57 resultados para Overview

em Aquatic Commons


Relevância:

20.00% 20.00%

Publicador:

Resumo:

(PDF contains 80 pages.)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Over the years, Nigeria have witnessed different government with different policy measures. Against the negative consequences of the past policies, the structural adjustment was initiated in 1986. Its aims is to effectively altar and restructure the consumption patterns of the economy as well as to eliminate price distortions and heavy dependence on the oil and the imports of consumer goods and services. Within the period of implementation, there has been a decreasing trend in yearly fish catch landings and sizes but the reverse in shrimping. There is also a gradual shift from fishing to shrimping, from the vessels purchased with 83.3% increase of shrimpers from 1985 to 1989. Decreasing fish catch sizes and quantity aggravated by the present high cost of fishing coupled with the favourable export market for Nigeria shrimp tend to influence the sift. This economic situation is the result of the supply measures of SAP through the devaluation of the Naira. There is also overconcentration of vessels on the inshore waters as majority of the vessels are old and low powers hence incapable of fishing on the deep sea. Rotterdam price being paid for automotive gas oil (AGO) by fishing industries is observed to be discriminating and unhealthy to the growth of the industry as it is exceedingly high and unstable thus affecting planning for fishing operation. Fuel alone takes 43% of the total cost of operation. The overall consequences is that fishing days are loss and therefore higher overhead cost. It was concluded that for a healthy growth and sustainable resources of our marine fishery under the structural adjustment programme licensing of new fishing vessels should be stopped immediately and the demand side of SAP should be employed by subsidizing high powered fishing vessels which can operate effectively on the deep sea

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Aspects of the Nigerian fishing industry are outlined to explain the concept of fishing systems viability which is often influenced by a combination of factors including biological productivity, as well as technical, economic and social factors. The productivity of the aquatic environments can be increased by the construction and installation of artificial reefs and fish aggregating devices. These man-made structures provide shelters, food and breeding grounds for fin fish and shell fish. The habitat enhancement techniques are appropriate, efficient, cheap and simple strategic options for increase in fish production. Recommendations for effective utilization and long term management are outlined.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fishing gears and methods that target the Clupeids are atalla lift net, light attraction, midwater trawl and dala (Clupeid beach seine).Dala fisheries have been the most lucrative fishing gear on Clupeids within the recent past. However, it has been declared as 100% illegal gear having a mesh size of 0.1 mm, because it catches indiscriminately undersized (juveniles/larvae) commercial fish. The ban on the gear was therefore mounted through promulgation and implementation of special fisheries laws for Kainji Lake (Nigeria). Although, the use of Dala fishing gear and method has decreased due to this management approach, its use is currently increased again. It is therefore suggested that the ban on the use of Dala may not be the answer to indiscriminate fisheries, but modification of the gear and methods for harvesting Clupeids should be the main objective

Relevância:

20.00% 20.00%

Publicador:

Resumo:

An overview is provided of the literature of socio-economic relevance to the fisheries of Lake Victoria. It covers the following areas: marketing studies; management; changes to the structure of the fishery; and, base-line studies. The bibliography provides a guide to the more important documents on Lake Victoria's socio-economy and includes a total of 177 references

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Small-scale fisheries is traditional and rural based. Therefore, the paper is an over view of small-scale fisheries resources management in Nigeria. It provides about 80-90% employment to surrounding population. The small-scale fisheries are grouped in to two major sectors:- the artisanal or capture fisheries and aquaculture farming. The paper identified some management problems such as:- multi uses of the water bodies, lack of or inadequate data upon which sound management strategies are based, ownership of inland water bodies is a problem, uncontrolled exploitation hampers sustainable development, poor and low technology and lack of capital, land and credit facilities. The paper presented some management options for sustainable management. Measures to reduced fish spoilage have been advanced. Also highlighted is the role of fish culture in small-scale fisheries management

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Macroeconomic growth and the development of sustainable business activities are interrelated. In Lagos State, aquaculture is a marginal economic activity thriving mainly on a semi-intensive level. Notwithstanding the available potentials for the development of successful commercial aquaculture enterprises in the state, the transformation to a full-flagged industry continues to be undetermined by certain critical factors. Feasible development strategies may be sought in increasing all stakeholders' capacity in the formulation of policies, plans and regulations, a complete separation of aquaculture from the capture fisheries in administrative structure and policy; the adoption of precautionary approach; provision of economic incentives to enhance private investments and increase output,respectively

Relevância:

20.00% 20.00%

Publicador:

Resumo:

An overview is provided of studies on hypertrophic phytoplankton in order to explore the subject and to suggest uncovered areas of research in this increasingly important theme. The authors restrict themselves to stagnant environments, using a community criterion to define hypertrophic environments. They are defined as those whose yearly average of phytoplankton chlorophyll is equal to or higher than 100 mg per cubic metre of water. The paper deals with species composition, diversity, biomass, primary production, losses and seasonal succession of hypertrophic phytoplankton. Other topics, such as population dynamics and ecophysiological issues, either lack enough information to be considered or are well known, e.g. Microcystis and Oscillatoria ecophysiology.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A number of diadromous gobies, notably Sicydium spp. and Sicyopterus spp., support fisheries based on return migrations of postlarvae (fry) to rivers. Most species are tropical, although close relatives occur in Japan. The life history of this group has often been incorrectly described as catadromous (spawning in the sea or estuary), whereas anadromous (spawning in rivers) would be more accurate.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

While Africa’s inland fisheries are widely recognized to be of great importance to local people, accurate and up-to-date information on their value is sparse and its absence is a serious constraint to the formulation of effective fisheries policies and management practices. As a contribution to current efforts to address this constraint, this paper reviews the different methods that are potentially applicable to the valuation of inland fisheries and discusses their respective rationales and limitations within a multi-sectoral, multi-user context. The livelihood analysis approach is given special emphasis. The complementarity of this recently developed approach with the other, more conventional, environmental economics methods is illustrated.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fisheries conflicts are among the persistent problems affecting the security of food, livelihoods and fishing environments crucial to poor fishing communities in developing countries in South and Southeast Asia. Most conflicts arise from excessive fishing efforts due to increasing population and economic motivations. Conflicts are not all undesirable as some disputes become a catalyst for much needed reforms for policy and economic improvements. However, a framework for analyzing conflicts in fisheries is necessary to organize interventions relevant to the nature of conflicts, and the needs and capacities of fisheries stakeholders in the region. The WorldFish Center, together with research partners, conducted studies that identify a framework for managing fisheries conflicts. Thematic policy recommendations for managing fishing capacity and related conflicts in small-scale fisheries in the region are identified for further consideration by fisheries stakeholders.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The U.S. Atlantic coast and Gulf of Mexico commercial shark fisheries have greatly expanded over the last 30 years, yet fishery managers still lack much of the key information required to accurately assess many shark stocks. Fishery observer programs are one tool that can be utilized to acquire this information. The Commercial Shark Fishery Observer Program monitors the U.S. Atlantic coast and Gulf of Mexico commercial bottom longline (BLL) large coastal shark fishery. Data gathered by observers were summarized for the 10-year period, 1994 to 2003. A total of 1,165 BLL sets were observed aboard 96 vessels, with observers spending a total of 1,509 days at sea. Observers recorded data regarding the fishing gear and methods used, species composition, disposition of the catch, mortality rates, catch per unit of effort (sharks per 10,000 hook hours), and bycatch of this fishery. Fishing practices, species composition, and bycatch varied between regions, while catch rates, mortality rates, and catch disposition varied greatly between species.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Of the five populations of beluga, Delphinapterus leucas, in Alaska, the most isolated is the one in Cook Inlet (Hazard, 1988; Hill and DeMaster, 1998) (Fig. 1). The geographic and genetic segregation of this stock (O’Corry-Crowe et al., 1997), combined with the beluga’s tendency toward site fidelity in summer, makes this population especially vulnerable to impacts from large or persistent harvests.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Prawn trawling occurs in most states of Australia in tropical, subtropical, and temperate waters. Bycatch occurs to some degree in all Australian trawl fisheries, and there is pressure to reduce the levels of trawl fishery bycatch. This paper gives a brief overview of the bycatch issues and technological solutions that have been evaluated or adopted in Australian prawn-trawl fi sheries. Turtle excluder devices (TED’s) and bycatch reduction devices (BRD’s) are the principal solutions to bycatch in Australian prawn-trawl fisheries. This paper focuses on a major prawn-trawl fishery of northeastern Australia, and the results of commercial use of TED’s and BRD’s in the Queensland east coast trawl fishery are presented. New industry designs are described, and the status of TED and BRD adoption and regulation is summarized. The implementation of technological solutions to reduce fishery bycatch is assumed generally to assist prawn-trawl fisheries within Australia in achieving legislative requirements for minimal environmental impact and ecological sustainable development.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Guam's nearshore reef fishery is a multi-gear, multispecies fishery that has undergone major changes through the years. Methods have evolved and become more modern. This, along with the changing economic status of Guam, has severely stressed the fishery. Top targeted species are being overexploited and "growth overharvesting" is occurring; the more serious form of "recruitment overharvesting," is happening to some of the key species. Major management concerns are discussed with respect to overfishing and habitat destruction. Management recommendations for this fishery include gear restrictions, size restrictions, and the establishment of marine conservation areas.