48 resultados para Progettazione dinastica, Marpatech s.r.l., riorganizzazione, sistemi produttivi
em Aquatic Commons
Resumo:
Secondary metabolites are produced by aquatic plants, and in some instances, exudation of these metabolites into the surrounding water has been detected. To determine whether infestations of Eurasian watermilfoil or hydrilla produce such exudates, plant tissues and water samples were collected from laboratory cultures and pond populations and were analyzed using solid phase extraction, HPLC, and various methods of mass spectrometry including electrospray ionization, GC/MS, electron impact and chemical ionization. Previously reported compounds such as tellimagrandin II (from Eurasian watermilfoil) and a caffeic acid ester (from hvdrilla), along with a newly discovered flavonoid, cyanidin 3 dimalonyl glucoside (from hydrilla), were readily detected in plant tissues used in this research but were not detected in any of the water samples. If compounds are being released, as suggested by researchers using axenic cultures, we hypothesize that they may be rapidly degraded by bacteria and therefore undetectable.
Resumo:
EXECUTIVE SUMMARY: The Coastal Change Analysis Programl (C-CAP) is developing a nationally standardized database on landcover and habitat change in the coastal regions of the United States. C-CAP is part of the Estuarine Habitat Program (EHP) of NOAA's Coastal Ocean Program (COP). C-CAP inventories coastal submersed habitats, wetland habitats, and adjacent uplands and monitors changes in these habitats on a one- to five-year cycle. This type of information and frequency of detection are required to improve scientific understanding of the linkages of coastal and submersed wetland habitats with adjacent uplands and with the distribution, abundance, and health of living marine resources. The monitoring cycle will vary according to the rate and magnitude of change in each geographic region. Satellite imagery (primarily Landsat Thematic Mapper), aerial photography, and field data are interpreted, classified, analyzed, and integrated with other digital data in a geographic information system (GIS). The resulting landcover change databases are disseminated in digital form for use by anyone wishing to conduct geographic analysis in the completed regions. C-CAP spatial information on coastal change will be input to EHP conceptual and predictive models to support coastal resource policy planning and analysis. CCAP products will include 1) spatially registered digital databases and images, 2) tabular summaries by state, county, and hydrologic unit, and 3) documentation. Aggregations to larger areas (representing habitats, wildlife refuges, or management districts) will be provided on a case-by-case basis. Ongoing C-CAP research will continue to explore techniques for remote determination of biomass, productivity, and functional status of wetlands and will evaluate new technologies (e.g. remote sensor systems, global positioning systems, image processing algorithms) as they become available. Selected hardcopy land-cover change maps will be produced at local (1:24,000) to regional scales (1:500,000) for distribution. Digital land-cover change data will be provided to users for the cost of reproduction. Much of the guidance contained in this document was developed through a series of professional workshops and interagency meetings that focused on a) coastal wetlands and uplands; b) coastal submersed habitat including aquatic beds; c) user needs; d) regional issues; e) classification schemes; f) change detection techniques; and g) data quality. Invited participants included technical and regional experts and representatives of key State and Federal organizations. Coastal habitat managers and researchers were given an opportunity for review and comment. This document summarizes C-CAP protocols and procedures that are to be used by scientists throughout the United States to develop consistent and reliable coastal change information for input to the C-CAP nationwide database. It also provides useful guidelines for contributors working on related projects. It is considered a working document subject to periodic review and revision.(PDF file contains 104 pages.)
Resumo:
Estimates of dolphin school sizes made by observers and crew members aboard tuna seiners or by observers on ship or aerial surveys are important components of population estimates of dolphins which are involved in the yellowfin tuna fishery in the eastern Pacific. Differences in past estimates made from tuna seiners and research ships and aircraft have been noted by Brazier (1978). To compare various methods of estimating dolphin school sizes a research cruise was undertaken with the following major objectives: 1) compare estimates made by observers aboard a tuna seiner and in the ship's helicopter, from aerial photographs, and from counts made at the backdown channel, 2) compare estimates of observers who are told the count of the school size after making their estimate to the observer who is not aware of the count to determine if observers can learn to estimate more accurately, and 3) obtain movie and still photographs of dolphin schools of known size at various stages of chase, capture and release to be used for observer training. The secondary objectives of the cruise were to: 1) obtain life history specimens and data from any dolphins that were killed incidental to purse seining. These specimens and data were to be analyzed by the U.S. National Marine Fisheries Service ( NMFS ) , 2) record evasion tactics of dolphin schools by observing them from the helicopter while the seiner approached the school, 3) examine alternative methods for estimating the distance and bearing of schools where they were first sighted, 4) collect the Commission's standard cetacean sighting, set log and daily activity data and expendable bathythermograph data. (PDF contains 31 pages.)
Resumo:
The study was carried to examine the contribution of women to fisheries development in the Kainji basin. The sample was drawn in some of the major fishing villages in the sub strata of the basin. A total of 120 respondents were used. The findings revealed that women were involved in fisheries activities most especially in the processing and marketing aspects. Many of the respondents happened to be wives of the fishermen. Few bought fishing equipment with a special arrangement for the supply of fish while some buy from fishermen. This revealed the willingness of the women to be empowered in the economic activities in the area to meet some basic household. Major constrains to the women in this area were the scarcity of fish, no support from the government or private agencies. Recommendations were made on how to enhance women participation in fisheries development
Resumo:
The quest for food security and poverty alleviation among rural fisherfolks is imperative in the context of rural development. Rural fishermen and women do not only partake in fishing and related activities in order to make ends meet but also seek more sustainable ways of absorbing shocks and reducing their vulnerability to unforeseen economics conditions. These they do through diversification of their efforts to such activities that enables them have good leverage over poverty and food scarcity. It is in this context that Nigerian-German Technical Co-operation (GTZ) sought to assist the fisherfolks to help themselves by training the fishermen wives on knowledge and skill acquisition in Soya bean processing and utilization as a means of generating additional income for the household in Kainji Lake basin. This work was therefore carried out in order to make an objective investigation into the impact of this training on the economy of the fisherfolks. Sixty respondents, who constitute fishermen wives, were randomly selected from twelve fishing villages in the basin. 76.7% of those interviewed affirmed that the project has increased their income while others agreed that it has actually reduced their expenditure on food while increasing food supply and variety for the household
Resumo:
Artisanal fisheries development in Nigeria, like in any other developing country of the world is characterized by subsistence level of operation using dugout canoe and paddle. This implies that parents and children constituted the labour in use since they only struggle for the upkeep of the family. A total of 240 questionnaires were used to solicit information from the respondents. This total was divided into 120 each for both parents and the youths respectively. Simple descriptive statistics such as frequency distribution and percentages were used to analyze their responses. Parents have strong aspiration for their children to succeed them hence, 78.3% of the parents expressed their aspiration for succession by the younger ones while 83.3% of parents tend to support their aspiration with persuasive strategies such as allowing their children to partake in fishing activities at will. On the part of the youth over 70% of them perceived fishing as a viable business where they can succeed their parents provided government can come to their aid in form of active involvement in the development of rural fisheries. It is therefore believed that fisheries development could achieve rapid improvement if the aspiration of the parents is balanced with perception of the youth and the government meets their expectation
Effects of suspended sediments on the development of eggs and larvae of striped bass and white perch
Resumo:
The possible ecological effects of suspended sediments are manifold. Briefly, suspended sediments may cause an increased surface for microorganism growth, fewer temperature fluctuations, chemical adsorption or absorption, blanketing, mechanical-abrasive actions, and light penetration reduction (Cairns, 1968). Sherk and Cronin (1970) have pointed out that the above effects have been little studied in the estuarine environment. The ecological effects of suspended sediments on fish eggs and larvae may be of prime importance t o the C and D Canal area, an important spawning and primary nursery area for a variety of estuary: e species (Johnson,1972). This section discusses the effects of suspended sediment on the eggs and larvae of striped bass and white perch.
Resumo:
River fisheries in Africa are important because of their contribution of animal protein to human diets. Such fisheries are highly dependent on hydrological regimes and show considerable year-to-year variation in response to natural climatic events. River flow regimes are being increasingly altered by withdrawals by man, principally for agriculture. The modification of hydrological regimes is leading to diminishing catches of fish and changes in the number and size of the species caught. Given that the trend to remove water from rivers for agriculture and power generation will continue, better appraisals of the impacts of such withdrawals are urgently needed so the policies for water allocation can be better defined. The development of tools to aid in such decision-making is equally important.
Resumo:
Background: The rising temperature of the world’s oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin. Methodology/Principal Findings: Satellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers’ field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior efforts in detail and extent, and provided a new standard for documenting the effects of bleaching and for testing nowcast and forecast products. Collaborators from 22 countries undertook the most comprehensive documentation of basin-scale bleaching to date and found that over 80% of corals bleached and over 40% died at many sites. The most severe bleaching coincided with waters nearest a western Atlantic warm pool that was centered off the northern end of the Lesser Antilles. Conclusions/Significance: Thermal stress during the 2005 event exceeded any observed from the Caribbean in the prior 20 years, and regionally-averaged temperatures were the warmest in over 150 years. Comparison of satellite data against field surveys demonstrated a significant predictive relationship between accumulated heat stress (measured using NOAA Coral Reef Watch’s Degree Heating Weeks) and bleaching intensity. This severe, widespread bleaching and mortality will undoubtedly have long-term consequences for reef ecosystems and suggests a troubled future for tropical marine ecosystems under a warming climate