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In fast-flowing streams, caddisfly larvae are responsible for processes that collectively determine the efficiency with which the detritivore community is able to decompose autochthonous and allochthonous detritus. This ecosystem function ensures high water quality and represents a precious service for resident rural communities. The analysis of δ13C and δ15N in eight caddisfly taxa from a mid-mountain stream evidenced a remarkable complementarity in their feeding preferences. An aquatic moth mimicking the caddis mode of life was also included in the survey and its feeding niche appeared to be in between the one of caddis taxa. Moderate niche overlap was interpreted in terms of low functional redundancy, implying that in case of a reduction in diversity, no taxon could be a perfect substitute for another, with a loss of functional efficiency. Low redundancy could be caused by niche segregation due to avoidance of competition/interference between taxa. The broad range of δ13C and δ15N described in this study warns against attributing single δ13C and δ15N to Trichoptera as a group, or even to single families. These results contribute to the still poorly known distribution of East African caddisflies and to the characterisation of feeding preferences of Afrotropical trichopteran larvae. [ABSTRACT FROM AUTHOR]

1. A survey of eight local earthen hand-dug ponds located within the freshwater swamps of a Niger Delta area (southern Nigeria) was conducted over a period of 3 months. A total of 4,313 fishes representing 19 species from 12 families were recorded.

One of the biggest challenges in understanding and managing biological invasions is the identification of the routes of introduction. This information is often incomplete because of unnoticed, unreported and, sometimes, illegal translocations. Reports on the introduction of the red swamp crayfish (Procambarus clarkii) into Europe describe that it was introduced for the first time to southern Spain (1973 and 1974) from Louisiana; from there, it rapidly spread throughout several European countries. While other importation events and pathways of introduction have been suggested in the literature, there is no evidence that these led to wild populations in Europe. Our present study suggests two additional introduction routes into Europe from non-European areas where the red swamp crayfish had previously been reported. By using mtDNA, we found a shared haplotype between the Lake Naivasha in Kenya and Western Europe, as well as another between either western United States or Asia, and Malta. These findings support historical reports found in the literature for the former case and also point towards pet trade as driver of new introductions for the latter, thus highlighting the complex introduction history of the red swamp crayfish populations in Europe.

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Next to cetaceans and megafishes, freshwater turtles are the most iconic endangered freshwater species.A detailed questionnaire survey conducted with more than 100 individuals from fishing communities in northern Vietnam was used to investigate the current status of Southeast Asian turtles and provides new hope concerning the survival of Rafetus swinhoei, for which recent official records in the wild are limited to a single individual in Vietnam.The survey included the entire Vietnamese portion of the Da River in Hoa Binh and Son La provinces, as well as the Chu and Ma river system in Thanh Hoa Province, as they are the last sites where the world's rarest and largest Asian softshell turtle has been seen. The questionnaire, conducted in Vietnamese, focused on demographic details, fishing intensity and gear, the status of fishing grounds, and the frequency of interaction with turtles.The great majority of fishers could recognize different turtle species from photographs and describe their preferential breeding habitats; not all knew that they are protected. A few confirmed that more than once each year they still encounter freshwater turtles during their fishing activities.This survey provides detailed information on sites where freshwater turtles are still seen in northern Vietnam and broadens our hope that wild individuals of the extremely rare R. swinhoei may still be present in the remaining riparian wetlands of these biodiverse, dammed, and controlled river basins in North Vietnam. [ABSTRACT FROM AUTHOR]

Reports of global declines in animal populations are now numerous and also include snakes, a group of animals now widely regarded as bio-indicators. A prerequisite for any conservation management plan to protect or restore snake populations requires a data base that provides insight into population composition and changes. However, snakes are well known to be particularly difficult to quantitatively sample due to their secretive and elusive nature, and hence accumulating an adequate database for analysis requires long-term field studies that involve intensive searches. Populations of four snake species, Zamensis longissimus, Natrix helvetica, Vipera aspis and Hierophis viridiflavus living in two suburban areas of Rome with different extents of habitat alteration (deforestation), Vejo, a less altered site, and Tor Bella Monaca, a high altered site, have been monitored, but with interruptions since 1995. The results indicated that H. viridiflavus was the commonest species at both sites. Male bias was found in all four species but especially in Z. longissimus and V. aspis with detection of juveniles greatest in H. viridiflavus and N. helvetica. Snout to vent lengths (SVL) of H. viridiflavus and Z. longissimus, which were present at both sites, were greater at the less degraded habitat of the two study localities. Community metrics indicated that the degraded habitat had lower species richness, evenness, Shannon and Simpson diversity indices, but a higher dominance index. Recapture frequencies of snakes recaptured either once or multiple times were in general greater at Vejo. The highest population densities were found in H. viridiflavus, followed by V. aspis and N. helvetica, which were similar. However, long term trends in densities show declines in V. aspis and N. helvetica between 1995 and 2019. Population densities were in good agreement with density estimates found in previous studies of snakes in more natural habitats. [ABSTRACT FROM AUTHOR]

The forest hingeback tortoises Kinixys homeana and Kinixys erosa are two of the most declining African chelonians. Although the population size trends of these species have received attention in some specific areas of West Africa, an overall perception of their declining trajectories are still largely unexplored. We used interviews with rural people (hunters, farmers and snail gatherers) in order to explore the general perception that these experienced people have on the population trends of these threatened tortoises. Overall, we interviewed over 2000 people in three West African countries (Côte d'Ivoire, Togo and Nigeria), which mostly supported the notion that these tortoises are heavily declining in Togo and Nigeria, but less so in Côte d'Ivoire. In addition, many respondents suggested that snail gatherers are the main providers of tortoises to the bushmeat trade. Indeed, our market surveys revealed that, in Nigeria, there was a significantly positive correlation between number of wild snails traded by individual sellers and numbers of sold tortoises in their 'shops'. [ABSTRACT FROM AUTHOR]

The bushmeat trade in West and Central Africa embraces a broad range of ecological, economic, and conservation issues. To date, most studies have focused on the economic and conservation aspects of the bushmeat trade, with less emphasis on the ecological implications of wildlife extraction. Here, we analysed available literature on the bushmeat trade in 5 countries in west and central Africa exploring ecological traits such as niche width breadth and trophic position of the species involved, and habitats impacted. We also examine temporal changes over a 40-year period. Our results confirm that mammals dominated the trade in all studied areas and time periods, in terms of (i) number of species, (ii) number of traded individuals, and (iii) overall biomass. Herbivores were the most common trophic animal guild traded. Forest-specialists were the most abundant in the trade, and in riverine habitats reptile biomass almost as important as mammals. Overall, the most traded species and individuals were non-threatened according to the IUCN Red List. Our temporal analyses indicated that more habitat generalist and water-linked species were traded during 1971 - 2000, but forest dependent taxa predominated during the following decade (2001 - 2010). Additionally, the number of individuals of large-bodied herbivores rose relative to small and medium-sized ones, whereas traded biomass over time increased: (a) in the consumption of super-predators; (b) of large-bodied herbivores, but (c) a significant decrease in consumed biomass of medium and small-bodied herbivores. We suggest that the observed trends may suggest an imminent reduction of large-bodied herbivores and, as a cascade effect, also of super-predators in African moist forests. [ABSTRACT FROM AUTHOR]

Simple Summary: Phosphate solubilizing microorganisms (PSMs), a large microflora that mediate bioavailable soil P, play a critical role in soil by mineralizing organic P, solubilizing inorganic P minerals, and storing large amounts of P in biomass. Given that the basic soil P forms and orthophosphate levels can be mediated by PSMs, we conclude that PSMs also play a critical role in the soil P cycle. The present review summarizes the comprehensive and recent understanding about the roles of PSMs in P geochemical processes. Phosphorus (P) is a vital element in biological molecules, and one of the main limiting elements for biomass production as plant-available P represents only a small fraction of total soil P. Increasing global food demand and modern agricultural consumption of P fertilizers could lead to excessive inputs of inorganic P in intensively managed croplands, consequently rising P losses and ongoing eutrophication of surface waters. Despite phosphate solubilizing microorganisms (PSMs) are widely accepted as eco-friendly P fertilizers for increasing agricultural productivity, a comprehensive and deeper understanding of the role of PSMs in P geochemical processes for managing P deficiency has received inadequate attention. In this review, we summarize the basic P forms and their geochemical and biological cycles in soil systems, how PSMs mediate soil P biogeochemical cycles, and the metabolic and enzymatic mechanisms behind these processes. We also highlight the important roles of PSMs in the biogeochemical P cycle and provide perspectives on several environmental issues to prioritize in future PSM applications. [ABSTRACT FROM AUTHOR]

Suspended sediments collected during rain events were analysed to assess the maximum potential bioavailability of particulate phosphorus (PP). Physical (separation by particle size) and chemical (sequentialextraction) fractionation techniques were applied. Time differentiated sampling during rain events revealed that changes in the concentrations of soluble and particle bound phosphorus, and in the proportionof different PP phases, are due to the changing contribution of various sources of runoff and to flow related variations in particle size. Size fractionation and the extraction of PP phases, can help to distinguish resuspended sediments from sediments coming directly from outside the channel. In light of a former study, investigating PP sedimentation and transformations within the sediments of Lake Sempach, our results lead to the conclusion that, at least 25% (particulate inorganic and reductive soluble P) and at most 70% of the allochthonous PP supply transported during a single rain event, may become bioavailable after early diagenesis in the lake sediments. The uncertainty is due to the unknown time span necessary for the diagenesis, at the lake sediment surface, of particulate organic phosphorus of allochthonous origin. [ABSTRACT FROM AUTHOR]

Background assessment is crucial in setting remediation and management goals, in identifying contamination trends and in providing screening tools for the selection of contaminants of concern. Legal requirements and guideline documents place great emphasis onto the establishment of background levels. This contribution discusses background estimates for metals and organics in relation to bioavailability and to its potential impact onto living systems. Methods for defining background in Environmental Risk Assessment are provided by the US EPA and by the Dutch Added Risk Approach. Cited case studies, taken from projects carried out in Italy and abroad, show that practical approaches vary significantly. A standardised database of soil, sediment and water background levels for different contaminants, as well as a more comprehensive guideline of background assessment, are urgently needed.