders as it traverses the seafloor. We measured capture and consumption rates of kelp detritus by sea urchins across four sampling periods and over a range of kelp detritus production rates and sea urchin densities, in northern Norway. When sea urchin densities exceeded 4 m−2, the sea urchins captured and consumed a high percentage (ca. 80%) of kelp detritus on shallow reefs. We calculated that between 1.3 and 10.8 kg of kelp m−2 are shredded annually from these reefs. We used a hydrodynamic dispersal model to show that transformation of kelp blades to sea urchin feces increased its export distance fourfold. Our findings show that sea urchins can accelerate and extend the export of carbon to neighboring areas. This collector–shredder pathway could represent a significant flow of small particulate carbon from kelp forests to deep-sea areas, where it can subsidize benthic communities or contribute to the global carbon sink