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21.
The main results of research work carried out since 1998 with regard to the application of hydro-acoustic technologies for the evaluation of biomass and distribution of small pelagic fish species off the southern coast of Sicily are presented, taking into account information from hydrology and from ecology of the fish populations targeted. The biomass estimates and the population‐density charts presented concern the two main species, i.e. sardine Sardina pilchardus (Walbaum, 1792) and anchovy Engraulis encrasicolus (Linnaeus, 1758). Both the sardine and anchovy populations experienced large inter-annual fluctuations, with biomass estimates ranging from 6000 to over 36,000 tonnes (t) (sardine) and from about 7000 to 23,000 t (anchovy). Acoustic estimates are largely consistent with landings recorded in Sciacca (the main fishing port for small pelagic species in the study area) during the year following the evaluation surveys. In addition, trends in sardine and anchovy biomass estimates appears to be negatively correlated with the mean sea surface temperature calculated over the time intervals January–September (sardine) and June–November (anchovy) of the preceding year, which correspond to larval and juvenile growth periods of target species. Observed patterns would suggest the importance of enrichment processes relevant to the survival of early stages, so determining recruitment success and finally higher population sizes.  相似文献   
22.
Disposal of sewage sludge in the New York Bight Apex (12-Mile Dump Site) ceased at the end of December 1987. Previous efforts to quantify the effects of sludge were hindered by the inability to obtain true replication. the cessation of dumping afforded the opportunity to apply the technique of replication in time, also known as a Before/After, Control/Impact design. Conditionally, this method allows one to separate treatment effects from the natural differences that confound many environmental impact studies. the Environmental Processes Division of the Northeast Fisheries Center, National Marine Fisheries Service sampled the benthic environment of the New York Bight Apex from June 1986 through September 1989 using a sample design based on the technique of replication in time.

Three dominant species (rock crab, Cancer irroratus; little skate; Raja erinacea; and winter flounder, Pseudopleuronectes americanus) and total demersal finfish, collected by otter trawl, showed no statistically significant response to the cessation of disposal. American lobster (Homarus americanus) increased in local abundance, but this result was possibly confounded by a change in fishing effort.  相似文献   
23.
Polychlorinated-dibenzo-p-dioxins (PCDDs), -dibenzofurans (PCDFs) and -dioxin-like polychlorinated biphenyls (DLPCBs) were determined in aquatic wildlife of Kasumigaura Lake (KUL), Japan from 1978 to 2001. Two plankton species elucidated several fold greater concentrations (2400–7800) than small tiger fish (310–6500), shrimp (160–1100), and three large fish namely, black bass (120–240), carp (94–120) and mullet (54) on pg/g fat. PCDD homologues were predominant accumulants with >68–<95% contribution and remaining was shared by PCDFs. Accumulation, non-ortho DLPCBs in plankton (3500–9200), shrimp (1600–8600) and small fish (2000–8800) and large fish (1300–3900) on ng/g fat basis were several orders magnitude greater than PCDD/DFs. The mono-ortho DLPCBs in large fish species were 23?000–83?000?ng/g fat and which it is accounted 94.3–95.9% the total dioxin-like PCBs accumulation. Temporal trends of PCDDs, PCDFs, non-ortho PCBs and TEQ in shrimp and small tiger fish were varied. The mullet had minimum toxic equivalency “TEQ” (14?pg?TEQ/g) followed by plankton Neomysis intermedia (25?pg?TEQ/g), small tiger fish (mean: 33, ranges 14–66?pg?TEQ/g), plankton Cyclopus vicinus (34?pg?TEQ/g), carp (mean: 35, ranges 32–38?pg?TEQ/g), shrimp (mean: 38, ranges 11–68?pg?TEQ/g) and black bass (mean: 59, ranges 38–79?pg?TEQ/g) on fat basis. In all the samples, PCDD was predominant TEQ contributor followed by PCDFs and DLPCBs. The contribution of mono-ortho DLPCBs to the total TEQ was 0.52–0.92 in large fish.  相似文献   
24.
This paper assesses quantitatively the impact of sea level rise (SLR) at the global and regional scale as a result of climate change (CC) on the coastal areas of the Kingdom of Bahrain’s islands (36 Islands). The standard Intergovernmental Panel on Climate Change (IPCC) guidelines was modified as appropriate for the situation of the study area. Geographic Information Systems (GIS) coupled with Remote Sensing (RS) were used as the main techniques of collecting, analyzing, modeling simulating and disseminating information to build SLR scenarios in a geographically referenced context. Also, these tools were used to assess vulnerability and risk of the coastal area of the islands with the expectation that coastal planner and government authorities will profit from integrating these knowledge into a broad based environmental decision making. Three SLR scenarios: low, moderate and high were developed to examine the impacts from SLR on all islands. The low SLR scenario (Optimistic) assumes a 0.5-m rise above current sea level, the moderate scenario (Intermediate) assumes a one meter rise, and the high scenario (Pessimistic) assumes a 1.5 m rise in sea level. Two more SLR scenarios were assumed to perform risk analysis, a 2 and 5 meter rise above current sea level. The simulation of SLR are quite straightforward, emphasizing on the uses of both of the data that are incorporated from the satellite images and the created Digital Elevation Model (DEM) to estimate SLR scenarios that are adapted in the study. These data were used to predict consequences of the possibility of the rise in sea level at different scenarios which may alter the landuse and patterns of human communities. Results indicate that low-lying coastal areas of Bahrain islands are at risk from the effects of any SLR resulting from CC. These islands are vulnerable under different SLR Scenarios. More than 17% of the country total area may be inundated under 1.5 m SLR in 2100. The total area that might be lost under different sea level scenarios will vary from more than 77 km2 if SLR reaches 0.5 m, to about 100 km2 under 1.0 m SLR and may reach 124 km2 under 1.5 m SLR scenario. The total inundated areas due to risk scenarios will reach 133 km2, if the SLR rises to 2.0 m, and it is estimated to be more than (22%) of the main island total area. Under the second scenario, if the SLR reaches 5.0 m, the main islands will lose approximately half of its area (47%) equal to 280 km2. Hawar islands group will lose about (30%) of its total area under 2.0 m SLR, which is about 15.5 km2.A SLR adaptation policy framework (APF) and adaptation policy initiatives (APIs) are suggested for planners to build upon for reducing the likely effects of SLR in the Kingdom of Bahrain. The framework is composed of four steps namely, acquisition of information, planning and design, implementation and monitoring and evaluation. A general policy framework for a national response to SLR is suggested. Additionally, a range of policy adaptation options/initiatives to sustain coastal developments under the likely effects of SLR are recommended.  相似文献   
25.
Introduction: A 2-year prospective study evaluated the effectiveness of a managerial training program to enhance corporate compliance with statewide worksite safety and health regulations. The program offered participants information about regulatory requirements and emphasized organizational and environmental strategies for reducing occupational injuries and illnesses. Objectives: To assess the effects of a train-the-trainer program on business managers' knowledge of statewide occupational safety and health legislation and on levels of corporate compliance with regulatory requirements. Methods: Forty-eight small- and medium-sized companies participated in the training sessions during the first year of the study. These firms were compared with 46 control companies that did not receive the training until the conclusion of the study. Results: Participation in the program was associated with higher levels of corporate regulatory compliance 12 months after the training sessions were held (controlling for baseline levels of corporate compliance with the regulations). Program effects on compliance levels were mediated by posttraining changes in managers' knowledge of regulatory requirements. Conclusions: The REACH OUT training program raised managers' awareness of and corporate compliance with statewide worksite safety and health regulations. Impact on Industry: Smaller companies face greater challenges than larger ones in developing and maintaining worksite safety and health programs. Barriers to regulatory compliance, especially in small- and medium-size companies, should be identified and removed to enhance the efficacy of these programs.  相似文献   
26.
The Lagoon Olho d'Água in Pernambuco State, Northeast Brazil has received increasing environmental concern due to significant stress from pollution in the catchment. The existing environmental problems are the result of great pressure from a broad range of human activities, especially in the last 10 years. Serious pollution exists mainly from some industrial and urban activities, which increased intensively after the eighties. There is a strong social and economical pressure for housing and construction near the lagoon, due to the available land nearby beaches and estuarine zone, and recently by growing tourism activities. Uncontrolled land use by low-income communities and the pressure for construction by developers have led to landfilling and to deterioration of water quality in the lagoon catchment. Improvement of the environmental conditions in the catchment needs integrated measures. Guidelines and some specific actions involving several institutions have been established and refer to sanitation and urban infrastructure as the main priorities. A main target is the construction of low-cost sewage system with smaller and decentralised treatment plants.  相似文献   
27.
生态农业发展与小城镇建设   总被引:4,自引:0,他引:4  
以3家生态村为例说明乡镇企业在生态农业产值中占据主导地位。通过对乡镇企业的经济效益、环境效益和社会效益以及小城镇发展的优越性分析可知,乡镇企业不宜在农村发展,应该在小城镇中发展,农村生态建设要立足农业,通过减少土地的人口承载量,提高劳动生产率和增加农民收入。  相似文献   
28.
20世纪后半叶,三江平原进行了大规模的开发,虽然为国家粮食供应做出了贡献,但大片湿地遭到破坏。现在为拯救中国这块唯一保持原始面貌的淡水湿地,当地政府制定了具体的三江平原湿地保护条例。建立了国家级的自然保护区,保护三江平原湿地终于纳入了政府工作的议事日程,为了加深人们对保护三江平原湿地意义的认识,本文从分析三江平原湿地的自然状况、三江湿地开发对当地生态和经济的影响入手,论述了三江平原湿地保护的重要意义和应采取的具体措施。  相似文献   
29.
Introduction: This study addressed relative injury risk among Norwegian farmers, who are mostly self-employed and run small farm enterprises. The aim was to explore the relative importance of individual, enterprise, and work environment risks for occupational injury and to discuss the latent conditions for injuries using sociotechnical system theory. Method: Injury report and risk factors were collected through a survey among Norwegian farm owners in November 2012. The response rate was 40% (n = 2,967). Annual work hours were used to calculate injury rates within groups. Poisson regression using the log of hours worked as the offset variable allowed for the modeling of adjusted rate ratios for variables predictive of injury risk. Finally, safety climate measures were introduced to assess potential moderating effects on risk. Results: Results showed that the most important risk factors for injuries were the design of the workplace, type of production, and off-farm work hours. The main results remained unchanged when adding safety climate measures, but the measures moderated the injury risk for categories of predominant production and increased the risk for farmers working with family members and/or employees. An overall finding is how the risk factors were interrelated. Conclusions: The study identified large structural diversities within and between groups of farmers. The study drew attention to operating conditions rather than individual characteristics. The farmer’s role (managerial responsibility) versus regulation and safety climate is important for discussions of injury risk. Practical Applications: We need to study sub-groups to understand how regulation and structural changes affect work conditions and management within different work systems, conditioned by production. It is important to encourage actors in the political-economic system to become involved in issues that were found to affect the safety of farmers.  相似文献   
30.
In order to develop small islands, not only must a vital agricultural system be maintained, but the range of opportunities for tourism must be increased with respect to both the seaside and the environmental features of the rural landscape. As an alternative to the traditional and economically declining ones, many innovative production processes can be identified, but their success depends on their interaction with the physical, biological, economic and social environment. In order to identify the main nodes and the most critical interactions, so as to increase the probability of success of a new productive process, a methodological approach based on the science of complexity is proposed for the cultivation of capers (Capparis spinosa L.) on the island of Pantelleria. The methodology encompasses the identification of actors and factors involved. the quantitative evaluation of their interactions with the different stages of the productive process, and a quasiquantitative evaluation of the probability that the particular action will be performed successfully. The study of “traditional,” “modernized,” and “modernized-sustainable” processes, shows that the modernized-sustainable process offers mutually reinforcing opportunities in terms of an integrated development of high-quality agricultural products and the enhancement of environmental features, in conjunction with high-efficiency production techniques, in conjunction with high-efficiency production techniques, in a way that suits the development of Pantelleria. There is a high probability of failure, however, as a result of the large number of critical factors. Nevertheless, the present study indicates which activities will enhance the probability of successful innovation in the production process.  相似文献   
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