Search results for " fisheries."
showing 10 items of 1015 documents
The role of two non-indigenous serpulid tube worms in shaping artificial hard substrata communities: case study of a fish farm in the central Mediter…
2019
Understanding the spread and establishment of non-indigenous species (NIS) is one of the primary areas of focus in bioinvasion science and is essential for generating appropriate management strategies in aquaculture. Here we investigated the role of 2 non-indigenous serpulid tube worms (Hydroides elegans and H. dirampha) in shaping the hard substrata communities around a fish farm in the Strait of Sicily over 1 yr (June 2014-June 2015), at 3 mo intervals (September and December 2014, March and June 2015). The mean density values of serpulids were significantly different at each sampling time. The density of serpulids on submerged panels showed a peak in spring (March 2015, after 9 mo) and d…
Spectrofluorimetric study of dissolved organic matter in River Salaca (Latvia) basin waters
2012
Dissolved organic matter (DOM) in surface waters influences mineral weathering, nutrient cycling, aggregation of particulate matter and photochemical reactions in waters and aquatic communities. In this study, the effectiveness of UV and fluorescence measurements in distinguishing the origin of DOM and processes within the river basin were analyzed using the River Salaca basin as an example. The basin of River Salaca is characterized by low anthropogenic pressure, however, the water color during the last few decades has increased (an effect known as brownification). As tools to study the composition of dissolved organic substances in waters of the River Salaca and its tributaries the use of…
Invasive crayfish increase habitat connectivity: a case study in a large boreal lake
2013
Several studies have shown that distinct compartments of lake ecosystems are coupled via transportation of organic matter, nutrients and energy across habitat boundaries. Here we evaluate the potential of the invasive signal crayfish (Pacifastacus leniusculus (Dana)) to modify energy pathways in large boreal lakes. Using a stable isotope mixing model and calculation of the isotopic niches we estimated the contribution of different food sources to the diets of crayfish captured from different habitats, and from that inferred their potential to transport energy across the littoral-profundal gradient. The crayfish caught from the littoral area utilized mainly littoral food sources, whereas the…
Reproductive features of the deep-water rose shrimp, Parapenaeus longirostris (Crustacea: Penaeidae), in the Strait of Sicily
2010
The deep‑water rose shrimp, Parapenaeus longirostris (Lucas, 1846), is one of the most valuable and heavily exploited demersal species of the Mediterranean bottom trawl fisheries. The basic life traits of this shrimp, in particular its reproductive aspects, are regularly monitored during experimental trawl surveys carried out in the Mediterranean Sea. Gonadic condition and maturity status for estimating the size at onset of sexual maturity are commonly assessed in females, using macroscopic color scales, histologically validated only in a few geographical areas. In this study, histological analyses were performed on rose shrimps collected from a trawl survey carried out in the Strait of Sic…
Diuron mobility through vineyard soils contaminated with copper
2005
International audience; The herbicide diuron is frequently applied to vineyard soils in Burgundy, along with repeated treatments with Bordeaux mixture (a blend of copper sulfate and calcium hydroxide) that result in elevated copper concentrations. Cu could in principle affect the fate and transport of diuron or its metabolites in the soil either directly by complexation or indirectly by altering the populations or activity of microbes involved in their degradation. To assess the effect of high Cu concentrations on diuron transport, an experiment was designed with ten undisturbed columns of calcareous and acidic soils contaminated with 17–509 mg kg−1 total Cu (field-applied). Grass was plant…
Actual provision as an alternative criterion to improve the efficiency of payments for ecosystem services for C sequestration in semiarid vineyards
2016
The aim of this paper is to evaluate the efficiency of the PES scheme actually used in the Sicilian rural development program, based on an egalitarian criterion, and proposing an alternative scheme in order to guarantee a greater equity and fairness of premium distribution in relation to soil carbon (C) sequestration potential. We, first, assessed the ecosystem services (ES) provided by agri-environmental measures (AEM) in terms of SOC stock increase in Sicilian vineyards. Based on these data we evaluated the efficiency of agro-environmental payments according to an egalitarian criterion and simulated the effects of the actual provision criterion adoption. Results showed that the adoption o…
Challenges in the use of Near Infrared Spectroscopy for improving wood quality: A review
2018
Aims of study: Forestry-related companies require quality monitoring methods capable to pass a large number of samples. This review paper is dealing with the utilization of near infrared (NIR) technique for wood analysis.Area of study: We have a global point of view for NIR applications and characterization of different kind of wood species is considered.Material and methods: NIR spectroscopy is a fast, non-destructive technique, applicable to any biological material, demanding little or no sample preparation. NIR spectroscopy and multivariate analysis serve well in laboratories where the conditions are controlled. The main challenges to NIR spectroscopy technique in field conditions are mo…
Data from: Fishing pressure impacts the abundance gradient of European lobsters across the borders of a newly established marine protected area
2018
Marine protected areas (MPAs) are considered as viable fisheries management tools due to their potential benefits of adult spillover and recruitment subsidy to nearby fisheries. However, before-after-control-impact (BACI) studies that explore the biological and fishery effects of MPAs to surrounding fisheries are scarce. We present results from a fine-scale spatial gradient study conducted before and after the implementation of a 5km2 lobster MPA in southern Norway. A significant non-linear response in lobster abundance, estimated as catch-per-unit-effort (CPUE) from experimental fishing, was detected within two years of protection. After 4 years, CPUE values inside the MPA had increased by…
Effects of dietary dehydrated lemon peel on some biochemical markers related to general metabolism, welfare and stress in gilthead seabream (Sparus a…
2019
Dehydrated lemon peel (DLP) at two levels (1.5% and 3%) was included for 30 days in the diet of gilthead seabream (Sparus aurata L.) and after 15 and 30 days the serum and skin mucus of fish were analysed. In serum, both experimental diets led to an initial decrease in glucose and lactate after which the levels became comparable to the control. Dietary DLP modulated the activity of transaminases, alanine aminotransferase and aspartate aminotransferase. The total antioxidant status showed a progressive increase in relation to levels of inclusion of DLP and time of administration (p '.05). In skin mucus, some biomolecular markers related to general stress, oxidative stress and apoptosis exhib…
Isolation and confirmation of viral nervous necrosis (VNN) disease in golden grey mullet (Liza aurata) and leaping mullet (Liza saliens) in the Irani…
2016
The present study was conducted on 428 moribund mullet fish samples to isolate and identify the causative agent of a mysterious acute mortality which recently occurred in wild mullets in Iranian waters of Caspian Sea, suspected to be due to viral nervous necrosis (VNN) disease. Disease investigation was carried out employing various diagnostic procedures such as virology, bacteriology, parasitology, haematology, histopathology, IFAT, IHC and nested RT-PCR. Brain and eye samples of affected fishes were collected in sterile conditions and then kept at -80 °C for cell culture isolation and nested RT-PCR detection of the causative agent. Other tissue samples were also collected and fixed for hi…