Search results for "Fishe"
showing 10 items of 2001 documents
Dispersal of larval and juvenile seabream: Implications for Mediterranean marine protected areas
2015
International audience; In the marine context, information about dispersal is essential for the design of networks of marine protected areas (MPAs). Generally, most of the dispersal of demersal fishes is thought to be driven by the transport of eggs and larvae in currents, with the potential contribution of dispersal in later life stages relatively minimal.Using otolith chemistry analyses, we estimate dispersal patterns across a spatial scale of approximately 180 km at both propagule (i.e. eggs and larvae) and juvenile (i.e. between settlement and recruitment) stages of a Mediterranean coastal fishery species, the two-banded seabream Diplodus vulgaris. We detected three major natal sources …
Nested assemblages resulting from host size variation: the case of endoparasite communities in fish hosts
2001
Nested species subsets are a common pattern in many types of communities found in insular or fragmented habitats. Nestedness occurs in some communities of ectoparasites of fish, as does the exact opposite departure from random assembly, anti-nestedness. Here, we looked for nested and anti-nested patterns in the species composition of communities of internal parasites of 23 fish populations from two localities in Finland. We also compared various community parameters of nested and anti-nested assemblages of parasites, and determined whether nestedness may result simply from a size-related accumulation of parasite species by feeding fish hosts. Nested parasite communities were characterised b…
Do small marinas drive habitat specific impacts? A case study from Mediterranean Sea.
2011
Many human activities add new structures to the marine landscape. Despite the fact that human structures cause some inevitable impacts, surprisingly little information exists on the effects of marina on natural marine assemblages. The aim of this paper is to assess habitat-specific response of benthic sessile organisms of rocky shores in relation to the presence of a small marina. Sampling was carried out at three coastal habitats (midshore, lowshore and subtidal) by means of visual censuses adopting an after-control-impact (ACI) experimental design. It appears that the marina affects the structure and composition of benthic communities of both the midshore and the lowshore. Little effect w…
Deep-sea shrimp fishery in Sicily: The economic performance of the shrimp trawling fleet in the ports of Mazara del Vallo, Sciacca, and Porto Empedoc…
2006
Shrimp fishing in Sicily is carried out by fishing companies using trawlers and multifunctional vessels equipped with trawling nets, in a complex and worrisome context, because of the decrease in catch over the last few years. After analysing the structural characteristics of Sicilian trawling, the study concentrates on the three most important shrimp fishing ports in Sicily: Mazara del Vallo, Sciacca, and Porto Empedocle. For each fleet, through a sample analysis, economic performance has been evaluated for the period from 2001 to 2003. Finally, a comparative analysis of the economic performance of the surveyed companies is carried out through a comparison of daily economic productivity in…
Effects of fish feeding by snorkellers on the density and size distribution of fishes in a Mediterranean marine protected area
2005
Although there is a great deal of evidence to show that supplementary feeding by humans in terrestrial environments causes pronounced changes in the distribution and behaviour of wild animals, at present very little is known about the potential for such effects on marine fish. This study evaluated the consequences of feeding by snorkellers on fish assemblages in the no-take area of the Ustica Island marine protected area (MPA; western Mediterranean) by (1) determining if reef fish assemblage structure is affected in space and time by tourists feeding the fish; (2) assessing the effects of feeding on the abundance of the most common fish species; and (3) assessing the effects of feeding on t…
Feeding habits of the spotted flounder Citharus linguatula off the eastern coast of Spain
1994
The composition of the diet of Citharus linguatula (L.) off the coast of the Gulf of Valencia, Spain, was determined between October 1989 and October 1990. The percentage of empty stomachs remained constant throughout the year, except for the period August to September, when a maximum was recorded coinciding with the reproductive period. Crustaceans (Mysidacea and Decapoda) and teleosts constituted the main prey. The composition of the prey ingested varied with predator size; small specimens contained a greater number of mysids in their stomachs, while decapods and fishes were more abundant in the stomachs of larger specimens. Diets varied seasonally: mysids were more important during autum…
Recreational fish feeding affects coastal fish behavior and increases frequency of predation on damselfish (Chromis chromis) nests
2006
Wildlife feeding has become an integral part of the range of activities offered to protected area visitors. In marine protected areas (MPAs), fish feeding may cause changes in the behavior, and thus the density and distribution, of coastal fish species. We evaluated spatial variability in human-positive fish behavior around the Ustica Island MPA (Italy) and the potential indirect effects of behavioral change on other species. Two mensurative experiments demonstrated that ca. 1/3 of the species present in fish-feeding areas exhibited human-positive behavior, losing instinctive fear in the presence of humans and encircling people in the water even when food was not provided. A manipulative ex…
The Developmental Contribution From Mobile Phones Across the Agricultural Value Chain in Rural Africa
2011
Published version of an article from the journal: The Electronic Journal of Information Systems in Developing Countries. Also available fro the publisher: http://www.ejisdc.org/Ojs2/index.php/ejisdc/article/viewFile/849/377 The most widespread information and communication technology (ICT) in developing countries today is the mobile phone. The majority of people in the least developed countries still live in rural areas and their livelihood depends on the primary industries. This study investigates the use of mobile phones among farmers in rural Tanzania in order to supply empirical data on the developmental role of this technology. The results show that the improved access to communication…
Speculation and lottery-like demand in cryptocurrency markets
2021
Abstract This is the first paper that explores lottery-like demand in cryptocurrency markets. Since recent research provides evidence that cryptocurrency returns appear to be short-memory processes, we modify Bali, Cakici and Whitelaw’s (2011) and Bali, Brown, Murray, and Tang’s (2017) MAX measure and employ a weekly forecast horizon and daily log-returns from the previous week to calculate the metric for our portfolio sorts. From an econometric point of view, this study proposes statistical tests that are robust to unknown dynamic dependency structures in the cryptocurrency data. Our results show that average raw and risk-adjusted return differences between cryptocurrencies in the lowest a…
Motivations, adoption and impact of voluntary environmental certification in the Italian Forest based industry: The case of the FSC standard
2017
Abstract Over the past few years several private voluntary schemes have been developed worldwide to address the environmental issues in the forest based industry. Using survey data, this study analyse the main factors motivating companies operating in the Italian forest based industry to implement FSC (Forest Stewardship Council) standard, as a tool to promote responsible forest management and traceability of derived products, and the impact of this standard on the economic and organisational results. The findings provide evidences that signalling mechanisms drive the entrepreneurs towards the adoption of FSC certification, followed by moral and ethical reasons. In terms of impact, emerges …