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Status of individual animals is often shown in pigmentation. For instance, stress responsiveness is associated with melanin-based pigmentation in vertebrates in general. This pattern is evident in Atlantic salmon ( Salmo salar ) and rainbow trout ( Oncorhynchus mykiss ), with melanin-based spots indicating stress coping style. Arctic char ( Salvelinus alpinus ) differ from other salmonids in pigmentation but have an association between carotenoid-based pigmentation and stress coping style. These pigmentation differences could be used as a fast and simple tool for improving breeding programs. However, the procedure for photographing individuals is stressful. Therefore, we wanted to investigate if 3 common inhalation anesthetics could be used to reduce the stress involved in the procedure compared to a no-anesthetics group. Behavior was also monitored during the anesthetization. All 3 anesthetics (Aquacalm, Benzocaine, and MS-222) differed in pigmentation compared to the no-anesthetics group by having a higher number of spots. In the anesthetic treatments as well as the no-anesthetics group, the fish had elevated plasma cortisol levels. In fact, the no-anesthetics group had higher cortisol than treated fish. This was probably because of procedural differences such as time affecting the stress response. Furthermore, in a long-term experiment, all fish survived and had similar condition factors 1 week after photographing as before. Therefore, the method for photographing Arctic char is deemed safe and could be used as a tool for estimating stress coping style, but careful planning is needed for experiments using it.

The report summarises the monitoring activities within the National Swedish Contaminant Programme for freshwater biota. Each monitored contaminant has been examined in pike, perch or Arctic char from 32 lakes from the north to the south in Sweden. No general trend could be seen for mercury, and all samples were above the EU threshold. Lead was generally decreasing. Cadmium concentrations showed no consistent trends over the monitored period, and cadmium concentrations in 2017 were below the suggested threshold in all lakes. Nickel showed a general upward trend in 30% of the perch lakes. Arsenic concentrations showed no general spatial pattern and were increasing in liver from Arctic char, pike and perch from approximately 50 % of the sampling sites. Tin concentrations decreased in the majority of the perch time series during the most recent ten years. For copper, no general spatial pattern existed for concentrations in perch and about one third of the monitored lakes showed an upward trend. No general trend was observed for silver and aluminum. In general, downward trends were seen for; PCBs, HCHs, DDT, DDE and PCDD/Fs in all species (with a few exceptions). The chlorinated compounds generally showed a somewhat higher concentration in the southern parts of Sweden. Most chlorinated compounds were below the suggested target levels. No general trend was seen during the monitoring period for PBDEs. However an indication of decreasing concentrations of PBDEs is seen in the most recent years. The concentration of HBCDD was under LOQ in a majority of the samples. Several of the perfluorinated carboxylic compounds showed an increase in concentration in arctic char, while PFOS and FOSA decreased. In perch PFOS has decreased since 1995. Higher concentrations of perfluorinated compounds can in general be seen in the southern part of Sweden. In all lakes, PFOS is below the target level for all species.

The report summarises the monitoring activities within the National Swedish Contaminant Programme for freshwater biota. Each monitored contaminant has been examined in pike, perch or Arctic char from 32 lakes from the north to the south in Sweden. No general trend could be seen for mercury, and all samples, except Arctic char from Abiskojaure, were above the EU target level. Lead was generally decreasing. Nickel showed a general upward trend in perch. An increase, or indication of an increase, was seen for chromium during the last ten years. Zinc concentrations were decreasing in a majority of the perch samples and in pike from Lake Storvindeln. No general trend was observed for copper, arsenic, silver, aluminum, tin, bismuth, and cadmium. In general, downward trends were seen for; PCBs, HCHs, DDT, DDE and PCDD/Fs in all species (with a few exceptions). The chlorinated compounds generally show a somewhat higher concentration in the southern parts of Sweden. Most chlorinated compounds were below the suggested target levels. No general trend was seen during the monitoring period for PBDEs. Concentrations of PBDEs in Lake Bolmen increased from the 60s and peaked in the late 80s to mid-90s and have subsequently decreased. The concentration of HBCDD was under LOQ in a majority of the samples. Several of the perfluorinated carboxylate compounds showed an increase in concentration in perch, while PFOS and FOSA decreased. Higher concentrations of perfluorinated compounds can in general be seen in the southern part of Sweden. In all lakes, PFOS is below the target level for all species.

The report summarises the monitoring activities within the National Swedish Contaminant Programme for freshwater biota. Each monitored contaminant has been examined in pike, perch and Arctic char from 32 lakes from the north to the south in Sweden. No general trend could be seen for mercury, and all samples, except Arctic char from Abiskojaure, were above the EU target level. Lead was generally decreasing. Nickel showed a general upward trend in perch. An increase, or indication of an increase, was seen for chromium during the last ten years. Zinc concentrations were decreasing in a majority of the perch samples and in pike from Lake Storvindeln. No general trend was observed for copper, arsenic, silver, aluminum, tin, bismuth, and cadmium. In general, downward trends were seen for; PCBs, HCHs, DDT, DDE and PCDD/Fs in all species (with a few exceptions). The chlorinated compounds generally show a somewhat higher concentration in the southern parts of Sweden. Most chlorinated compounds were below the suggested target levels. No general trend was seen during the monitoring period for PBDEs. Concentrations of PBDEs in Lake Bolmen increased from the 60s and peaked in the late 80s to mid-90s and have subsequently decreased. The concentration of HBCDD was under LOQ in a majority of the samples. A majority of the perfluorinated compounds showed an increase in concentration in perch, except PFOS and FOSA. Higher concentrations of perfluorinated compounds can in general be seen in the southern part of Sweden.

Resursövervakningen av sötvatten, RASKA, bygger dels på Fiskeriverkets egna undersökningar, men till stora delar också på sammanställning av uppgifter framtagna av andra myndigheter, organisationer och ideella föreningar. RASKA är således beroende av beredvilligheten hos andra att dela med sig av sin information. Vår förhoppning är att sammanställningen och syntesen skall ge mer information än de olika delarna var för sig och att vi därigenom kan ge en samlad överblick över ett större antal vatten tillbaka till de enskilda uppgiftslämnarna. Detta arbete sker gemensamt av Fiskeriverket och Laxforskningsinstitutet, LFI. Inom Fiskeriverket sker samordningen och dataläggningen vid Sötvattenslaboratoriet, Örebro, medan Fiskeriverkets utredningskontor och LFI svarar för dataleverans, materialanalys och syntesansvar vad gäller havsöring och lax. The present report gives the status of fishpopulations in inland waters and coastal rivers in Sweden. The stock data consist of electrofishing results, fish ladder counts, fishing statistics and stockings from rivers. From the four greatest lakes data consist of fisherystatistics, prey species abundances (hydroacoustics) and stockings. Anadromous salmon and trout on the Swedish west coast depend on liming. Salmon sea survival has declined. Added to these problems are increased occurrence of the parasite Gyrodactylus salaris and Danish experiments with delayed release of salmon in the southern Baltic. The latter has lead to increased contamination of natural spawningstocks with stocked salmon. The fishing on mixed salmon stocks must cease to improvethe number of spawners, especially in small populations. Brown trout stocks are stable. Due to overexploitation by the sea and coastal fishery, natural anadromous salmonin the Baltic were below acceptable levels,with increasing risk of genetic deteriorationand considerable economic losses. Due to reduced TAC (total allowable catch) and reduced effects of the M74 syndrome, causing excessive fry mortality, stocks are slowly increasing. The situation for anadromous browntrout in the Baltic is unclear, but several small stocks are too heavily exploited by gillnetting close to river mouths. Lake resident salmon occur naturally only in Lake Vänern, where the two remaining stocks have suffered heavily from the building of dams for hydroelectric purposes.The fishing is based on stocked fish, all without the adipose fin, while the few natural produced fish, i.e. with adipose fin left, are protected. Increased legal size together within creased closed areas are measures that have improved the conditions for the stocks in the last years, but both stocks must still be regarded as threatened. Trout populations in inland waters have generally increased during the last two decades. Liming, habitat restoration and increased closed areas are considered the most important measures for the stocks in the future. Approximately 200 commercial fishermen utilize the four great lakes (Vänern, Vättern, Mälaren, Hjälmaren). Detailed fishery statistics are collected on a monthly basis, including effort. In Lake Vänern salmon (’lax’) and trout (’öring’) together with whitefish (’sik’) and cisco (’siklöja’) dominate the catch. Roe from cisco contributes with approximately 50% of the catch value, but the population is presently declining. In Lake Vättern the catch is dominated by salmon, Arctic char (’röding’) and whitefish. Stocking of salmon, a new species in the lake, gives a high yield; 600-800 kg salmon/1,000 smolts released. Monitoring is carried out to study if the salmon stockings will have negative effects on the resident Arctic char, as the two species compete for the same prey species. In both lakes trolling for salmon and trout takes a large part of the total catch. In Lake Mälaren and Hjälmaren eel (’ål’) and zander (pikeperch, ’gös’) are important species. The eelfishery is completely dependent on stockings. In the former lake cisco was important until late 80’s, but then the population drastically declined, due to recruitment failure. The reason is not clear, but it coincides with warm winters with a short period with ice cover. The status of the crayfish (Astacus astacus) is given in chapter 7. The crayfish plague was spread from Finland to Sweden in 1907 and many populations of the native crayfish have been eradicated. The plague later was further spread due to introduction of the American crayfish (Pacifastacus leniusculus).Today Astacus astacus is considered an endangered species in southern Sweden, and restriction on stockings of the American crayfish has been imposed. Due to the membership in EU the threat to the native species has increased as import of live exotic crayfish species has been allowed. A drastic decline of the immigration of young eels have been noted in Swedish coastal rivers. This has lead to decreased Swedish catches in the Baltic, while the catches on the west coast have remained unchanged. Fishery management must be carried out in such a way that biodiversity will not deteriorate. In chapter 9 biodiversity in stream populations is studied with the use of electrofishing data. Negative effects on biodiversity were mainly found in acidified waters and waters with extensive hydroelectric power development. It was concluded that biodiversity in general had remained unchanged or improved slightly during the last two decades, much thanks to liming and fishery management. A programme for monitoring of the biodiversity in the four great lakes has recently started, and preliminary results suggests that some non-commercial species need specific attention, e.g. river lamprey and Aspius aspius.

Resursövervakningen av sötvatten, RASKA, bygger dels på Fiskeriverkets egna undersökningar, men till stora delar också på sammanställning av uppgifter framtagna av andra myndigheter, organisationer och ideella föreningar. RASKA är således beroende av beredvilligheten hos andra att dela med sig av sin information. Vår förhoppning är att sammanställningen och syntesen skall ge mer information än de olika delarna var för sig och att vi därigenom kan ge en samlad överblick över ett större antal vatten tillbaka till de enskilda uppgiftslämnarna. Avsikten är att detta arbete skall ske gemensamt av Fiskeriverket och Laxforskningsinstitutet. Inom Fiskeriverket sker samordningen och dataläggningen vid Sötvattenslaboratoriet, Örebro, medan Fiskeriverkets utredningskontor skall svara för dataleverans, materialanalys och syntesansvar vad gäller havsöring och lax. The present report gives the status of fishpopulations in inland waters and coastal rivers in Sweden. The stock data were compiled from several different authorities, e.g. different counties, communities, sport fishingsassociations, the Salmon Research Institute and the National Board of Fisheries. The stock data consist of electrofishing results, fish ladder counts, fishing statistics and stockings from rivers. From the four greatest lakes data consist of fishery statistics, preyspecies abundances (hydroacoustics) and stockings. Environmental data added weretemperature, water quality and water flow. Anadromous salmon and trout on the Swedish west coast have increased considerably due to liming, elimination of migratory obstacles and a reduced sea fishery (e.g.Figures 4 & 5 showing number of parr/100m2 in Rivers Ätran and Fylleån, respectively). During the period 1990-95 drought and following low discharge has been a problem reducing parr abundances. Intensified monitoring is suggested in the future. Due to overexploitation by the sea and coastal fishery, natural anadromous salmon and trout stocks in the Baltic are below acceptable levels, with increasing risk of genetic detonation and considerable economic losses. For salmon the effects of the M74 syndrome, i.e. excessive fry mortality, has further reduced the stocks. Figure 19 shows the average mortalities of fry from hatcheries at salmonrivers running to the Gulf of Bothnia. The total catch must decrease, especially the catch with drift nets and lines in the open sea, which is carried out on mixed stocks. Lake resident salmon occur naturally only in Lake Vänern, where the two stocks have suffered heavily from the building of dams for hydroelectric purposes. The natural stocks have been declared to be of national interest. The fishing is based on stocked fish, all without the adipose fin, while the few natural produced fish, i.e. with adipose fin left, are protected. Increased legal size together with increased closed areas are measures that have improved the conditions for the stocks in the last years. Trout populations in inland waters have generally increased on the west and east coast, while stocks in interior Sweden and in the mountain range have remained unchanged during the last two decades. Liming, habitat restoration and increased closed areas are considered the most important measures for the stocks in the future. Approximately 230 commercial fishermen utilize the four great lakes (Vänern, Vättern, Mälaren, Hjälmaren). Detailed fishery statistics are collected on a monthly basis, including effort. In Lake Vänern salmon (’lax’) and trout (Coring’) together with whitefish (’sik’) and cisco (’siklöja’) dominate the catch (Figure 50). Roe from cisco contribute swith approximately 50% of the catch value. In Lake Vättern the catch is dominated by salmon, Arctic char (’röding’) and whitefish (Figure 54 shows the catches since 1914). Stocking of salmon, a new species in the lake, gives a high yield; 600-1,000 kg salmon /1,000 smolts released. Monitoring is carried out to study if the salmon stockings will have negative effects on the resident Arctic char, as the two species compete for the same prey species. In Lake Mälaren (Figures 58, 60) and Hjälmaren (Figures 64, 65) eel (’ål’) and zander (pikeperch, ’gös’) are important species. The eel fishery is completely dependent on stockings. In the former lake cisco was important until late 80’s, but then the population drastically declined, due to recruitment failure. The status of the crayfish (Astacusastacus) is given in chapter Crayfish (Kräftor). The crayfish plague was spread from Finland to Sweden in 1907 and many populations of the native crayfish have been eradicated.The plague later was further spread due to introduction of the american crayfish (Pacifastacus leniusculus). Today Astacusastacus is considered an endangered species in southern Sweden, and restriction on stockings of the american crayfish has been imposed. A drastic decline of the immigration of young eels have been noted in Swedish coastal rivers (Figure 71). This has lead to decreased Swedish catches in the Baltic, while the catches on the west coast have remained unchanged. Fishery management must be carried out in such a way that biodiversity will not detoriate. In the last chapter (Biologisk mångfald) biodiversity in stream populations is studied with the use of electrofishing data. Negative effects on biodiversity were mainly found in acidified waters and waters with extensive hydroelectric power development. It was concluded that biodiversity in general had remained unchanged during the last two decades, much thanks to liming and fishery management. A programme for monitoring of the biodiversity in the four great lakes has recently started, and preliminary results suggests that some non-commercial species need specific attention, e.g. River lamprey. RASKA är en sammanställning av statistik framtagen av Fiskeriverket och Laxforskningsinstitutet i samarbete med andra myndigheter, organisationer och ideella föreningar

The report summarises the monitoring activities within the National Swedish Contaminant Programmefor freshwater biota. Each monitored contaminant has been examined in pike, perch or Arctic char from32 lakes from the north to the south in Sweden.No general trend could be seen for mercury, and all samples were above the EU threshold. Lead wasgenerally decreasing and concentrations were below the target level in all lakes. Cadmiumconcentrations showed no consistent trends over the monitored period, and cadmium concentrationswere below the target level in all lakes. Chromium concentrations are below the limit of quantification(LOQ) in most lakes after 2010. For nickel, arsenic, copper, zink, silver, and aluminium there were noclear temporal trends, with both upward and downward trends. Tin concentrations were below the LOQfor most sampling sites and throughout all years of sampling.In general, downward trends were seen for; PCBs, HCHs, DDT, DDE and PCDD/Fs in all species (with afew exceptions). The chlorinated compounds generally showed a somewhat higher concentration in thesouthern parts of Sweden. Most chlorinated compounds were below the suggested target levels.No general trend was seen during the monitoring period for PBDEs. However during the most recent 10year period, downward trends were seen in pike from Bolmen. The concentration of HBCDD was underLOQ in a majority of the samples.Several of the perfluorinated carboxylic compounds showed a non-linear increase in concentration inarctic char, while no trend was seen for PFOS. In perch, PFOS has decreased since 1980 while upwardtrends were seen for several carboxylic acids from 1980. Higher concentrations of perfluorinatedcompounds can in general be seen in the southern part of Sweden. In all lakes, PFOS is below thetarget level for all species.

This thesis evaluates the environmental performance of six different fish farming systems. The thesis is part of the network group “Hållbar fiskförsörjning I Stockholms län” (HFFS) which tries to increase the domestic and regional production of fish in Stockholm and move to a more sustainable supply in the Stockholm county. Two of the chosen systems; pangasius from Vietnam and salmon from Norway are delivering a substantial part of the fish consumed in Stockholm today, although they are very different when it comes to system characteristics. One system, arctic char with conventional feed, is produced in a fairly small scale in the north of Sweden, while the three remaining systems are viewed upon as possible options to supply Stockholm with fish in the future. Two of these three systems are fed with Baltic Blend which is a new fish feed developed at SLU, Uppsala. The idea of the new feed is to lower the environmental burden by substituting parts of the fish meal with other protein sources such as mussels and microbes. Two of the Swedish systems are recirculating and land-based (RAS), which is a fairly new but growing fish production system worldwide. The life cycle assessment in this study shows that domestic production of fish not necessarily is environmentally preferable but has the potential to be so if some processes can be performed more efficiently. The greatest improvement potential is found in the production of the new feed ingredients, the grow-out phase and the slaughter and guttering of the fish.