Consequences of experimentally elevated yolk testosterone levels for intra- and inter-sexual selection in canaries

Hormones of maternal origin transferred to the eggs of oviparous species have been shown to significantly affect offspring development. Furthermore, there is now increasing evidence that these effects may last into adulthood. This underlines the persistence of yolk hormone-mediated maternal effects as well as their trans-generational potential as these changes may involve fitness-related traits such as mate choice behaviour, reproductive traits and longevity. Here, we tested the potential of yolk testosterone to affect sexual selection by experimentally increasing the yolk testosterone levels via egg injections. We focused on two central axes of sexual selection, male–male competition for access to a female (intra-sexual selection) and female mate choice behaviour (inter-sexual selection), using canaries (Serinus canaria) as a model species. Neither male agonistic behaviour nor access to the opposite sex, as measured in staged male–male encounters in the presence of a female, were affected by experimentally elevating yolk testosterone levels. We did not find any evidence for effects on female mate choice behaviour either, given the lack of significant effects on mate choice activity, consistency in female mate choice or choosiness. In conclusion, our results indicate that the consequences of yolk testosterone for sexual selection through changes in behavioural traits, which are expressed during pair formation or male–male competition, are probably limited.     

Ecological limitations and appropriation of ecosystem support by shrimp farming in Colombia

Shrimp farming in mangrove areas has grown dramatically in Asia and Latin America over the past decade. As a result, demand for resources required for farming, such as feed, seed, and clean water, has increased substantially. This study focuses on semiintensive shrimp culture as practiced on the Caribbean coast of Colombia. We estimated the spatial ecosystem support that is required to produce the food inputs, nursery areas, and clean water to the shrimp farms, as well as to process wastes. We also made an estimate of the natural and human-made resources necessary to run a typical semiintensive shrimp farm. The results show that a semiintensive shrimp farm needs a spatial ecosystem support—the ecological footprint—that is 35–190 times larger than the surface area of the farm. A typical such shrimp farm appropriates about 295 J of ecological work for each joule of edible shrimp protein produced. The corresponding figure for industrial energy is 40:1. More than 80% of the ecological primary production required to feed the shrimps is derived from external ecosystems. In 1990 an area of 874–2300 km² of mangrove was required to supply shrimp postlarvae to the farms in Colombia, corresponding to a total area equivalent to about 20–50% of the country’s total mangrove area. The results were compared with similar estimates for other food production systems, particularly aquacultural ones. The comparison indicates that shrimp farming ranks as one of the most resource-intensive food production systems, characterizing it as an ecologically unsustainable throughput system. Based on the results, we discuss local, national, and regional appropriation of ecological support by the semiintensive shrimp farms. Suggestions are made for how shrimp farming could be transformed into a food production system that is less environmentally degrading and less dependent on external support areas.     

Effects of choice of baseline on the uncertainty of population and biodiversity indices

Environmental and Ecological Statistics - Many monitoring programs provide annual indices of relative change over time in some quantitative measure of ecological status, such as population...     

Temporal trends in opportunistic citizen science reports across multiple taxa

Opportunistic reporting of species observations to online platforms provide one of the most extensive sources of information about the distribution and status of organisms in the wild. The lack of a clear sampling design, and changes in reporting over time, leads to challenges when analysing these data for temporal change in organisms. To better understand temporal changes in reporting, we use records submitted to an online platform in Sweden (Artportalen), currently containing 80 million records. Focussing on five taxonomic groups, fungi, plants, beetles, butterflies and birds, we decompose change in reporting into long-term and seasonal trends, and effects of weekdays, holidays and weather variables. The large surge in number of records since the launch of the, initially taxa-specific, portals is accompanied by non-trivial long-term and seasonal changes that differ between the taxonomic groups and are likely due to changes in, and differences between, the user communities and observer behaviour. Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01550-w.     

Ecology,evolution, and management strategies of northern pike populations in the Baltic Sea

Baltic Sea populations of the northern pike (Esox lucius) have declined since the 1990s, and they face additional challenges due to ongoing climate change. Pike in the Baltic Sea spawn either in coastal bays or in freshwater streams and wetlands. Pike recruited in freshwater have been found to make up about 50 % of coastal pike stocks and to show natal homing, thus limiting gene flow among closely located spawning sites. Due to natal homing, sub-populations appear to be locally adapted to their freshwater recruitment environments. Management actions should therefore not involve mixing of individuals originating from different sub-populations. We offer two suggestions complying with this advice: (i) productivity of extant freshwater spawning populations can be boosted by modifying wetlands such that they promote spawning and recruitment; and (ii) new sub-populations that spawn in brackish water can potentially be created by transferring fry and imprinting them on seemingly suitable spawning environments.     

Addressing the challenges of tetracycline analysis in soil: extraction, clean-up, and matrix effects in LC-MS

An optimized extraction and clean-up method for the analysis of chlortetracycline, doxycycline, oxytetracycline, and tetracycline antibiotics in soil is presented in this work. Soil extraction using different solvents was performed, but the use of a 50 : 50 (v/v) methanol : acetate buffer (pH 8) solvent mixture in a pressurized liquid extraction (PLE) system proved to give the best extraction efficiency and reproducibility. The effect of soil composition on the PLE extraction efficiency was also examined, and results indicated that recovery data for one soil is not necessarily consistent with other soil types containing different compositions of clay and organic matter content. The percent recoveries of the optimized PLE method varied between the soils and ranged from 22-99%, depending on soil type, and more specifically clay content. In addition, the extent of ionization suppression caused by co-extracted humic acids was examined in an ion trap mass spectrometer (MS), and a single quadrupole MS. It was found that under positive electrospray ionization, the single quadrupole MS was less susceptible to ionization suppression than the ion trap MS. Therefore, various sample clean-up procedures were evaluated to selectively reduce the amount of co-extracted humic acids in the soil extracts. The most effective clean-up was obtained from the use of StrataX sorbent in combination with a strong anion exchange cartridge.     

Chemical composition determines the bioenergy potential of food waste from pre- and post-production

Journal of Material Cycles and Waste Management - The chemical characterization of the food waste allowed to discriminate between the pre-preparation and post-preparation residues from a...     

Varieties of market-based policy: Instrument choice in climate policy

Since the 1970s, European and US regulators have used different varieties of market-based environmental policy, which are rooted in competing types of liberalism: price instruments and quantity instruments, respectively. In the case of climate change, however, the EU and the US have converged on hybrid policy mixes. This convergence in instrument choice is examined in two cases: the emergence of the EU Emission Trading Scheme, i.e. the import of quantity regulation to the EU; and the creation of California’s feed-in tariff, i.e. the import of price regulation to the US. Increasing convergence in instrument choice is the result of international diffusion through learning and shifting domestic coalitions. This demonstrates that the two varieties of market-based environmental policy increasingly blend, and how policy import is driven by domestic government–producer coalitions rather than by policy-maker ideas of ‘best practice.’     

Adaptation of the Daphnia sp. acute toxicity test: miniaturization and prolongation for the testing of nanomaterials

Manufacturing of nanomaterials (NMs) is often complex and expensive, and their environmental risks are poorly understood or even unknown. An economization of testing NMs is therefore desirable, which can be achieved by miniaturizing test systems. However, the downsizing of test vessels and volumes can enlarge the surface/volume ratio (SVR) which in turn can affect the bioavailable concentration of adsorbing substances like NMs. The present study focused on the miniaturization of the acute toxicity test with Daphnia magna. The adaptations were verified with three reference substances, the non-adsorbing potassium dichromate (K₂Cr₂O₇) and as potentially highly-adsorbing substances silver nanoparticles (AgNPs) and silver nitrate (AgNO₃). The miniaturized test was conducted in 24-well microtiter plates (MT) and simultaneously compared to the OECD standard test (ST). Furthermore, the test duration was prolonged from 48 to 96 h since NMs tend to show effects only after extended exposure. The toxicity of K₂Cr₂O₇ and AgNPs continued to increase within the prolonged test span. The test comparisons with K₂Cr₂O₇ did not reveal any significant differences between ST and MT. AgNO₃ toxicity was significantly decreased in MT compared to ST due to the enlarged SVR. The toxicity of AgNPs in MT after 24 h was equal to ST. Contrary to our expectations an exposure longer than 24 h resulted in an increase of AgNP toxicity in MT, possibly due to enhanced dissolution of silver. Microtiter plates are appropriate alternative test vessels for the Daphnia sp. acute toxicity test; thus, its miniaturization is feasible. The enlarged SVR has to be taken into account since it can affect the toxicity of potentially adsorbing substances. Furthermore, the standard test duration of 48 h might underestimate the toxicity of many substances, especially of NMs.