| 1. |
|
|
| 2. |
|
|
| 3. |
- Baden, Susanne P., 1952, et al.
(författare)
-
Vanishing seagrass (Zostera marina, L.) in Swedish coastal waters
- 2003
-
Ingår i: Ambio. - 0044-7447. ; 32:5, s. 374-377
-
Tidskriftsartikel (refereegranskat)abstract
- Along the Swedish Skagerrak coast eelgrass (Zostera marina) is a dominant phanerogam on shallow soft bottoms. Eelgrass meadows are important biotopes for many crustacean and fish species being either migratory or stationary. During the 1980s, inventories of the shallow coastal areas with eelgrass have been carried out along the Swedish west coast as a basis for coastal zone management. In the present study we revisited 2000 ha of eelgrass meadows in 5 coastal regions along 200 km of the Skagerrak coast. The inventory was made with the same methods (aquascope) as during the 1980s, but increasing the mapping accuracy by using a Global Positioning System (GPS). The results from this study show that the areal extension of Zostera marina has decreased 58% in 10-15 years with great regional variations. The decline was mainly restricted to the shallow parts of the meadow. The causes and ecological consequences are discussed.
|
|
| 4. |
- Bekkby, Trine, et al.
(författare)
-
Marine habitaters utbredelse - terrängmodellering i Gullmarsfjorden
- 2006
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Denne rapporten presenterer framgangsmåten, resultatene og diskusjonen rundt arbeidet med modellering av de relevante marine habitatene. Rapporten, figurene og dataene som ligger til grunn for figurene vil også være tilgjengelig på cd som leveres Länsstyrelsen Västra Götaland Län ved prosjektets slutt.
|
|
| 5. |
- Bergkvist, Johanna, et al.
(författare)
-
Test och utvärdering av ny övervakning av främmande arter i hamnar och utsatta områden
- 2017
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Övervakning av hamnar och farleder är ett viktigt instrument för att tidigt upptäcka nya främmande arter och hindra dess spridning. På uppdrag av Havs- och vattenmyndigheten har Marine Monitoring AB utfört Test och utvärdering av ny övervakning av främmande arter i hamnar och utsatta områden. Undersökningen baseras på Metoder för övervakning av främmande arter. Protokoll för provtagning i hamnar och farleder samt Havs- och vattenmyndighetens manual Undersökningstyp: Främmande arter. Främmande arter som sprids med barlastvatten anses vara ett av de största ekologiska och ekonomiska hoten mot planeten. Behandling av barlastvatten och övervakning i hamnar syftar till att minska spridningen samt att tidigt upptäcka nya arter. Till testområde utsågs Preem AB:s hamn i Brofjorden norr om Lysekil. Inom hamnen togs prover i två områden, ett inre och ett yttre. Vidare togs prover vid Dynabrott och Brandskärs flak vid inloppet till Brofjorden. Undersökningen täcker in många olika habitat och prover tas på bottenfauna, växt- och djurplankton, påväxt och mobil epifauna. Totalt dokumenterades cirka 365 arter, varav fem betraktas som främmande i svenska vatten: amerikansk kammanet (Mnemiopsis leidyi), dinoflagellaten Karenia mikimotoi, japanplym (Dasysiphonia japonica), japanskt jätteostron (Crassostrea gigas) och slät havstulpan (Amphibalanus improvisus). Generellt har metoderna inom övervakningen fungerat bra, men vissa oklarheter förekommer i metoden och undersökningstypen och behöver förtydligas. Båt med vinsch eller lindragare rekommenderas för flera av momenten då de är för tunga för att utföras säkert manuellt. Provtagningen är omfattande och tidskrävande varför samordning med olika nationella program kan ge vinster, dels ekonomiskt men även i form av att utnyttja den taxonomiska kompetensen inom dessa program.
|
|
| 6. |
- Bergström, Lena, et al.
(författare)
-
Effects of offshore wind farms on marine wildlife-a generalized impact assessment
- 2014
-
Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 9:3
-
Tidskriftsartikel (refereegranskat)abstract
- Marine management plans over the world express high expectations to the development of offshore wind energy. This would obviously contribute to renewable energy production, but potential conflicts with other usages of the marine landscape, as well as conservation interests, are evident. The present study synthesizes the current state of understanding on the effects of offshore wind farms on marine wildlife, in order to identify general versus local conclusions in published studies. The results were translated into a generalized impact assessment for coastal waters in Sweden, which covers a range of salinity conditions from marine to nearly fresh waters. Hence, the conclusions are potentially applicable to marine planning situations in various aquatic ecosystems. The assessment considered impact with respect to temporal and spatial extent of the pressure, effect within each ecosystem component, and level of certainty. Research on the environmental effects of offshore wind farms has gone through a rapid maturation and learning process, with the bulk of knowledge being developed within the past ten years. The studies showed a high level of consensus with respect to the construction phase, indicating that potential impacts on marine life should be carefully considered in marine spatial planning. Potential impacts during the operational phase were more locally variable, and could be either negative or positive depending on biological conditions as well as prevailing management goals. There was paucity in studies on cumulative impacts and long-term effects on the food web, as well as on combined effects with other human activities, such as the fisheries. These aspects remain key open issues for a sustainable marine spatial planning.
|
|
| 7. |
- Bergström, Lena, et al.
(författare)
-
The effects of wind power on marine life : A Synthesis
- 2012
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- As in many other countries, an expansion of wind power is expected in Sweden during the coming decades. The expansion is driven by rising prices on electricity and the need for an increased production of renewable energy. Since wind conditions at sea are good and relatively constant, several offshore wind farms are planned in Swedish waters. Offshore wind power with a total effect of about 2500 MW has been granted permission and an additional 5500 MW are being planned for. Examples of granted projects are Storgrundet with an effect of 265 MW, Stora Middelgrund with an effect of 860 MW and Kårehamn with an effect of 48 MW. The largest offshore wind farm in Sweden today is Lillgrund in Öresund, with its 48 turbines with an installed effect of 110 MW.Prior to this expected expansion, it is important to investigate the environmental impact of offshore wind power, and how possible negative effects can be minimized. This synopsis about the impact of wind power on the marine life in Swedish waters is based on more than 600 studies, most of which are scientific articles, but also reports by companies and authorities.Habitats and species in Swedish marine areasSwedish marine areas are characterized by a unique salinity gradient that varies from marine conditions in Skagerrak to almost limnic environments in the Gulf of Bothnia. There are also vast differences between areas in terms of environmental factors such as insolation, temperature and wave exposure. This entails variation in species composition, dominance by different populations and structural differences in plant and animal communities. Therefore, this synopsis provides environment descriptions of three widely separated marine areas: the Swedish West Coast (Kattegat and Skagerrak), the Baltic Proper and the Gulf of Bothnia (Bothnian Sea and Bothnian Bay). The main focus is on occurrence of species and communities within the depth interval that is of interest for establishing offshore wind power in Sweden.Offshore wind powerThere are mainly two types of foundation structures used in Sweden today: gravity-based foundations and monopile foundations. These are also the most commercially viable. Offshore wind farm projects affect the environment in different ways during installation, operation and decommissioning. The installation phase is assessed as having the largest impact on the environment, since high noise levels and sediment dispersal can affect marine organisms. A wind farm during operation can cause barrier effects as well as changes in the natural environment. The decommissioning phase can again enhance noise levels and lead to sediment dispersal in the wind park and its adjacent area. Effects on marine organisms and communities Since marine environmental conditions vary between different locations as well as over time, it is difficult to make universal assessments of the effects of offshore wind power. This increases the importance of well-designed pilot studies and monitoring programs of the local environment. Also, location-specific surveys minimize the risk that costly measures to reduce negative impact are used when they are not needed. In general, installation and decommissioning of offshore wind farms should be planned so that sensitive reproductive periods for marine species are avoided. Particular consideration might also be needed for constructions in important growth and spawning areas for fish and marine mammals, or specific environments, such as offshore banks with high natural values. Below is a list of the effects that, according to existing knowledge and accessible literature, might affect marine organisms and communities. Each effect has been assessed after how long, and to what scale, it affects the marine life in the wind farm area.Acoustic disturbances during the installationAs monopile foundations are being driven into the sea floor, a lot of noise is generated that spreads in the water. Cod and herring can potentially perceive noise from pile driving at a distance of 80 kilometres, experiencing physical damage and death at just a few meters from the place of installation. For all types of work involving noise, flight reactions in fish are expected within a distance of about one kilometre from the source. The greatest risk of significant harm to fish populations exists if the installation overlaps with important recruitment areas for threatened or weak populations. Among the marine mammals, porpoises have proved to get both impaired hearing and behavioural disturbances from noise associated with pile driving. There are no studies indicating any long-term negative effects on any of the seal species occurring in Swedish waters. It is not possible to draw any general conclusions of the effects on invertebrates from pile driving noise, since the group is too large and diverse. The few studies that exist, however, show that oysters are relatively sensitive, whilst mussels are not affected at all. The effects of high noise levels can be reduced by, for example, successively increasing the power and thus the noise during piling, so that larger animals such as fish, seal and porpoises are intimidated at an early stage and leave the construction area well before high noise levels are reached.Sediment dispersalDredging work during the construction of gravitational foundations, and laying of cables between the wind turbines and land, can cause sediment from the bottom to whirl up and disperse in the water mass. The amount of sediment dispersed depends on the type of sediment, water currents and which dredging method is being used. Increased concentrations of sediment in the water affect mainly fish fry and larval stages negatively. Invertebrates are often adapted to re-suspension of sediment, since it occurs naturally in their environment. The sediment dispersal at the construction of a wind farm is often confined to a short period. The effects are also relatively small due to the fact that the bottom sediment is usually coarse-grained. The overall assessment is therefore that sediment dispersal is a limited problem for most animal and plant communities, but specific consideration should be taken and fish recruitment periods should be avoided.Introduction of a new habitatThe foundations of wind turbines can function as artificial reefs and attract many fish species, particularly around gravitational foundations which have a structurally complex erosion protection. At first there is often a redistribution of fish from nearby areas to the wind park foundations, but over time an actual increased fish production within the park is possible, as long as the park is large enough and the fishing pressure is low. The structure of the erosion protection can bring local positive effects for crustaceans such as lobster and crab, by functioning as shelter as well as increasing their foraging area. One example of a species that seems to increase locally around foundation structures on the Swedish West Coast and the Baltic Proper is the blue mussel. Which species that will dominate depends on the salinity in the area. There are no studies showing that foundation structures will facilitate the distribution of new species to Swedish marine areas. One reason for this might be that the total amount of hard bottom surface formed by the foundations and their structures is relatively small compared to natural hard bottoms.Turbine noise and boat trafficMaintenance work on the wind turbines causes a certain increase in boat traffic in the area of an operating wind farm. Also, different parts of the turbines generate noise during operation that spreads through the water. The reactions of fish on noise from turbines and boat engines vary, but study results indicate that the effect on most fish species from noise produced in a wind farm is low. There are, however, no studies on long-term effects of stress due to an increased noise level or effects of noise disturbance on fish spawning behaviour. Porpoises especially, but to some extent also seals, are sensitive to noise disturbance. Today there are no studies showing negative effects from the operational sounds from a wind farm on populations of marine mammals. The noise of both strong winds and engines from ships often exceeds the underwater noise generated by operating wind farms.Electromagnetic fieldsThe electric cables leading from a wind turbine generates a magnetic field that decreases with distance from the cable. The expected effect on most fish species is low, but since the effect is ongoing throughout the entire operational stage, the risk should be considered in areas that are important to migrating fish species. No studies have been found that show how electromagnetic fields affect marine mammals. The few studies that have been found on invertebrates indicate that the electromagnetic fields around common transmission cables have no effect on either reproduction or survival.Exclusion of birdsMost birds do not avoid wind farm areas. An exception is several common diving ducks that avoid flying or swimming within wind farms and keep a safe distance of at least 500 meters to a turbine tower. The most common food for these species in the Baltic Sea is blue mussels. Areas within the Swedish economic zone where a large-scale expansion of wind power would have the greatest effect on the ducks, and thereby indirectly affect the benthic community, are the offshore banks in the central Baltic Proper, mainly Hoburg Bank and Northern Midsjö Bank, where two thirds of the oldsquaw populations in Europe overwinters. The level of impact will depend on the total area of the park, and the distance between the turbine towers. Large-scale studies are needed in order to assess if the effect might lead to substantial changes for the benthic community.Gaps of knowledgeThe basis of this synopsis is research results from studies concerning single wind turbines or small wind farms, which in many
|
|
| 8. |
- Bergström, Lena, et al.
(författare)
-
Vindkraftens effekter på marint liv : En syntesrapport
- 2012
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Precis som i manga andra lander forvantas en utbyggnad av vindkraft i Sverige under de narmaste decennierna. Expansionen drivs bland annat av stigande elpriser och behovet av okad produktion av fornybar el. I Sverige har havsbaserad vindkraft med en total effekt pa ungefar 2500 MW fatt tillstand och ytterligare 5500 MW ar under utveckling. Exempel pa vindkraftsprojekt med fardiga tillstand ar Storgrundet med en effekt pa 265 MW, Stora Middelgrund med en effekt pa 860 MW och Karehamn med en effekt pa 48 MW. I dag utgor Lillgrund i Oresund med sina 48 vindkraftverk och 110 MW i installerad effekt, Sveriges storstahavsbaserade vindkraftpark. Infor denna forvantade expansion ar det viktigt att undersoka vindkraftens miljoeffekter, och hur eventuella negativa effekter kan minimeras. Over 600 studier, huvudsakligen vetenskapliga artiklar, men aven rapporter fran foretag och myndigheter, ligger till grund for slutsatserna och rekommendationerna i denna syntesrapport om paverkan av vindkraft pa det marina livet i svenska havsomraden. [...]
|
|
| 9. |
- Conley, Daniel, et al.
(författare)
-
Hypoxia-Related Processes in the Baltic Sea
- 2009
-
Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 43:10, s. 3412-3420
-
Tidskriftsartikel (refereegranskat)abstract
- Hypoxia, a growing worldwide problem, has been intermittently present in the modern Baltic Sea since its formation ca. 8000 cal. yr BP. However, both the spatial extent and intensity of hypoxia have increased with anthropogenic eutrophication due to nutrient inputs. Physical processes, which control stratification and the renewal of oxygen in bottom waters, are important constraints on the formation and maintenance of hypoxia. Climate controlled inflows of saline water from the North Sea through the Danish Straits is a critical controlling factor governing the spatial extent and duration of hypoxia. Hypoxia regulates the biogeochemical cycles of both phosphorus (P) and nitrogen (N) in the water column and sediments. Significant amounts of P are currently released from sediments, an order of magnitude larger than anthropogenic inputs. The Baltic Sea is unique for coastal marine ecosystems experiencing N losses in hypoxic waters below the halocline. Although benthic communities in the Baltic Sea are naturally constrained by salinity gradients, hypoxia has resulted in habitat loss over vast areas and the elimination of benthic fauna, and has severely disrupted benthic food webs. Nutrient load reductions are needed to reduce the extent, severity, and effects of hypoxia.
|
|
| 10. |
|
|
