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1281 Uppsatser om Sediment-living organisms - Sida 1 av 86
Ivermektins påverkan på organismer i vatten och sediment
Endektociden ivermektin används i stor omfattning inom veterinärmedicinen. Läkemedlet metaboliseras i låg grad och kommer ut som verksamt ämne i faeces och utövar sina effekter på andra än målorganismerna, bl.a. faeceslevande arter. Eftersom vissa vattenlevande organismer uppvisar en särskild känslighet kommer denna litteraturstudie att fokusera på ivermektins toxicitet på organismer i akvatisk miljö och huruvida dessa kan vara i fara i svenska vatten.
Daphnia magna är den art som visat sig känsligast och effekter har setts på nivåer så låga som 0,001 ng/l. Ivermektin verkar vara särskilt toxiskt för cladoceraner, den ordning som D.
Båtbottenfärger innehållande TBTO : huvudsaklig källa till TBT i miljön
Antifouling paint containing the biocide bisTributyltinoxide (TBTO) has been used since1960 to reduce the occurrence of fouling on hulls on boats/ships. January 1st, 2003 theantifouling paints containing TBTO were prohibited. This ban covered all use of paintcontaining the substance TBTO. The ban was introduced because of alarming observationssuch as development of imposex in aquatic non-target organisms. Imposex is the impositionof male sexual characteristics on mainly female marine snails and occurs due to exposure toTributyltin (TBT).
Biologisk bekämpning av Fusarium graminearum
Fusarium graminearum causes reduction in both yield and quality in cereal grain worldwide. One of the diseases it can cause is Fusarium Head Blight (FHB). Both sexually and asexually produced spores can infect living plants. Asexual conidia are produced in the mycelium while sexual ascospores form in asci in perithecia on debris. In biological control, living organsims are used to control pests and diseases.
Sedimentation av lera och fosfor i en anlagd våtmark
The amount of various phosphorus (P) fractions in the sediment and the relationship between the amount of P and sediment particle size were investigated in a constructed wetland southwest of Linköping. Furthermore, the possible correlation between clay content in the sediment and distance from the inlet was investigated. Sediment samples were collected along three transects from the inlet to the outlet, with six samples in each transect. In order to measure the soluble P, an NH4Cl extraction was done. This was also analysed for total soluble P after oxidation with peroxodisulphate.
Skogen i barnlitteraturen : Kan den fungera som en källa till naturvetenskaplig kunskap?
The amount of various phosphorus (P) fractions in the sediment and the relationship between the amount of P and sediment particle size were investigated in a constructed wetland southwest of Linköping. Furthermore, the possible correlation between clay content in the sediment and distance from the inlet was investigated. Sediment samples were collected along three transects from the inlet to the outlet, with six samples in each transect. In order to measure the soluble P, an NH4Cl extraction was done. This was also analysed for total soluble P after oxidation with peroxodisulphate.
Genomgång av kemikalieförteckning som exempel på uppströmsarbete : en identifiering av utfasningsämnen i spillvattnet
Benthic invertebrates play important roles as feeding resources for many organisms in different food webs. Shifts in predation of these organisms can generate cascading effects and potentially lead to the disappearance of one or more species from a site. Cascading effects can bring impacts to organisms who aren?t even directly involved, why studies in this field are important for understanding sudden changes in ecosystems. I examined the predation from fish and waterfowl on benthic invertebrates in the shallow and eutrophic Lake Tåkern in the plains of Östergötland County, southern Sweden.
Variationer i omgivningsmiljö som faktor till variationer i fluvial transport av upplöst sediment : En studie av Librobäckens nedre delar och dess omland
För att förhindra övergödning används skyddszoner i stora delar av Sverige där jordbruk utförs. Det finns även andra faktorer som kan bidra till, eller förhindra, förluster av sediment via fluviala element i landskapet. Variationer i ett vattendrags omland påverkar hur den fluviala transporten av sediment ser ut. Syftet med den här studien är att kartlägga vilka faktorer som kan påverka hur transporten av upplöst sediment ser ut i Librobäckens nedre delar. Hur variationer i omgivningsmiljön skulle kunna skapa variationer i transporten av upplöst sediment.
Predation på evertebrater under tidig vår i sjön Tåkern
Benthic invertebrates play important roles as feeding resources for many organisms in different food webs. Shifts in predation of these organisms can generate cascading effects and potentially lead to the disappearance of one or more species from a site. Cascading effects can bring impacts to organisms who aren?t even directly involved, why studies in this field are important for understanding sudden changes in ecosystems. I examined the predation from fish and waterfowl on benthic invertebrates in the shallow and eutrophic Lake Tåkern in the plains of Östergötland County, southern Sweden.
Deadwood in piles or distributed : does it make any difference to saproxylic beetles?
Piles of deadwood are often retained in forests after management to support the biodiversity ofsaproxylic organisms which depend on deadwood to survive. Any knowledge about the crucial role ofpiles as suitable habitat of saproxylic organisms compared to single distributed deadwood objects thatare around the piles would help conservation actors to motivate more forest owners to supportsaproxylic organisms during their management. Therefore to give facts to this the saproxylic fauna ofdifferent pile positions (up and low) was studied and compared to distributed deadwood samplesaround each pile. Our study was focused on saproxylic beetles. Some other parameters such asdiameter, deadwood volume, pile volume and decay stage were assessed to define any effect.
Omkonstruktion av kolvlod : På uppdrag av institutionen för geologiska vetenskaper Stockholms universitet
On ocean beds around the world sinking particles of residual biomass from animals and vegetation have, over time, accumulated into thick layers of sediment. For researchers these layers of sediment contain valuable information about the earth?s past climate, information that can be used to predict future climate change and to estimate natural vs. human causes of today?s global warming.The Institute of Geosciences at Stockholm University studies sediment cores that have been acquired with an apparatus called piston corer.
En studie av sedimenttransport, död ved och kantzoner längs två vattendrag i Kilsbergen - från skog till slätt :
Headwater streams are affected by anthropogenic impacts at multiple scales.
One aspect of human impact is sediment transport associated to the
abundance of stream structures as large woody debris and the composition
of the riparian zone from forest to agricultural landscapes.
Riparian buffer zones and stream structures like dead wood are considered
as generally important structures for protection against an increasing
amount of sediment particles in the water. Hence, in this study these
structures were quantified in thirty different stream segments on land and in
the water.
To measure the transport of sediment Whitlock-Vibert boxes were used in
three different types of landscapes; forest, transition and fields. The boxes
were left in the stream segments for three months, the taken up and dried
and weighed. The results showed that the transition-land in Frösvidalsån
had the highest sediment transport. The second highest transport of
sediment was in Blackstaån at the fields.
Flodpärlmusslans status i Laxtjärnbäcken : Effekter på flodpärlmusslan av sedimentbelastning och förekomst av bäckröding
The aim of this present study was to determine and evaluate whether the presence of brooktrout (Salvelinus fontinalis) and sediment load may be a threat against the reproduction anddistribution of freshwater pearl mussel (Margaritifera margaritifera) in a creek located innorthern Sweden. Freshwater pearl mussel is an endangered species and is dependent ofbrown trout (Salmo trutta) to reproduce. Therefore there are concerns of indirect effects onthe population of pearl mussel by competition between brown trout and brook trout. Ditchesfrom a nearby gravel road have been fixed to lower the sediment load into the creek. I tried toevaluate this action plan.
Metodutveckling för analys av PBDE och HBCD i sediment
Brominated flame retardants (BFRs) has for many years been used in products to reduce their
flammability, mainly in electronic products, textiles and construction materials.
In 2003, Sweden imported 300 tons of brominated flame retardants.
Leakage of these compounds has polluted natural environments. Fishes has shown increased
contents of these substances, especially fat fish, since brominated flame retardants tends to
accumulate in fatty tissues.
They are also regarded as persistent and that gives them the ability to travel long distances.
What also is really scary is that increased levels of brominated flame retardants have been
detected in human breast milk.
The knowledge of the brominated flame retardants is limited and not so much research has been
done in this field. There are many reasons though, to keep the research going. Partly their
structural resemblance to well-known toxics as PCB, but also their ability to accumulate in
biological systems and enrich in food chains.
In which way they affect humans we really don?t know yet.
Fröåtjärns föroreningshistoria : Utredning av hur metallbelastningen varierat över tid med hjälp av sediment som ett naturligt historiearkiv
The metal mining history goes thousands of years back. The downside of the mining industry is the large amount of tailings created during the mining operations. Drainage and leaching of heavy metals from these tailings may cause major environmental problems including acid mine drainage and leaching of heavy metals. This study examines a pond located near an old mining site, where part of the old mining facility has been recently (1990) restored. The objective was to assess eventual metal contamination from historical mining and the recently performed restoration using a sediment core as a natural archive of historical metal inputs to the pond.
Sedimentprovtagning av dagvattendammar som ett alternativ till flödesproportionell vattenprovtagning
Stormwater run-off from surfaces such as roads or rooftops is often polluted with heavy metals and nutrients. Many of these substances can cause great damage in biota if they end up in the recipient. In Sweden constructed wetlands and ponds for treatment of stormwater are frequently used, since research has shown that these treatment ponds are reducing stormwater pollution considerably to a low cost. The knowledge of these pollutant removal mechanisms and how follow-up and assessment of the ponds should be performed is still limited.To determine the pollutant removal efficiency of the stormwater ponds it is recommended that flow-weighted water samples are collected from both the inflow and the outflow of the pond. This method demands considerable resources of time and money for installations and analysis.