Municipal water reservoirs improve urban landscape architecture, providing water for various domestic uses. At the same time, they are under strong human impact affecting water quality and biological conditions. We investigated the level of metal accumulation (Cd, Co, Cr, Cu, Fe, Ni, Mn, Pb and Zn) in sediments as well as mussels Anodonta anatina and Unio tumidus and common reed Phragmites australis collected from 8 sampling sites at Malta Reservoir (Poznań, Poland) just before the complete drainage of the lake in November, 2012. In all investigated samples metal concentrations ranked in decreasing order: Fe>Mn>Zn>Cu>Cr>Ni>Pb>Co>Cd. Accumulation of toxic metals in roots of P. australis was higher than in soft tissues of mussels although it did not exceed phytotoxic levels. Roots of P. australis accumulated high levels of Cr (mean 9.7 μg g-1) and Ni (mean 5.7 μg g-1). U. tumidus accumulated higher concentrations of Cr (mean 1.1 μg g-1) than A. anatina indicating potential use in bioindication of this metal. The present study provides the most recent information on metal content in sediments and biota in Malta Reservoir and, further, suggests that this reservoir is capable of accumulating toxic elements from preceding water bodies (Lake Swarzędz) and surrounding residential areas.
The non-selective, post-emergence herbicides based on glyphosate [N-(phosphonomethyl) glycine] are one of the most widely used pesticides in agriculture, urban areas and forestry. Although there has been documentation on the physical, chemical and toxicological properties of glyphosate, the aquatic toxicity of such formulations still requires assessment and evaluation. In the present study, we describe deliberate use of glyphosate-based herbicide in a bathing area of Lake Lednica (Wielkopolska, Poland) by unknown perpetrators in April, 2011. Glyphosate was detected using gas chromatography mass spectrometry (GC-MS) in the water samples collected from the bathing area at a mean concentration of 0.09 mg dm-3. Aboveground parts of emerged macrophytes (Phragmites australis and Typha latifolia) covering the investigated area were completely withered. Studies of benthic macroinvertebrates revealed no significant differences in taxa number between event (13 taxa) and control (14 taxa) sites although differences in abundance of particular taxa were observed. Significantly lower numbers of Chironomidae (by 41%), Oligochaeta (by 43%), Vivipariae (by 75%), Hirudinae (by 75%), Asellus aquaticus (by 77%), Gammarus pulex (by 38%) and Dreissena polymorpha (by 42%) were found at the glyphosate-treated site. Furthermore, compared to the control, chironomids (Chironomidae) exposed to glyphosate were represented by specimens smaller in length while A. aquaticus only showed large adults. The ranges of glyphosate concentration in the tissues of sampled macroinvertebrates and Phragmites australis organs were 7.3-10.2 μg kg-1 and 16.2-24.7 μg kg-1, respectively. Our study indicates that glyphosate-based herbicides may have adverse effects on aquatic organisms including macroinvertebrates, thus their use in (or nearby) surface waters should be subject to strict limitation.
Prolactin (PRL) is a protein hormone synthesized in and secreted predominantly by lactotroph cells of the anterior pituitary gland. This hormone has been found to stimulate the immune system in animals. Because prolactin secreted in milk by the mother’s body is often insufficient, the administration of exogenous prolactin may significantly contribute to improving the health and growth of piglets. The aim of the study was to determine the dose of prolactin administered to newborn piglets to improve their survivability and growth rate. The study used Biolactin solution, produced on a semi-technical scale by FZNP Biochefa, which was administered per os to newborn piglets at a dose of 0.1, 0.5 and 1.0 mg PRL/kg body weight. NaCl physiological saline was used as a control. The number of piglets born alive, piglet body weight and mortality from birth to 21 and 28 days of age (weaning) were monitored. The study involved 98 litters (1197 piglets), which were divided into 3 experimental and 3 control groups. The experiment showed a positive effect of exogenous prolactin administered to newborn piglets on reducing their mortality and on increasing their birth to weaning growth rate. A dose of 0.5 mg PRL/kg body weight turned out to be optimal.
Flow cytometry (FCM) is routinely used in medical and veterinary diagnostics although it is also widely applied in environmental studies, including phytoplankton investigations. Cyanobacteria are wide-spread photosynthetic microorganisms that attract attention due to their ecology and potential toxicity. Therefore, novel research tools are being applied in their investigation. This paper characterizes FCM as a technique that enables photopigments (chlorophylls and phycocyanin) expressed by cyanobacteria to be excited and their emission to be subsequently detected. This feature not only allows cells to be counted in a rapid manner but also enables a wide range of potential applications in ecological and biochemical studies. The main advantages of FCM, such as rapid, automatic and precise measurements requiring small sample volumes, are also discussed in this paper along with challenges including analyses of filamentous cyanobacteria and signal overlapping. It is expected that FCM will continue to be used in some fields of cyanobacterial studies.