Search results for "Fish"
showing 10 items of 3164 documents
Effects of Biochar on Irrigation Management and Water Use Efficiency for Three Different Crops in a Desert Sandy Soil
2020
This paper aimed at investigating if the application of biochar (BC) to desert sand (DS) from the United Arab Emirates (UAE), characterized by a very poor soil-water retention (SWR) and by a very low value of the maximum water available for crops (AWmax), could positively affect soil water balance, by reducing the irrigation needs (VIRR) and improving the irrigation water use efficiency (IWUE) and the water use efficiency (WUE). The analysis was performed for three crops, i.e., wheat (Triticum aestivum), sorghum (Sorghum vulgare) and tomato (Lycopersicon esculentum). BC was applied to the DS at different fractions, fBC (fBC = 0, 0.091, 0.23 and 0.33). Drip irrigation was adopted as a highly…
Assessment of yield and water productivity of clementine trees under surface and subsurface drip irrigation
2018
Abstract Irrigation systems aimed to optimize water use efficiency in agriculture have become essential due to the increasing water limitations that agriculture is currently facing. Assessment of crop responses to different irrigation systems and strategies are therefore encouraged to find the most efficient options for each specific case. The main objective of this study was to assess the performance of a citrus crop under a surface (SI) and subsurface drip irrigation (SSI) with 7 (SI7, SSI7) or 14 emitters (SI14, SSI14) per plant, as well as a third SS treatment (SSIA), identical to SSI7 but equipped with and additional drip line buried between the tree rows. Evaluations were made in term…
Irrigated agriculture: Water resources management for a sustainable environment
2014
In the last decade, research on irrigation has mainly been aimed at reducing crop water consumption. In arid and semi-arid environments, in relation to the limited water resources, the use of low quality water in agriculture has also been investigated in order to detect their effects on soil physical properties and on crop production. More recently, even the reduction of energy consumption in agriculture, as well as the effects of external factors, climate change and agricultural policies, have been major research interests. All these objectives have been considered in the papers included in this special issue. However, in the last years, approaches aimed at reducing crop water requirements…
Effects of Saline and Deficit Irrigation on Soil-Plant Water Status and Potato Crop Yield under the Semiarid Climate of Tunisia
2019
Water supplies have been decreasing in several semi-arid regions, and it is therefore necessary to adopt irrigation strategies aimed at maximizing water use efficiency. In this paper, the effects of saline and deficit irrigation on water use efficiency and on potato crop response, based on observations of soil and plant water status, were investigated. Experiments were carried out in Central Tunisia, by monitoring potato crop growth during two seasons in four distinct treatments (T1&ndash
Heading which way? Y-maze chemical assays: not all crustaceans are alike
2015
In a world full of chemicals, many crustaceans rely on elaborate olfactory systems to guide behaviors related to finding food or to assess the presence of conspecifics and predators. We analyzed the responses of the isopod Saduria entomon to a range of stimuli by which the animal is likely to encounter in its natural habitat using a Y-maze bioassay. In order to document the efficiency of the experimental design, the same bioassay was used to test the behavior of the crayfish Procambarus fallax whose ability to track odors is well documented. The crayfish performed well in the Y-maze and were able to locate the source of a food-related odor with high fidelity. The isopod S. entomon reacted i…
Nowe stanowisko linderni mułowej Lindernia procumbens na Śląsku Opolskim
2017
Lindernia mułowa Lindernia procumbens (Krocker) Philcox jest rośliną roczną, pojawiającą się w lipcu, kwitnie i owocuje w sierpniu, kończy rozwój późną jesienią wraz z pierwszymi przymrozkami. W Polsce występuje ona bardzo rzadko na rozproszonych stanowiskach, skupionych głównie w dorzeczu górnej i środkowej Odry oraz w dorzeczu górnej Wisły, w miejscach wilgotnych, mulistych lub piaszczystych, na brzegach obu rzek i ich starorzeczy, a także na dnie wysychających stawów hodowlanych, w zbiorowiskach namułkowych z klasy Isoëto-Nanojuncetea. Nowe stanowisko tego gatunku stwierdzono w 2015 roku na dnie wyschniętego stawu hodowlanego w Gąsiorowicach koło Strzelec Opolskich na Śląsku Opolskim
What are the effects of sea warming on the fishing industry?
2019
The paper analyses the impact of Mediterranean Sea warming on some species of small pelagic fish (pesce azzurro) in the Italian fishing industry. In particular, through a time series regression model, the research examines the productivity trend in physical terms of target species of small pelagic fish from 1950 to 2016, considering the Mediterranean Sea Surface Temperatures Anomalies as an indicator of sea warming, and the Western Mediterranean Oscillation index and the North Atlantic Oscillation index as proxies of climatic variability. The research results show an evident link between the reduction of fish availability and sea warming, with potential repercussions on the incomes of the e…
Stranded jellyfish in the lowermost Cambrian (Corduban) of Spain
2021
Ninety discoid structures of big size occurring on a bedding plane of Nemakit-Daldynian to Tommotian sandstones (i.e. Corduban in the Spanish scale of Cambrian stages) from south-western Spain are described. Cross-cutting relationships between discoid structures and associated trace fossils, as well as evidence for penecontemporaneous deformation of sediment laminae below the discoids, permit to interprete these structures as impressions of ancient, soft-bodied marine organisms. Taphonomic, biometric, and morphological studies suggest that they are outer moulds of both sides, subumbrellar and exumbrellar, of ancient jellyfish of hydrozoan coelenterates, whose canals resemble the modern genu…
Welfare status of cage farmed European sea bass (Dicentrarchus labrax): A comparison between submerged and surface cages
2011
Abstract Submersible sea-cages represent an alternative method to standard surface-based cages, and could help solve several production problems that exist in surface-based farming, such as heavy storms, algal and jellyfish blooms and attacks by predators. In this study, we investigated growth, haematological, biochemical and immunological parameters of European sea bass ( Dicentrarchus labrax ) farmed in surface and submersible cages, to compare the physiological status under different rearing conditions. In addition, we evaluated the use of erythrocyte HSP70 levels as a biomarker of fish welfare. The study was conducted in two submerged and two surface cages filled with D. labrax . No sig…
Seasonal zooplankton patterns in a shallow oligotrophic lake: Loch Rusky (Scotland)
1990
The zooplankton taxa and their seasonal distribution are describeb for Loch Rusky, a shallow oligotrophic lake in the central region of Scotland. 15 species were indentified: 11 Rotifera, 2 Cladocera and 2 Copepoda. Only 5 species Polyarthra remata, Keratella cochlearis, Filinia terminalis, Trichocerca sp. and Eudiaptomus gracilis occurred in sufficient numbers to facilitate a description of their seasonal pattern. The annual zooplankton variation was dominated by rotifers for most of the year, but copepods (E. gracilis, Cyclops sp.) only were dominant in the epilimnion during summer. It is presumed that this pattern was the result of the rotifers faster rate of reproduction and higher graz…