Population Density of Brown Trout (Salmo trutta) in Extremely Dilute Water Qualities in Mountain Lakes in Southwestern Norway

We have examined populations of brown trout in low-conductivity mountain lakes (5.0?C13.7 ??S/cm and 0.14?C0.41 mg/l Ca) in southwestern Norway during the period 2000?C2010. Inlets to the lakes were occasionally even more dilute (2007; conductivity?=?2.9?C4.8 ??S/cm and Ca?=?0.06?C0.17 mg/l). The combination of pH and conductivity was the best predictor to fish status (CPUE), indicating that availability of essential ions was the primary restricting factor to fish populations in these extremely diluted water qualities. We suggest that conductivity <5 ??S/cm is detrimental to early life stages of brown trout, and subsequently that there are lakes in these mountains having too low conductivity to support self-reproducing trout populations. Limited significance of alkalinity, Ca, Al, and color suggests that effects of ion deficit apparently overruled the effects of other parameters.     

Sprouting Dynamics of Bunias orientalis

Journal of Plant Diseases and Protection - Bunias orientalis is a highly vigorous weed and the powerful taproot makes control difficult. Taking action against unwanted plant species at the...     

Application of sorbents in different soil types from small arms shooting ranges for immobilization of lead (Pb), copper (Cu), zinc (Zn), and antimony (Sb)

Journal of Soils and Sediments - Soil contamination of ammunition residues at shooting ranges for small arms may be followed by leaching of lead (Pb), copper (Cu), zinc (Zn), and antimony (Sb)....     

Probing structural periodicity (annual ring size) in Scots pine by NMR profiling

The water distribution along a direction normal to the annual rings of a water-saturated sapwood sample from Scots pine (9 mm of length) was determined using NMR one-dimensional imaging. The NMR profiles were obtained at a low-field NMR instrument using pulsed field gradients in Hahn echo experiments. Using a gradient pulse of 60 G/cm, a spatial resolution of 12 μm along the axis was obtained. A subsequent Fourier analysis of the signal intensity along the specified direction enabled the size distribution of the annual rings together with the relative amount of water within the rings to be estimated. The technique is a non-damaging way to determine the annual ring profile in wood, and can be further developed as a mobile technique for annual ring profiling of whole trees.     

Economic dependence on forest resources: A case from Dendi District, Ethiopia

This paper examines variation in dependence on forest resources among rural households in Chilimo, Ethiopia, and the income-equalizing effects of such resources. Data were collected through a systematic questionnaire survey of 102 households, randomly selected from two peasant associations in the area. Forest income contributed 39% of the average household income, roughly equal to agriculture, which contributed 40%. Forest income was more important than all other income sources combined for the poorest 40% of households and contributed more to household income than agriculture for 65% of households. While forest income represents 59% of the total household income for the poorest quintile, the contribution drops to 34% for the wealthiest quintile. On the other hand, the rich households derive a larger absolute income from forest resources than the poor households. Forest resources have an important income-equalizing potential among the rural households. Reduced access to forest resources would greatly affect the welfare of the rural population and increase wealth differentiation among rural households in the study area.     

Biomaterials and Bioactive Natural Products from Marine Invertebrates: From Basic Research to Innovative Applications

Aquatic invertebrates are a major source of biomaterials and bioactive natural products that can find applications as pharmaceutics, nutraceutics, cosmetics, antibiotics, antifouling products and biomaterials. Symbiotic microorganisms are often the real producers of many secondary metabolites initially isolated from marine invertebrates; however, a certain number of them are actually synthesized by the macro-organisms. In this review, we analysed the literature of the years 2010–2019 on natural products (bioactive molecules and biomaterials) from the main phyla of marine invertebrates explored so far, including sponges, cnidarians, molluscs, echinoderms and ascidians, and present relevant examples of natural products of interest to public and private stakeholders. We also describe omics tools that have been more relevant in identifying and understanding mechanisms and processes underlying the biosynthesis of secondary metabolites in marine invertebrates. Since there is increasing attention on finding new solutions for a sustainable large-scale supply of bioactive compounds, we propose that a possible improvement in the biodiscovery pipeline might also come from the study and utilization of aquatic invertebrate stem cells.     

Infectious pancreatic necrosis virus (IPNV) serotype Sp is prevalent in Turkish rainbow trout farms

Infectious pancreatic necrosis virus (IPNV) is a common pathogen of rainbow trout (Oncorhynchus mykiss) in Turkey. We found that 455 of 1,676 sample pools tested were IPNV positive. Positive samples were found in all geographical regions where sampling was conducted. Sequence and phylogenetic analyses of VP2 from 30 isolates representing all regions showed that the viruses were highly similar in sequence and grouped within Genogroup 5 (serotype Sp‐A2). No correlations between sequences, sampling sites or geographical origins were identified. Although clinical disease was evident in several farms, analyses of the amino acid sequence of VP2 showed that all virus strains harboured the P₂₁₇T₂₂₁ motif, assumed to be associated with low virulence. We conclude that IPNV is prevalent in Turkish rainbow trout farms and that the viruses are very homogenous and likely to be of European origin. Frequent exchange of eggs and live fish within the farming industry may explain the homogeneity of the IPNV.     

Assessment of seafood processing wastes as alternative sources of Selenium in plant production

Abstract

In some parts of the world, the soil selenium (Se) content is too low to ensure the Se level recommended for human or animal consumption in the crops produced. In order to secure a desired concentration of Se in crops, Se has been applied as mineral fertilizer to agricultural fields. Since only a minor part of the inorganic Se applied is utilized by plants and small increases in Se concentrations in, e.g., drinking water, may be toxic, the method is somewhat controversial. As an alternative to Se-enriched mineral fertilizer, different seafood-processing wastes have been examined as a source for Se in crop production. Both in greenhouse pot experiments and field trials the Se in seafood waste was not plant-available during the first growing season. There was no significant difference between the Se concentration in wheat growing in soil without added Se and in soil receiving Se from seafood waste in amounts ranging from 0.9 to 9 g ha^?1. Neither was any residual effect of Se in seafood waste seen during a second year growth period. Thus, seafood-processing waste cannot be regarded as a potential source of Se in crop production. Possible mobilization of formerly applied Se, as seafood-processing waste or Se enriched mineral fertilizer due to changes in soil redox conditions were examined in a leaching experiment. The mobility of formerly applied Se was generally very low, but the results indicated that under permanently wet soil conditions leaching of Se may occur in plant dormant periods in soils with low organic matter content and high pH.     

Melanized focal changes in skeletal muscle in farmed Atlantic salmon after natural infection with Piscine orthoreovirus (PRV)

Melanized focal changes in skeletal muscle of farmed Atlantic salmon (Salmo salar) are a major quality problem. The aetiology is unknown, but infection with Piscine orthoreovirus (PRV) has been associated with the condition. Here, we addressed the pathogenesis of red and melanized focal changes and their association with PRV. First, a population of farmed fish (PRV‐negative prior to sea transfer) was sequentially investigated throughout the seawater period. The fish were autopsied and tested for PRV infection. Muscular changes were described by macroscopy and histology, and a classification system was established. Second, in an experimental infection trial, PRV was injected intramuscularly to induce changes. The farmed fish was gradually infected with PRV. Red focal changes occurred throughout the observation period with a low prevalence regardless of PRV status. Melanized changes were highly diverse and their prevalence increased during the trial. Changes of low macroscopic grade and histological category were more prevalent in PRV‐negative fish. Diffuse granulomatous melanized changes only occurred after PRV infection. No muscular changes were observed in the experimentally challenged fish. Our studies do not indicate that PRV infection causes red focal changes, but seems important in the development of granulomatous melanized changes.