In spite of their conservation importance, only a fraction of lakes and streams globally – including their catchments – are currently covered by conservation areas. To identify conservation gaps, assessing the spatial distribution of biodiversity in relation to conservation areas is a promising approach. A gap‐analysis approach was used to evaluate the protection status of the habitats of two endangered freshwater mussel species, Margaritifera margaritifera (Linnaeus, 1758) and Unio crassus (Philipsson, 1788), in the Federal State of Bavaria, Germany. First, ecological niche models (ENMs) were developed for both mussel species based on presence‐only data in order to identify suitable habitats. Second, binary maps of suitable and unsuitable habitats for the species were used to compare different categories of currently protected areas in a gap analysis. The ENMs for M. margaritifera revealed a spatially restricted distribution with good model performance, whereas the spatial distribution of U. crassus was wider and the model performance was weaker. For M. margaritifera, a higher percentage of suitable habitat is already under some sort of protection, whereas for U. crassus only half of the suitable habitats are under protection. The results suggest that suitable habitats of both species are not sufficiently protected. More effective conservation of M. margaritifera and U. crassus requires separate management: increasing the respective protection categories of already protected habitats of M. margaritifera and incorporating an increased area of suitable habitats under legal protection for U. crassus.

The aim of the current research is to develop a gear transmission fluid based on water and plant extract. Up to now, mineral or synthetic oils are used as lubricants in most gear drive applications. These oils are made of fossil raw materials and are non-biodegradable. Lately, there have been some efforts made to develop lubricants as an alternative to conventional lubrication systems such as triglycerides from native oils or synthetic esters. These lubricants are more biodegradable than mineral oils but also show some difficulties during performance like saponification. Within a former research project, the company Carl Bechem GmbH and the Fraunhofer Institute for Process Engineering and Packaging IVV developed a cutting fluid based on water and plant extract. With a model sample of this fluid, which also contained gear typical additives, preliminary experimental investigations for a current research study were conducted. The results confirmed the general suitability of this water-based lubricant for gear drives under certain operating conditions. Using water as lubricants can lead to some improved characteristics due to the very high thermal conductivity and the reduced friction. This paper aims to point out the benefits of using water-based lubricants, share the results of some preliminary experimental investigations on a fluid sample based on water and plant extract, and discuss the challenges, which one has to overcome during the development of such new lubricants.

Gear pairings often run under very high loads. That can result in different kinds of failure modes limiting their lifetime. Many of the known gear failure modes are tribologically influenced. Especially for gear pairs running with lower circumferential speeds or with different surface hardness, (continuous or slow speed) wear is often the lifetime limiting factor. Slow speed wear appears continuously over a longer period of runtime. In many cases, such applications are lubricated with greases. Since the standardized calculation methods (e.g. ISO 6336) do not cover any determination of wear, one common way to predict the wear lifetime is the calculation method according to Plewe. In the associated Plewe diagram the worn off amount of material is correlated to the minimal lubricant film thickness in the tooth contact. The wear intensity decreases for higher film thicknesses. However, this method has certain limits for greases, because the film thickness of a grease, its bleed oil and the base oil is not necessarily the same. Additionally, the consistency and the flow properties have to be considered, because they influence the lubrication supply mechanism (circulating or channeling). Under certain circumstances channeling could be predominant. Although in theory a grease should build a thicker lubricating film than its base oil, experimental investigations have shown higher wear rates in comparison to oil lubrication.

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The Chinese pond mussel, Sinanodonta woodiana, is non-native to European freshwater systems. Originating from Asia, it was brought to Europe in the 1970s and is now spreading across many countries. Management of the species is currently limited by a lack of information on the actual distribution and population characterisation of S. woodiana as well as on the co-occurrence of native mussels potentially resulting in competition. For this paper, we examined nine water systems in the German federal state of Bavaria with randomly observed and anecdotally reported S. woodiana occurrences. We recorded the density and biomass of S. woodiana and of the co-existing mussel species as well as the habitat characteristics. We found S. woodiana in eight water systems, co-existing with other native and invasive mussel species in seven of them. The distribution of S. woodiana was geographically widespread throughout Bavaria, indicating great invasion potential. In one fish pond, S. woodiana was the only mussel species occurring with the highest mean biomass (1286.0 ± 1067.7 g m−2) and with the biggest specimen (25.0 cm and 1616.0 g). The wide range of habitat variables matched the expectation of a wide ecological niche for the species. This study provides evidence that S. woodiana has already become established in many water systems in Bavaria, with fish ponds and fisheries management practises being a likely vector. To counteract this species and to conserve native mussel species, it is important to implement effective legislation, to take measures to eradicate this invasive mussel transnationally, and to raise public awareness.