52 resultados para Participation Rate

em Aquatic Commons


Relevância:

30.00% 30.00%

Publicador:

Resumo:

One major aspect of the poverty status in Nigeria is the high rate of unemployment with the attendant economic in capacity, which in turn is responsible for the persistent problem of malnutrition over the decades. This paper is focused on how women can be empowered for better productivity in fish culture enterprises, seeing that women have been active in different aspects of agricultural production. They also sustain more than half of the developing countries such as Nigeria. Some problems being encountered by would be women fish farmers and suggestions on how women participation in fish and shellfish culture enterprises can be enhanced are proffered. The major ones being those sustainable policies by the Government State ADPs and NGOs are applied to ensure adequate motivation of women for fish culture enterprises

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Giant cutgrass ( Zizaniopsis miliacea (Michx.) Doell. & Asch.), a tall emergent grass native to the southeastern United States, was studied in Lake Seminole where it formed large expanding stands, and Lake Alice where it was confined to a stable narrow fringe.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In selecting an excess temperature at which to operate a power plant cooling system it has been customary to consider only thermal stresses and to use the ratio of the number of organisms killed to the number of organisms entrained. This frequently leads to the selection of a low excess temperature, AT, which, in turn, requires a large volume flow of cooling water. When mortalities due to physical and chemical stresses are included and the total number of entrained organisms killed is taken as the measure of the environmental damage, it becomes evident that the choice of a low excess temperature is seldom, if ever, best.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Throughout the Asia-Pacific region capture fisheries and certain less intensive forms of aquaculture can and do play a vital role in livelihoods management, food security, and health and nutrition. Knowledge and experience exist that could be more effectively used in policy for poverty alleviation. (PDF contains 89 pages)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

ENGLISH: The present paper describes a new method for estimating the shedding rate of tags. The method utilizes not only data on tagging and recovery of fish marked with two tags but also data from those marked with one. One important advantage of the new technique is that the estimates of the shedding rates are free from distortion caused by variations in fishing intensity during the total recovery period. The idea of this method appears to be implicit in a short note by Gulland (1963). This technique has been applied to the data obtained by the Inter-American Tropical Tuna Commission in a tagging cruise off the west coast of southern Baja California, during June 1963, at which time both single and double-tagged yellowfin tuna were released. Details of the tagging procedure and equipment have been described by Fink (1965b). The results presented in the present paper are for yellowfin tuna tagged with dart tags. Estimates of shedding should be made separately for each species investigated and also for each type of tag used, since these rates may be variable and often unexpectedly high (Springer and McErlean 1961, Chadwick 1963). SPANISH: El presente estudio describe un nuevo método para estimar las tasas del desprendimiento de marcas. El método emplea no solamente los datos sobre la marcación y recobro de peces marcados con dos marcas, pero también datos de los peces marcados con una marca. Una ventaja importante de la nueva técnica, es que las estimaciones de las tasas de desprendimiento son libres de alteración, causada por las variaciones en la intensidad de pesca durante el período total de recobro. La idea de este método parece ser implícita en un breve apunte por Gulland (1963). Esta técnica se ha aplicado a los datos obtenidos por la Comisión Interamericana del Atún Tropical, en un crucero de marcación efectuado frente a la costa occidental al sur de Baja California, en junio de 1963, tiempo en el cual fueron liberados atunes aleta amarilla marcados tanto con una como con dos marcas. Los detalles del procedimiento de la marcación y del equipo usado han sido descritos por Fink (1965b). Los resultados presentados en este estudio, pertenecen al atún aleta amarilla marcado con marcas de dardo. Las estimaciones del desprendimiento deben efectuarse separadamente para cada especie que ha sido investigada y también para cada tipo de marca usado, ya que estas tasas pueden ser vaiables, y a menudo inesperadamente altas (Springer y McErlean 1961, Chadwick 1963). (PDF contains 20 pages.)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In a survey conducted to find out the status of integrated rice-cum-fish culture in Niger State, Nigeria, 0.37 ha of Fadama wetlands was utilized for rice-cum-fish culture and at experimental stage. In the case study of this rice-cum-fish model, the Nile Tilapia (Oreochromis niloticus) was involved. The result was that 1,4720 kg/ha/yr could be produced using chick manure application under rice-cum-fish culture model. The available records reveal that 233,079 ha out of 495,000 ha of estimated Fadama in Niger State was used for rice cultivation in 1997. If 233,079 ha were to be used for integrated rice-cum fish culture, it is estimated that 343,092 mt of fish (Oreochromis niloticus) could be produced per year. The fish demand in Niger State in 2002 was 50,000 mt. The NPK application under rice-cum-fish production gave the best rice production estimated at 43,968.0 kg/ha/yr. The percentage increase in rice yield as well as increase in net income due to introduction of fish was 10.1 % and 54.4% respectively. The culture system is therefore recommended for adoption towards greater participation in aquaculture development by the farmers

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A-ten-week feeding trial was carried out to evaluate the growth and survival rate of Oreochromis niloticus fed with varying percentage levels of Leucaena leucocephala leaf meal based diets. The substitution rates of L.leucocephala leaf meal for groundnut cake in the various diets were 0% - Diet 1, 25% - Diet 2, 50% - Diet 3 and 75% - Diet 4. Ten fries with an average weight of 0.44g were stocked at the rate of 10 fish per bowl and fed at 5% body weight. Diet 1 with 0% inclusion of Leucaena leaf meal gave a significant difference (P>0.05) in growth and survival rate compared with diets 2, 3 and 4. The water quality parameters recorded were appropriate for fish culture

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A-ten-week feeding trial was carried out to evaluate the growth and survival rate of Oreochromis niloticus fed with varying percentage levels of Leucaena leucocephala leaf meal as a substitute for groundnut cake. The levels in the various diets were 0% - Diet 1, 25% - Diet 2, 50% - Diet 3 and 75% - Diet 4. Ten fingerlings with an average weight of 0.44g were stocked at the rate of 10 fish per bowl and fed at 5% body weight. Diet 1 with 0% inclusion of leucaena leaf meal gave a significant difference (P>0.05) in growth and survival rate compared with diets 2, 3 and 4. The water quality parameters recorded were appropriate for fish culture

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Within natural resource management, there is increasing criticism of the traditional model of top-down management as a method of governance, as researchers and managers alike have recognized that resources can frequently be better managed when stakeholders are directly involved in management. As a result, in recent years the concept of co-management of natural resources, in which management responsibilities are shared between the government and stakeholders, has become increasingly popular, both in the academic literature and in practice. However, while co-management has significant potential as a successful management tool, the issue of equity in co-management has rarely been addressed. It is necessary to understand the differential impacts on stakeholders of co-management processes and the degree to which diverse stakeholders are represented within co-management. Understanding the interests of various stakeholders can be a way to more effectively address the distributional and social impacts of coastal policies, which can in turn increase compliance with management measures and lead to more sustainable resource management regimes. This research seeks to take a closer look at the concepts of co-management and participation through a number of case studies of marine protected areas (MPAs) in the Caribbean. (PDF contains 4 pages)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Women, all over the world have contributed in various ways to the social, political and economic development of the Society. In fact, the World Resource Institute recognizes that "women have profound and preserve effect onn the well-being of their families, communities and local ecosystems" (Gamble and Well 1997:211). Women constitute more than 50 percent of the Agricultural (Fisheries being a sub sector), labour force. A study on Women in Fisheries showed that they participate in all aspects of the sector (capture, culture, processing, marketing research, training and Extension services). This paper reports the result of the study on women's contributions in the development of the Fisheries Industry particularly their roles in Fish Food Security, Poverty Alleviation and high rates of women's adoption of Fisheries technologies. The Case-study research methodology is used to study the "How" and "Why" Women's Contribution in Fish Food Security and Poverty Alleviation is at the index level recorded for the gender. The study made use of "Case Study" Research Instrument; documents, interview, artefacts, direct observation and archival records. The sampling techniques were purposive for research audiences and simple random for fisher-folks in the chosen locations. Analysed data showed among others that in Fisheries Research women occupy very important positions as Heads of Division/Section, Fisheries Liasion/Extension Officers and Fisheries Laboratory Chiefs etc. The paper also gave results of women production, processing, marketing and other services statistics; it also discusses the "whys" of women's low capacity in fisheries development of the nation and finally suggested ways in improving women's optimal capacity utilization in fisheries development

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The growth response, feed conversion ratio and cost benefits of hybrid catfish, Heterobranchus longifilis x Clarias gariepinus fed five maggot meal based diets were evaluated for 56 days in outdoor concrete tanks. Twenty-five fingerlings of the hybrid fish were stocked in ten outdoor concrete tanks of dimension 1.2mx0.13mx0.18m and code MM sub(1)-MM sub(5) in relation to their diet name. Five isonitrogenous and isocaloric maggot meal based diets namely MM sub(1)-0% maggot meal, MM sub(2)-25% maggot meal, MM sub(3)-50% maggot meal, MM sub(4-)75% maggot meal and MM sub(5-) 100% maggot meal were used for the experiment. The higher the proportion of maggot in the meal, the higher the ether extract and crude fiber. No significance difference P>0.05 exists between ash content of the experimental diets. Diet MM sub(2) had the best growth performance and highest MGR with a significant difference P<0.05 with other diets fed fish. No significance differences P>0.05 exists between the growth parameters for diets MM sub(1), MM sub(3), and MM sub(4). A positive correlation (r=1.0) exists (P<0.05, 0.25) between the growth parameters for the different experimental diets. Highest correlation r super(2)=0.9981 exists P<0.05 between MGR within the treatments. However, there no significant (P>0.05) difference in expenditure but there is between the profit indices and incidence of cost between the trials. MM sub(2) has the best yield cost and net profit. Without any reservation, inclusion of maggot based meal diet is recommended as feed of hybrid catfish to 75% inclusion for growth and profit incidence

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this report we develop age-length keys and derive age-frequency data. We estimate striped bass and white perch mortality and growth rates, based on the otolith-aging analysis. We also report on hatch-date frequencies of striped bass and white perch larvae, and we discuss environmental effects on recruitment potential.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Abstract Environmental changes may have an impact on life conditions of the fish, e.g. food supply for the fish. The prevailing environmental conditions apply evenly to all age groups of one stock. Small fish have high growth rates, whereas large fish grow with low rates. But, it can be shown on the basis of the von Bertalanffy-growth model that it is sufficient to know only the growth rate of one single age group to compute the growth rates of all other age groups. The growth rate of a reference fish GRF (e.g. a fish with a body mass of 1 kg) was introduced as a reference growth describing the current food condition of all age groups of the stock. As an example a time series of the reference-growth rate of the northern cod stock (NAFO, 3K) was computed for the time span 1979 to 1999. For the northern cod stock it can be observed that environmental conditions caused growth rates below the long-term mean for seven years in a row. After a prolonged hunger period the fish stock collapsed in 1992 also by the impact of fisheries - and this was probably not a coincidence. Now, with the reference-growth rate GRF a simple and handy parameter was found to summarize the influence of the environmental conditions on growth and other derived models and therefore makes it easier to compute the influence of environmental changes within stock assessment. Zusammenfassung Veränderungen der Umwelt können Auswirkungen auf die Lebensbedingungen der Fische haben, z. B. auf das Nahrungsangebot der Fische. Die vorherrschenden Umgebungsbedingungen wirken gleichmäßig auf alle Altersgruppen eines Bestandes, wobei typischer Weise kleineFische hohe Wachstumsraten haben, während die großen Fische mit niedrigen Raten wachsen. Auf der Grundlage des von Bertalanffy-Wachstumsmodells kann gezeigt werden, dass es ausreicht, nur die Wachstumsrate von einer einzigen Altersgruppe zu kennen, um die Wachstumsraten von allen anderen Altersgruppen berechnen zu können. Die Wachstumsrate eines Referenz-Fisches (z.B. eines Fisches mit einer Körpermasse von 1 kg) wurde als Referenz-Wachstum GRF eingeführt, die den aktuellen Zustand des Nahrungsangebots füralle Altersgruppen des Bestandes beschreibt. Als Beispiel wurde einer Zeitreihe der Referenz-Wachstumsraten des nördlichen Kabeljaubestandes (NAFO, 3K) für die Zeitsraum 1979 bis 1999 berechnet. Für diesen Kabeljaubestand war zu beobachten, dass Umgebungsbedingungen für sieben Jahre in Folge Wachstumsraten unter dem langjährigen Mittelwert verursachten. Nach einer längeren Hungerperiode kollabierte dieser Fischbestand im Jahr 1992 auch durch den Einfluß der Fischerei - und dies war sicher kein Zufall. Jetzt, mit der Referenz-Wachstumsrate GRF, ist ein einfacher und handlicher Parameter gefunden, der es gestattet den Einfluss der Umweltbedingungen auf die Wachstumsbedingungen und andere davon abgeleitete Modelle zusammenzufassen. Dies macht es einfach, den Einfluss von Umweltveränderungen innerhalb der Bestandsabschätzungen zu berechnen.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

When salmonid redds are disrupted by spates, the displaced eggs will drift downstream. The mean distance of travel, the types of locations in which the eggs resettle and the depth of reburial of displaced eggs are not known. Investigation of these topics under field conditions presents considerable practical problems, though the use of artificial eggs might help to overcome some of them. Attempts to assess the similarities and/or differences in performance between real and artificial eggs are essential before artificial eggs can validly be used to simulate real eggs. The present report first compares the two types of egg in terms of their measurable physical characteristics (e.g. dimensions and density). The rate at which eggs fall in still water will relate to the rate at which they are likely to resettle in flowing water in the field. As the rate of fall will be influenced by a number of additional factors (e.g. shape and surface texture) which are not easily measured directly, the rates of fall of the two types of egg have been compared directly under controlled conditions. Finally, comparisons of the pattern of settlement of the two types of egg in flowing water in an experimental channel have been made. Although the work was primarily aimed at testing the value of artificial eggs as a simulation of real eggs, several side issues more directly concerned with the properties of real eggs and the likely distance of drift in natural streams have also been explored. This is the first of three reports made on this topic by the author in 1984.