991 resultados para freshwater fisheries
Resumo:
The idea of mechanised fishing on Lake Victoria is not new. Trawling experiments have been carried out in the past by the East African Freshwater Fisheries Research Organisation (EAFFRO), the Lake Victoria Fisheries Service and the Uganda Fisheries Department. In 1950 it was recognised by EAFFRO that commercial possibilities existed in the exploitation of Haplochromis by this gear. However, it was not until 1966 that, by a happy collaboration of the Uganda Fisheries Department and EAFFRO, the vessel 'Darter' was converted into a stern trawler and serious and successful experimentation into trawl fishing commenced. Darter has continued to undertake trawling work ever since and this work was augmented by the arrival in 1967 of the Lake Victoria Fisheries Research Project's vessel 'Ibis'.
Resumo:
Combined effects of lack of firm and effective management measures for years, over exploitation with destructive fishing gears and interspecific competition, particularly among tilapiines and profound effects on the fish stocks of Lake Victoria and Kyoga. It has been proposed that these have been more important in the decline of the indigenous fisheries than predation or competition by Nile perch.
Resumo:
The traditional lucrative fisheries of Lakes Victoria and Kyoga were based on similar multispecies itchthyofaunas. Man's activities on and around these lakes have both directly and indirectly assisted to modify the natural trends and components of the commercial fisheries. The exotic L.niloticus and O.niloticus together with the native R. argentea form the major component of current commercial landings. The total catches are higher but it is not yet clear whether the increase would endure given the fragility of predator/prey systems. The trophodynamics are still modifying and it is not certain how ecosystem function would be influenced. It is, therefore, prudent and desirable to undertake appropriate research investigations in order to guide the multiobjective activities of man on these lakes.
Resumo:
The purpose of this report is to describe very briefly the new program of catch assessment surveys in Lake Victoria. The CAS program, less than a year old is a joint venture of EAFFRO and the Fisheries Departments of the partner states, with assistance from FAO Statistician. The program arose out of the need to establish uniform statistically sound system of data collection in Victoria fisheries, has a topic of discussion at past meetings of the Fisheries Technical Committee.
Resumo:
El Lago Chad ha sido durante varias décadas, una fuente de supervivencia económica para millones de personas que habitan en cuatro Estados a saber; Nigeria, Níger, Chad y Camerún. No obstante, el cambio climático, el aumento acelerado de la población, la explotación insostenible y la mala regulación de los Estados ribereños han sido los principales factores que han dado lugar, en la última década, a la dramática reducción del nivel del Lago Chad. Teniendo en cuenta que los Estados aledaños al Lago, se encuentran inmersos en una Interdependencia Compleja, este nuevo contexto, ha tenido un impacto directo en la región, debido a que ha agravado otras variables económicas, sociales, ambientales y políticas, dejando un ambiente de inseguridad regional. De esta manera, la reducción de la Cuenca del Lago Chad representa una amenaza compartida que vincula estrechamente a Nigeria, Níger, Chad y Camerún, lo que permite vislumbrar la existencia de un Subcomplejo de Seguridad Regional.
Resumo:
O recurso pesqueiro da bacia do rio Cuiabá, um dos mais importantes tributários da bacia do Alto Paraguai, formadora do Pantanal, foi estudado a partir dos dados de desembarque de pescado obtidos no Mercado do Porto de Cuiabá, Mato Grosso, Brasil. São descritas a composição e procedência das capturas para os anos de 2000 e 2001. O rio Cuiabá é a fonte dominante de pescado para a cidade de Cuiabá, mas uma parte do pescado comercializado localmente é oriunda do rio Paraguai. Além disso, atualmente o pescado vem de regiões mais distantes da zona urbana. Constatou-se que a pesca incide basicamente sobre espécies migradoras. As principais espécies capturadas foram os pimelodídeos pintado -Pseudoplatystoma corruscans, cachara -Pseudoplatystoma fasciatum e jaú -Paulicea luetkeni e os caraciformes pacu -Piaractus mesopotamicus, piraputanga -Brycon microlepis, piavuçu -Leporinus macrocephalus e dourado -Salminus brasiliensis. Os grandes bagres (Pimelodidae) foram os responsáveis por 70% do pescado desembarcado no período de estudo, dentre os quais o pintado foi a espécie mais capturada. Os dados indicam que as capturas atuais estão bem aquém daquelas registradas no início da década de 80. Além disso, apesar do número e composição de espécies capturadas serem similares àqueles da década de 80, a distribuição da abundância mudou. Atualmente a pesca captura mais espécies carnívoras do que espécies de níveis tróficos inferiores. Estes achados não podem ser creditados somente a sobrepesca, mas parecem resultar de uma complexa interação entre degradação ambiental, mudanças na preferência de mercado e medidas legais restritivas à pesca.
Resumo:
Gillnets are popularly used in commercial fishing on both Lake kioga and lake Victoria. On Lake kioga the legal mesh size is from 4½ (114) upwards while on Lake Victoria, a multifishery lake, various mesh sizes are in operation. However, the fishermen on these lakes still use the smaller meshes to be able to harvest certain categories of fish especially Oreochromis species group whose catch rates are already on the decline due to either use of small mesh size nets, high fishing pressure and to L.Kioga in particular, predation by lates niloticus.
Resumo:
A statistical comparison of standing stock density estimates (Kg/hectare) from 26 UNDP/FAO 1%9 thru 70 and 63 EAFFRO 1976 bottom trawl surveys revealed the following; 1) Statistically significant differences between mean density values at 4 of 7 depths {4-9 to 30-39 m}. 2) The 1969 thru 70 UNDP/FAO Values were higher at the 4 levels. 3) No statistically significant menn density value differences at 3 depths (40-49 to 60-69 m), but decreased values for the 1976 EAFFRO survey at 40-49 and 50-59 m depth. It was concluded from these comparisons that no capital investment should be made into a trawler industry for fish meal production in the Kenya waters of Lake Victoria until further bottom trawl surveys can be conducted to either substantiate or disapprove these differences over the six year time span.
Resumo:
A casual study of the hydrological map of Uganda would convince every serious fisherman and fisheater that he is most favoured to be in Uganda. The extent and distribution of the country's aquatic system plus the rich variety of fish species there is promises a fishery potential of considerable magnitude: The open waterways comprised by the Uganda portions of Lakes Victoria, Albert and Edward; and Lakes Kyoga, George plus minor lakes Wamala, Kijanebarora, mutanda, etc. occupy about 15% of the total surface area (91,000 m2; Depart. Land Survey, 1962). Most of the nation's fish supplies are currontly from this source. 1.2. A rich network of permanent and seasonal rivers and streams filling and/or emptying various water systems covers most of Uganda. This aquatic network is associated with a fish fauna whose immense significance as a source of protein is perhaps better appreciated by the local subsistance fisherman and consumer than by the fisheries scientist and manager in this country. Many species of this fish fauna have strong affinities with the open water systems while some are typically riverine. 1.3. Then there are wetlands composed mainly of expanses of swamp, but including some areas of bog. These cover about 2% of the country. While the variety of fish fauna found here is limited by the rather hostile nature of the environment (comparatively de-oxygenated under a canopy of dense stands of emergont vegetation) several specialised fishes e.g. Clarias spp. and Protpterus aethiopicus (Kamongo) occur here. Availability of permanent and seasonal sources of water, well distributed throughout most areas of Uganda, opens up immense potential for a variety of aquaculture practices. However, while active exploitation of much of these fishery resources is currently underway, important questions regarding the magnitudes of the various resource potentials and dynamics, and about suitable levels and modes of exploitation, are yet unanswered. These gaps in knowledge go about the fishery resources of Uganda would hinder formulation of adequate development and management schemes. This short paper examines some of the above problems and suggests some approaches towards balanced oxploitation and management of the fisheries of Uganda.
Resumo:
The Artisanal Fisheries Rehabilitation Project (AFRP) Uganda Freshwater Fisheries Research Organisation (UFFRO) Survey was conducted during January - March 1989. The aim of the survey was to evaluate the impact of the AFRP on the national fisheries, assessing the current catch levels, and determining the socio-economic position of the fishermen. On the catch assessment, the survey collected information more specifically on the following: (i) Fish production in Uganda by major species groups. (li) Size structure of the harvested fish. (iii) Catch per unit of effort (CPUE) for the major fish species.
Age, growth, tagging of tilapia spp. and reproductive biology of siluroid catfishes in Lake Victoria
Resumo:
This report encompasses the time period 1 September 1973 through 31 July 1975. The research Officer's tour of duty officially terminated 30 September 1975, consisting of a regular 2-year tour of duty with three month extension of contract. During this time research into age and growth of several tropical species of fishes was conducted. In addition a closely related tagging program was initiated in order to determine both growth and movements of fishes. Lastly, some effort was directed towards aspects of the basic biology of several of the siluroid catfishes. This report delineates the relative effort into and success of the various research projects; presents results of research not previously offered, summarizes findings, and makes recommendations for future research endeavour. Two annual reports along with quarterly reports up to 30 June 1975 have been produced and are on file both at Headquarters in Jinja and the Kisumu Sub-station. These only will be referred to in some instances and built upon in others. Opinions offered, conclusions drawn and recommendation given within this report are solely those of the research officer employed in an official capacity for E.A.F.F.R.O.
Resumo:
The 2012 Public Alligator Hunting Season marked the fifth general alligator hunting season after a closure of nearly 40 years. This year’s public hunt, utilizing a random computer drawing, was open to all applicants, including nonresidents, and was conducted on public and private lands (not enrolled in the Private Lands Program) from the Midlands to the coast. A total of 321 applications for the WMA Alligator Hunt were received, 89.1% from residents, the remainder from eleven other states. The 2012 season began at noon on September 13th and ended at noon on October 10th. This booklet also shows the season results of the hunt and recommendations for the next year's hunt.
Resumo:
The 2013 Public Alligator Hunting Season marked the sixth general alligator hunting season after a closure of nearly 40 years. This year’s public hunt, utilizing a random computer drawing, was open to all applicants, including nonresidents, and was conducted on public and private lands (not enrolled in the Private Lands Program) from the Midlands to the coast. A total of 222 applications for the WMA Alligator Hunt were received, 89.1% from residents, the remainder from eleven other states. The 2013 season began at noon on September 14th and ended at noon on October 12th. This booklet also shows the season results of the hunt and recommendations for the next year's hunt.
Resumo:
This booklet was developed to provide basic information regarding the alligator hunting season and what hunters will need in order to familiarize themselves with taking alligators. It includes common hunting techniques, safety tips, how to harvest an alligator, requirements for processing an alligator, and how to care for an alligator hide.