Search results for "Fish"
showing 10 items of 3164 documents
Illegal fishing in Isla del Coco National Park: Spatial-temporal distribution and the economic trade-offs
2020
Abstract The Isla del Coco National Park, located on the Pacific coast of Costa Rica, is rich in biodiversity and has a high concentration of pelagic species. This high marine biodiversity makes the Isla del Coco National Park (PNIC) a very attractive place for illegal fishers. We analyzed a dataset covering 8 years (2003–2010) of patrol records from PNIC with the aim of determining, a) the spatial-temporal distribution of illegal fishing, b) other areas that could be prone to illegal fishing but are currently undetected, c) the most profitable areas for this activity and d) the economic trade-offs of this illegal activity in relation to potential gains and the costs. Residuals Autocovariat…
Predictive habitat suitability models to aid the conservation of elasmobranchs in Isla del Coco National Park (Costa Rica)
2021
Abstract Worldwide there is increasing concern for elasmobranch species given that their biological and ecological characteristics make them highly vulnerable to fishing pressure. The disappearance of these species could affect the structure and function of marine ecosystems, which would induce changes in trophic interactions at the community level. For effective conservation and management of elasmobranchs detailed knowledge of their habitat preferences is essential. Yet, there is a poor understanding of their spatial ecology. Isla del Coco National Park is an oceanic island in Pacific Costa Rica and renowned for being a sanctuary for migratory pelagic species, such as elasmobranchs and ot…
Economic comparison between offshore and inshore aquaculture production systems of European sea bass in Italy
2014
Abstract Offshore production system is predicted to increase in the near future driven by the lack of coastal space and lower environmental impacts. The aim of this paper has been to evaluate the economic performance of offshore production system respect to inshore one, by comparing net present value (NPV), discounted payback time (DPBT) and internal rate of return (IRR) of two Italian mariculture farms that produce European sea bass. Results showed a better economic profitability of offshore farm, even if sensitivity analysis revealed that financial indicators of both aquaculture production systems have been very sensitive to market condition changes. So, offshore production system could r…
A Note on Economic Impact of EFF on Sicilian Firms Performance
2018
Measure 2.3 of the European Fisheries Fund, in Sicily, claimed investments of fish firms in production capacity expansion and modernization of fish processing. Have these investments been effective in supporting the competitiveness of these firms and have they influenced the economic sustainability of the regional seafood chain? Proposed counterfactual analysis contributes to this assessment through a comparison of the business performance of funded and non-funded firms.
The isopotency of generally homologous parts of the body. Investigations upon the homeosis phenomena in the crayfish
1927
Izvilkums no: Wilhelm Roux' Archiv für Entwicklungsmechanik der Organismen, 109. Bd., 5. Heft, 1927.
Monetary Policy and the Exchange Rate During the Asian Crisis: Identification Through Heteroscedasticity
2003
This paper examines whether a monetary policy tightening (i.e., an increase in the domestic interest rate) was successful in defending the exchange rate from speculative pressures during the Asian financial crisis. We estimate a bivariate VECM for four Asian countries, and improve upon existing studies in two important ways. First, by using a long data span we are able to compare the effects of an interest rate rise on the nominal exchange rate during tranquil and turbulent periods. Second, we take into account the endogeneity of interest rates and identify the system by exploiting the heteroscedasticity properties of the relevant time series, following Rigobon (2002). We find that while ti…
No-till durum wheat yield success probability in semi arid climate: A methodological framework
2018
Abstract The aim of this study is to develop a framework for the evaluation of no-till (NT) yield success probability as a decision tool for farmers or decision makers. The effect of soil management on durum wheat yield has been tested on many long-term field experiments. Results of these researches were collected in a unique dataset to evaluate the success of NT management in comparison to conventional tillage (CT) as influenced by the aridity index, crop residue management and cropping system. A total of 519 observations of long-term experiments (>3years) regarding durum wheat in a number of areas with semi arid climate were included in the present study. The relative ratio of yield under…
Direct seeding mulch-based cropping increases both the activity and the abundance of denitrifier communities in a tropical soil
2009
International audience; This study evaluated the impact of direct seeding mulch-based cropping (DMC), as an alternative to conventional tilling (CT), on a functional community involved in N cycling and emission of greenhouse gas nitrous oxide (N2O). The study was carried out for annual soybean/rice crop rotation in the Highlands of Madagascar. The differences between the two soil management strategies (direct seeding with mulched crop residues versus tillage without incorporation of crop residues) were studied along a fertilization gradient (no fertilizer, organic fertilizer, organic plus mineral fertilizers). The activity and size of the denitrifier community were determined by denitrifica…
Application of multivariate analysis techniques for selecting soil physical quality indicators: A case study in long-term field experiments in Apulia…
2019
Long-term field experiments and multivariate analysis techniques represent research tools that may improve our knowledge on soil physical quality (SPQ) assessment. These techniques allow us to measure relatively stable soil conditions and to improve soil quality judgment, thereby reducing uncertainties. A monitoring of SPQ under long-term experiments, aimed at comparing crop residue management strategies (burning vs. incorporation of straw, FE1) and soil management (minimum tillage vs. no tillage, FE2), was established during the crop growing season of durum wheat. The relationships between five SPQ indicators (bulk density [BD], macroporosity [PMAC], air capacity [AC], plant available wate…
Performance of a Pilot-Scale Constructed Wetland and Medium-Term Effects of Treated Wastewater Irrigation of Arundo donax L. on Soil and Plant Parame…
2021
On marginal lands in the Mediterranean basin, giant reed (Arundo donax L.) represents one of the most interesting perennial crops due to high levels of biomass production. Considering periodic water shortage during the summer months in this area, the reuse of treated wastewater (TWW) would seem to be a good opportunity for the growth of the species. The aim of this study was to assess the medium-term effects of irrigation using freshwater (FW) and TWW on soil characteristics and growth in giant reed plants. TWW was obtained from a pilot-scale horizontal subsurface flow constructed wetland system (HSSF CWs) with a total surface area of 100 m2. A split-plot design for a two-factor experiment …