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| 2. |
- Andersson, Magnus, et al.
(författare)
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Fiskbestånd och miljö i hav och sötvatten : Resurs- och miljööversikt 2012
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Detta är den nionde utgåvan av den samlade översikten över fisk- och kräftdjursbeståndens status i våra vatten. Kunskap om fiskbestånden och miljön är en förutsättning för att utnyttjandet av fiskresurserna skall bli bärkraftigt. För svenska vattenområden beskrivs miljöutvecklingen i ett ekosystemsperspektiv, dels för att tydliggöra fiskens ekologiska roll och beskriva yttre miljöfaktorer som påverkar fiskbestånden, dels för att belysa fiskets effekter på miljön.Fiskbestånd och miljö i hav och sötvatten är utarbetad av Sveriges lantbruksuniversitet (SLU), Institutionen för akvatiska resurser (SLU Aqua), på uppdrag av Havs- och vattenmyndigheten. Rapporten sammanfattar utveckling och beståndsstatus för de kommersiellt viktigaste fisk- och kräftdjursarterna i våra vatten. Bedömningar och förvaltningsråd är baserade på Internationella Havsforskningsrådets (ICES) rådgivning, SLU Aquas nationella och regionala provfiskedata, samt yrkesfiskets rapportering.
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| 5. |
- Almqvist, Gustaf, et al.
(författare)
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Has the invasive round goby caused new links in Baltic food webs?
- 2010
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Ingår i: Environmental Biology of Fishes. - : Springer Science and Business Media LLC. - 0378-1909 .- 1573-5133. ; 89:1, s. 79-93
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Tidskriftsartikel (refereegranskat)abstract
- The Ponto-Caspian round goby (Neogobius melanostomus, Pallas 1814) most probably was established in the Gulf of GdaA""sk, Baltic Sea, in the late 1980's and has since become one of the dominant species in the region. In this study we assess the role of round gobies as prey for two important fish species in the Gulf of GdaA""sk, cod (Gadus morhua) and perch (Perca fluviatilis). We compared their present diet with stomach analyses from the area prior the round goby establishment, as well as with diet analysis from Baltic regions where round gobies are absent. There were large differences in the diet between cods from the Gulf of GdaA""sk 2003-2006 compared to cods in earlier studies (1977-1981) from the Southern Baltic Sea. There were also large differences in cod and perch diets from areas with and without round goby. Presently, round goby constitutes the most important prey for medium sized cods in Gulf of GdaA""sk, and perch from the same area almost exclusively feed on gobiids. Stomach analysis, trophic level estimates, and stable isotope analyses all indicated that cod and perch in Gulf of GdaA""sk after the round goby establishment belonged to a similar trophic level. Beside round goby, no mussel feeding fish contributed much to the diet of cod or at all to the diet of perch. Thus, it is likely that round gobies constitute a new energetic pathway from mussels to top predators. However, due to the short time elapsed after round goby establishment, we can only speculate on the species future impacts on Baltic food webs.
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| 6. |
- Almqvist, Gustaf, 1972-
(författare)
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Round goby Neogobius melanostomus in the Baltic Sea – Invasion Biology in practice
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Human mediated transfer of non-indigenous species is considered to be a major threat to global biodiversity. The Ponto-Caspian round goby (Neogobius melanostomus), which has established populations in various regions in Eurasia and North-America, was first observed in Gulf of Gdańsk, Baltic Sea, in 1990. In this thesis the round goby is used as case study for assessing the invasion process of an alien species in to the Baltic Sea. Factors governing life history characteristics, traits that have enhanced the invasion, and ecological consequences for the Baltic Sea are assessed. Two diverging life history strategies of the round goby related to habitat were found: one to-wards early maturation and short population turnover time in sheltered areas, the other towards high growth rate and late maturation in exposed areas. Females produced two batches in average during the spawning season. Lengths of spawning season and annual fecundity of round gobies in Gulf of Gdańsk were in the same range as in the donor region. The species was found to compete with juvenile flounder for space and food resources, and probably also other native species are affected in coastal areas. Round goby comprised a main food source for cod and perch, forming a new energetic pathway between mussels and predatory fish. It is predicted that the species must produce more than one batch per season to sustain a viable population. Low temperature in the northern Baltic Sea is expected to hamper the devel-opment of new round goby populations, however, the global climate change might change this situation. In the southern Baltic Sea a shortage of optimal reproduction habitats is suggested to moderate the rate of spread. Although round goby in the Gulf of Gdańsk seems to have passed abundance maximum it is likely that the species will continue to be an important ecosystem component, at least in southern Baltic Sea, in the future.
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| 7. |
- Appelberg, Magnus
(författare)
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7. Fish Communities
- 2012. - 1
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Ingår i: Ecology and Animal Health. - Uppsala : Baltic University Press. - 9789186189129 ; , s. 56-62
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Bokkapitel (populärvet., debatt m.m.)
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| 8. |
- Appelberg, Magnus, et al.
(författare)
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Strategi för ett samordnat nationellt/regionalt övervakningsprogram för kustfisk i Bottniska Viken
- 2003
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Övervakning av kustfiskbestånd har tidigarefrämst varit inriktad mot att bedöma förändringari för fisket viktiga arter och årsklasseroch i mindre utsträckning mot attbedöma förändringar relaterade till biologiskmångfald. Under 2002 startade länsstyrelsernai Norrbottens, Västerbottens, Västernorrlandsoch Gävleborgs län, Fiskeriverket,Umeå Marina Forskningscentrum och Naturvårdsverketett projekt med syfte att utarbetaen strategi för ett samordnat nationellt/regionalt övervakningsprogram för kustfiski Bottniska viken. Projektet finansieras avNaturvårdsverket och Fiskeriverket. Ett samordnatövervakningsprogram är framför alltnödvändigt för att klara uppföljningen av detnationella miljömålet ”Hav i balans samtlevande kust och skärgård” och motsvaranderegionalt formulerade mål. Ambitionen är attsamordning även kan göras med uppföljningenenligt EU:s ramdirektiv för vatten. I föreligganderapport redovisas resultaten frånprojektets första år. Resultaten omfattar jämförelsermellan två provfiskestrategier ochett preliminärt förslag till strategi för ett samordnatövervakningsprogram för kustfisk.
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| 9. |
- Bergek, Sara, et al.
(författare)
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From individuals to populations : Impacts of environmental pollution on natural eelpout populations
- 2012
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Ingår i: Ecotoxicology and Environmental Safety. - : Elsevier BV. - 0147-6513 .- 1090-2414. ; 79, s. 1-12
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Forskningsöversikt (refereegranskat)abstract
- Investigating how individuals are affected by environmental pollution is relatively straightforward, for example through conducting field studies or laboratory toxicity tests. Exploring such effects at a population level is considerably more difficult. Nonetheless, the exploration of population-level effects is important as the outcomes may differ from those seen at the individual level. Eelpout (Zoarces viviparus L) have been used for several years as a bioindicator for hazard substances in both the field and laboratory tests, and individual effects on reproduction have been reported. However, the influence of these effects at the population level remained unexplored. In this study, four Leslie matrix models were parameterized using data from non-polluted eelpout populations (Skagerrak, Baltic Proper, Gulf of Bothnia and Gulf of Finland). The four sites represent an environmental gradient in salinity. Furthermore, life-history data revealed differences between the sites with growth rate, fecundity, age at maturity and longevity being the most significant. The effect of pollution on natural eelpout populations was then simulated by combining the outputs from the Leslie matrices with data from laboratory and field studies exploring reproductive impairment in contaminated environments. Our results show that despite differences in life-history characteristics between sites, survival of early life stages (i.e. larvae and zero-year-old fish) was the most important factor affecting population growth and persistence for all sites. The range of change in survival of larvae necessary to change population dynamics (i.e. growth) and persistence is well within the range documented in recipient and experimental studies of chemicals and industrial waste waters. Overall, larval malformation resulting from environmental pollution can have large effects on natural populations, leading to population losses and possibly even extinction. This study hereby contributes valuable knowledge by extending individual-level effects of environmental contaminants to the population level. (C) 2012 Elsevier Inc. All rights reserved.
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| 10. |
- Bergek, Sara, et al.
(författare)
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Panmixia in Zoarces viviparus: implications for environmental monitoring studies
- 2012
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Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 80, s. 2302-2316
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Tidskriftsartikel (refereegranskat)abstract
- In this study, the genetic population structure of the eelpout Zoarces viviparus was investigated by using microsatellites. Samples were collected at 10 sites in the Baltic Sea, covering a distance of c. 90 km. Ten newly developed microsatellite loci were used to infer the population structure. No global spatial genetic differentiation was found (global F-ST = 0.0001; D-est = -0.0003), indicating strong gene flow at this scale, nor any clear pattern of isolation by distance. The results suggest that gene flow among the studied populations of Z. viviparus is stronger than usually thought, which might be caused by environmental homogeneity. This is important for planning and evaluating monitoring activities in this species and for the interpretation of ecotoxicological studies. Strong migration might lead to wrong conclusions concerning the pollution in a given area. Therefore, reference stations should be placed at a larger distance than presently practiced.
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