Jellyfish blooms are common in many oceans, and anthropogenic changes appear to have increased their magnitude in some regions. Although mass falls of jellyfish carcasses have been observed recently ...at the deep seafloor, the dense necrophage aggregations and rapid consumption rates typical for vertebrate carrion have not been documented. This has led to a paradigm of limited energy transfer to higher trophic levels at jelly falls relative to vertebrate organic falls. We show from baited camera deployments in the Norwegian deep sea that dense aggregations of deep-sea scavengers (more than 1000 animals at peak densities) can rapidly form at jellyfish baits and consume entire jellyfish carcasses in 2.5 h. We also show that scavenging rates on jellyfish are not significantly different from fish carrion of similar mass, and reveal that scavenging communities typical for the NE Atlantic bathyal zone, including the Atlantic hagfish, galatheid crabs, decapod shrimp and lyssianasid amphipods, consume both types of carcasses. These rapid jellyfish carrion consumption rates suggest that the contribution of gelatinous material to organic fluxes may be seriously underestimated in some regions, because jelly falls may disappear much more rapidly than previously thought. Our results also demonstrate that the energy contained in gelatinous carrion can be efficiently incorporated into large numbers of deep-sea scavengers and food webs, lessening the expected impacts (e.g. smothering of the seafloor) of enhanced jellyfish production on deep-sea ecosystems and pelagic–benthic coupling.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
Careful definition and illustrative case studies are fundamental work in developing a Blue Economy. As blue research expands with the world increasingly understanding its importance, policy makers ...and research institutions worldwide concerned with ocean and coastal regions are demanding further and improved analysis of the Blue Economy. Particularly, in terms of the management connotation, data access, monitoring, and product development, countries are making decisions according to their own needs. As a consequence of this lack of consensus, further dialogue including this cases analysis of the blue economy is even more necessary. This paper consists of four chapters: (I) Understanding the concept of Blue Economy, (II) Defining Blue economy theoretical cases, (III) Introducing Blue economy application cases and (Ⅳ) Providing an outlook for the future. Chapter (II) and Chapter (III) summarizes all the case studies into nine aspects, each aiming to represent different aspects of the blue economy. This paper is a result of knowledge and experience collected from across the global ocean observing community, and is only made possible with encouragement, support and help of all members. Despite the blue economy being a relatively new concept, we have demonstrated our promising exploration in a number of areas. We put forward proposals for the development of the blue economy, including shouldering global responsibilities to protect marine ecological environment, strengthening international communication and sharing development achievements, and promoting the establishment of global blue partnerships. However, there is clearly much room for further development in terms of the scope and depth of our collective understanding and analysis.
To quantify how fish farming modifies short-term benthic carbon cycling in fjord environments and the role of hydrodynamics in modifying effects on the benthos, we assessed benthic ecosystem ...structure and respiration and used isotope labeled algae as a tracer to quantify C flow over 48 h through macrofauna and bacteria in sediments collected from beneath fish farm sites in (1) high water-flow areas, (2) low water-flow areas, and (3) two appropriate control sites situated downstream from the farms. Bacterial biomass was significantly greater in sediments collected from the fish farm sites relative to the controls. This was also true for sediment oxygen consumption (SOC) rates averaged over each 48 h investigation, which were significantly correlated with total benthic (macrofauna and bacteria) biomass. Short-term C-uptake rates by macrofauna were elevated in both fish farm treatments compared with bacterial C uptake and were significantly higher in sediments from the low flow fish farm site relative to both controls. While SOC rates were significantly higher in experiments using sediments from the low flow fish farm site; faunal abundance, biomass uptake, C uptake, bacterial biomass, and metabolism in sediments from both fish farm treatments were not significantly different from one another. Fish farming can dramatically alter benthic ecosystem functioning, and significant effects can occur around fish farms irrespective of the water-flow regime the farms are moored in.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NMLJ, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
How do e-scooters impact accessibility in urban areas for people with visual impairment or impaired mobility? We conducted two surveys among members of the Norwegian Association of the Blind and ...Partially Sighted and the Norwegian Association of Disabled. Results show that many are hindered by parked e-scooters, particularly on sidewalks, and most feel unsafe when interacting with e-scooter riders. More than half use more time on trips in urban areas due to e-scooters, while some avoid specific areas or even whole trips. Feeling unsafe and experiencing e-scooters as obstacles is associated with needing more time on trips or avoiding areas/trips.
Sustainable development of the salmon farming industry requires knowledge of the biogeochemical impacts of fish farm emissions. To investigate the spatial and temporal scales of farm impacts on the ...water column and benthic biogeochemistry, we coupled the C-N-P-Si-O-S-Mn-Fe transformation model BROM with a 2-dimensional benthic-pelagic transport model (2DBP), considering vertical and horizontal transport in the water and upper 5 cm of sediments along a 10 km transect centered on a fish farm. The 2DBP model was forced by hydrophysical model data for the Hardangerfjord in western Norway. Model simulations showed reasonable agreement with field data from the Hardangerfjord in August 2016 (correlations between the model and observations were significant for most variables, and model biases were mostly <35%). The model predicted significant impacts on seafloor biogeochemistry up to 1 km from the fish farm (e.g., increased organic matter in sediments, oxygen depletion in bottom water and sediments, denitrification, metal and sulfur reduction), as well as detectable decreases in oxygen and increases in ammonium, phosphate and organic matter in the surface water near to the fish farm.
The effects of carbon dioxide (CO
2(aq)) on gonad growth and feed intake in green sea urchin,
Strongylocentrotus droebachiensis, were examined. Adult sea urchins with a mean (S.D.) live weight of ...50.0 (11.2) g were exposed to two levels of carbon dioxide (CO
2(aq)), (1.1 (control) and 18.1 mg l
−
1
), for 56 days at 6.0 °C and 33‰.
Gonad growth was significantly reduced in the high CO
2 concentration group compared to the control group. In the high carbon dioxide treatment, gonad growth was 67% less than the control treatment. Weekly feed intake and total feed consumption were significantly reduced in the high concentration group. The reduction in gonad growth was attributed to a decrease in feed intake and impaired feed conversion efficiency. The present study demonstrates that adult green sea urchins show low tolerance to increased carbon dioxide levels, and are unable to maintain high gonad growth facing such conditions.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
‘Offshore’ aquaculture has gained increased attention as a potential route of expanding production of commercially important finfish species such as Atlantic salmon (Salmo salar). However, there is a ...lack of clarity about the term ‘offshore’ and how different ‘offshore’ environments are, compared to more traditional coastal or inshore locations. This uncertainty is an issue for effective governance and regulation and is a bottleneck for development that must be addressed. This study used a mixed method approach to evaluate what is meant by ‘offshore’ production and determine if existing approaches are suitable for licensing and regulating ‘offshore’ salmon aquaculture in Scotland, as a case study. First, a systematic literature review was used to assess academic studies and then an online questionnaire was used to gather views from salmon aquaculture stakeholders in Scotland and other countries. The results show there is inconsistency in what is perceived by the term ‘offshore’ aquaculture, making it challenging to determine a global definition. Literature, which was not limited to salmon production, tended to focus on distance from the coast but salmon aquaculture stakeholders had very mixed views, though a slight majority considered wave exposure was the key characteristic. The stakeholders indicated there may be a number of benefits of ‘offshore’ salmon aquaculture, but also suggested that existing regulations are not appropriate for ‘offshore’ salmon production and could be enhanced. The study results suggest that regulators and stakeholders need to agree on consistent terminology that characterises the production environment. Depending on local or regional complexities, several classifications that reflect key features, may be required. Additionally, new or adapted approaches to aquaculture licensing, regulation and site suitability may also be needed to account for physical and ecological differences from more traditional farming locations. Ultimately, environmental regulation will only be fit-for-purpose if it is evidence-based and relevant to the environmental conditions, surrounding ecosystem, and species being produced. Ironically, the biggest constraint to ‘offshore’ aquaculture regulation seems be understanding what ‘offshore’ is and means, and until this is addressed there will continue to be uncertainty and confusion that hinders development of the sector.
•Regulation is a bottleneck that is limiting expansion of ‘offshore’ aquaculture•Inconsistency in how ‘offshore’ aquaculture is defined is creating confusion and uncertainty•‘Offshore’ regulation must be relevant to the environment, species, and production method
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Commercial farming of Atlantic cod (Gadus morhua L.) is now being developed in several countries. The ecological consequences of cod culture are poorly understood, but recent research suggests that ...Atlantic cod are more prone to escape from net pens than Atlantic salmon. Here, we describe the movements and the spatiotemporal distribution of farmed cod after escape relative to wild cod, both during and outside the natural spawning season. The experimental design included simulating escape incidents of farmed cod tagged with acoustic transmitters and using an array of automatic listening stations to monitor their dispersal and distribution. For comparison, local wild cod were monitored using the same array of receivers. The farmed cod dispersed rapidly after a simulated escape, they randomly distributed over large areas and their distribution overlapped with local wild cod. Moreover, escaped farmed fish were found at local cod spawning areas during the spawning season. The study also indicated that the recapture rate of escaped farmed cod was high compared with that of escaped farmed salmon. Thus, while our results showed that there is a considerable potential for ecosystem effects caused by escaped farmed cod, mitigating actions such as an efficient recapture fishery for escapees may be possible.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Recently there has been increased interest in species diversification in aquaculture as a strategy to adapt to climate change. Since species diversification is a long-term strategy, climate change ...and future farming conditions must be considered. The aim of this study was to evaluate how changing temperatures under different IPCC climate scenarios may affect marine aquaculture species diversification in Norway. Since farm conditions vary between locations, this study focused on four geographic areas (South, West, North and Arctic) and three farms within each area. Using a climate model downscaling of three climate scenarios (Shared Socioeconomic Pathways; SSP1–2.6, SSP2–4.5, and SSP5–8.5), daily temperatures from the years 2020–2099 were evaluated at each farm location to identify challenging conditions for 34 species. A Challenging Conditions Index (CCI) was developed based on species thermal tolerances to compare the 34 potential aquaculture species. The results showed differences in the number of challenging days (hot and cold) between areas, and even within areas, highlighting the need to consider site-specific conditions. For warm-water species more commonly farmed in the Mediterranean (e.g. European seabass, gilthead seabream), the calibrated model projections at the investigated Norwegian farm sites suggest that cold temperatures would still be challenging. Differences in the number of challenging days between the climate scenarios become more apparent towards the mid and end of century, though all scenarios show interannual variation rather than a constant change in conditions over time. Hence, any species selected for diversification purposes will have to be able to tolerate a range of temperature conditions, and species with narrower tolerance ranges could be a risk. These findings underline the importance of considering the interannually varying conditions that species will be exposed to rather than focusing solely on long-term averages. Establishing a new large-scale commercial aquaculture species takes a considerable amount of time and resources. Therefore, to support interpretation of the results and further studies on diversification under climate change, this study also introduces Aquaculture Readiness Level (ARL®) as a consistent evaluation of the research and development status, progress towards commercialisation and climate action orientated production. As species will have to be able to tolerate a range of temperature conditions over different years, the level of knowledge, resources, and innovation will have to be continually enhanced to improve adaptive capacity.
•Climate change will affect aquaculture diversification in Norway.•Considered 34 species, 12 farms in 4 regions, 3 climate scenarios over 80 years.•Challenging Conditions Index was developed to describe different levels of challenges.•Future aquaculture candidates must tolerate a range of temperature conditions.•Aquaculture Readiness Levels embed climate action at the heart of diversification.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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