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Abstract Freshwater fishes are among the most threatened groups of vertebrates, with 39% of all European fish species facing extinction. Herein, we provide a comprehensive analyses of historical data as well as fish monitoring data from 1989 through 2013 from Bavaria, Germany. The results of this study indicate that the most pronounced species-turnover already had occurred before the 1990s. Severe loss of species (21 out of 69 species lost until 1990s), decrease in spatial distribution (51 species, 27 reduced to <50% of historical distribution), decrease of abundance, shifts towards potamal species and the establishment of novel communities due to increasing colonization with non-native species was evident. Declines were strongest for gravel-spawning species of the hyporhitral and epipotamal in medium-sized and large rivers (e.g. grayling (Thymallus thymallus), nase (Chondrostoma nasus), barbel (Barbus barbus)), suggesting that effects of increasing water temperatures and increased fine sediment loads probably strongly contribute to the decline of those species. Our results generally confirmed the validity of current conservation status for most species, but also identified species (dace (Leuciscus leuciscus), chub (Squalius cephalus), trout (Salmo trutta) , minnow (Phoxinus phoxinus), nase and barbel) and habitats (medium-sized and large rivers) that deserve higher priority in conservation management. More consistent sampling of the same sites over years and a quantitative monitoring of environmental impact factors in appropriate spatial and temporal resolution is crucial to allow a future prioritization in freshwater fish conservation. Highlights • Freshwater fish are among the most threatened groups of vertebrates. • We compare fish communities from historic data and monitoring data from 1989 to 2013. • We detected a severe loss of species and decrease in distribution and abundance. • An establishment of neobiota resulting in novel community structures was evident. • We identified species and habitats that deserve higher priority in conservation. [ABSTRACT FROM AUTHOR]

The Anthropocene deposits of England, here regarded as those formed after ∼1950 CE, are now extensive, take various forms, and may be characterized and recognized by a number of stratigraphic signals, such as artificial radionuclides, pesticide residues, microplastics, enhanced fly ash levels, concrete fragments and a novel variety of ‘technofossils’ and neobiotic species. They include the uppermost parts of both ‘natural’ deposits such as the sediment layers formed in lakes and estuaries, and more directly human-made or human-influenced ones such as landfill deposits and the ‘artificial ground’ beneath urban areas and around major constructions. ‘Negative deposits’ include the worked areas of quarries and regions such as the English Fenland, where thick peat deposits have ablated to leave a strongly modified underlying landscape, and extend beneath into the subterranean realm as mine workings, metro systems and boreholes. The production of these is still rapidly increasing and evolving in character, while the early signs of global change, such as warming, sea level rise, and modifications to biotic assemblages, are beginning to further modify the emerging geology of this new phase of Earth history. [ABSTRACT FROM AUTHOR]

Marine environments are threatened by biological invaders that are transported via ship hulls or ballast water at increasing rates around the globe. Most management strategies that should prevent or reduce the impact of alien species include prevention and eradication programs that both rely on an early detection of introduced species. Early detection requires an up to date inventory of present species and efficient monitoring programs to identify newly arrived species. This study surveyed potential invasion ‘hot spots’ in the coastal waters of the central Wadden Sea, including commercial ports (‘port’ stations) as well as fairways, roads, groynes and oyster reefs (‘Wadden Sea’ stations) to establish lists of macrobenthic species as baseline for future monitoring. In the ports we applied simultaneously the HELCOM/OSPAR protocol (H/O) and a regional established rapid assessment (RA) to enable the evaluation of the effectiveness and comprehensiveness of both methods. While the RA is mainly based on the visual screening of species in easy accessible habitats in the field, the H/O includes an extensive sampling by operation of scientific divers boat times and a 4-times higher time effort for sample processing. We identified among all sites 273 species including 37 alien species. The fauna was composed of 210 native and 32 alien species, while the flora was composed of 26 native and 5 alien species. The ports were a diverse habitat with species numbers from 65 to 109. At the Wadden Sea stations, exclusively monitored by the less extensive RA, only half of the species numbers (36–66 species) were detected. However, on the oyster reefs the relative occurrence of alien species compared to natives was similar to the ports and one oyster reef (Nordland) even had the highest ratio (25%, 14 species) of alien species of all investigated sites. The H/O protocol identified 179 species compared to 114 species identified by the RA. Regarding alien species, the H/O provided 85% of alien species, the RA only 67%. Especially with regard to the actual discussion on harmonized monitoring protocols within the Northeast Atlantic and Baltic regions, we recommend that future port surveys should apply the more extensive H/O protocol, since restrictions to the RA decrease drastically the chance of an early detection of alien species. We also recommend complementing the survey of ports with natural invasion ‘hot spots’ like the oyster reefs by rapid assessment. This combined monitoring design secures a significant increase in the early detection of alien species as demonstrated in our study. [ABSTRACT FROM AUTHOR]

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