Organotin and especially butyltin compounds are used for a variety of applications, e.g. as biocides, stabilizers, catalysts and intermediates in chemical syntheses. Tributyltin (TBT) compounds exhibit the greatest toxicity of all organotins and have even been characterized as one of the most toxic groups of xenobiotics ever produced and deliberately introduced into the environment. TBT is not only used as an active biocidal compound in antifouling paints, which are designed to prevent marine and freshwater biota from settlement on ship hulls, harbour and offshore installations, but also as a biocide in wood preservatives, textiles, dispersion paints and agricultural pesticides. Additionally, it occurs as a by-product of mono- (MBT) and dibutyltin (DBT) compounds, which are used as UV stabilizer in many plastics and for other applications. Triphenyltin (TPT) compounds are also used as the active biocide in antifouling paints outside Europe and furthermore as an agricultural fungicide since the early 1960s to combat a range of fungal diseases in various crops, particularly potato blight, leaf spot and powdery mildew on sugar beet, peanuts and celery, other fungi on hop, brown rust on beans, grey moulds on onions, rice blast and coffee leaf rust. Although the use of TBT and TPT was regulated in many countries world-wide from restrictions for certain applications to a total ban, these compounds are still present in the environment. In the early 1970s the impact of TBT on nontarget organisms became apparent. Among the broad variety of malformations caused by TBT in aquatic animals, molluscs have been found to be an extremely sensitive group of invertebrates and no other pathological condition produced by TBT at relative low concentrations rivals that of the imposex phenomenon in prosobranch gastropods speaking in terms of sensitivity. TBT induces imposex in marine prosobranchs at concentrations as low as 0,5 ng TBT-Sn/L. Since 1993, for the littorinid snail Littorina littorea a second virilisation phenomenon, termed intersex, is known. In female specimens affected by intersex the pallial oviduct is transformed of towards a male morphology with a final supplanting of female organs by the corresponding male formations. Imposex and intersex are morphological alterations caused by a chronic exposure to ultra-trace concentrations of TBT. A biological effect monitoring offers the possibility to determine the degree of contamination with organotin compounds in the aquatic environment and especially in coastal waters without using any expensive analytical methods. Furthermore, the biological effect monitoring allows an assessment of the existing TBT pollution on the basis of biological effects. Such results are normally more relevant for the ecosystem than pure analytical data. usw.
The storage lipid metabolism of two caridean shrimp species (Crangon crangon and Pandalus montagui) was studied through a combination of enzyme assays, total lipid determination and transcriptome analyses. The initital sampling was carried out in June, July and August 2021 by the research vessel R/V Uthörn. Freshly caught shrimps from the North Sea were measured, weighted and dissected and brought back to the laboratory facilites of the Alfread-Wegener-Institute, Bremerhaven, Germany. Individual midgut glands were weighted to determine the wet mass and freeze-dried. Dry mass was termined and lipids were extracted after Hagen (2000, see in Postel et al. 2000). The total lipid content of individual midgut glands of Crangon crangon and Pandalus montagui was determined gravimetrically. The synthesis of the storage lipid triacylglycerol (TAG) was measured in pooled microsomal fraction of midgut gland tissue of both shrimp species through the activity of the enzyme diacylglycerol acyltransferase (DGAT) at 37 °C in a water bath (McFie & Stone 2011). Here a fluorescent activated fatty acid (NBD-palmitoyl-CoA, 810229 Avanti Polar Lipids) was used. Lipids in the reaction mix were extracted and lipid classes separated on a thin layer chromatography plate. DGAT activity was measured through arbitrary fluorescent units (AFU/min/mg protein) of the correscponding TAG product. Annotated transcriptomes of both species (C. crangon Bioproject: PRJNA479562, NCBI; P. montagui Bioproject PRJNA798226, NCBI) were screened for enzymes involved in the lipid metabolism. Transcripts identified as relevant enzymes using BLAST were translated into amino acid sequences.
Die von der Firma Deutsche Erdöl AG (DEA) geplanten Explorationsbohrungen im Nationalpark Schleswig-Holsteinisches Wattenmeer sind nicht genehmigungsfähig. Grundsätzlich sind nach dem Nationalparkgesetz im Nationalpark Wattenmeer Eingriffe im Sinne des Landesnaturschutzgesetzes, Sprengungen oder Bohrungen verboten. Unter dieses Verbot fallen auch die von DEA beabsichtigen Explorationsbohrungen. Diese Auffassung der Landesregierung wird auch durch ein vom Ministerium in Auftrag gegebenes Rechtsgutachten untermauert, wie Umweltminister Robert Habeck am 19. Dezember 2016 im Rahmen einer Sitzung des Umwelt- und Agrarausschusses mitteilte.