Information zum nationalen Fischereidatensammlungsprogramm

The EU-Commission has started an initiative to improve the quantity and quality of fishery data. This will improve the quality of fish stock assessments and is expected to implicitly enhance the quality of stock management. By the relevant regulations 1543/2000 and 1639/2001 member states are obliged to establish national programmes for the sampling of data necessary to evaluate the situation of fishery resources and the fishery sector. In this article the German national data sampling programme is described.

Einfluss von Größen und Fangzeit auf das Fettsäuremuster von Sardellen

Fatty acid composition of fish changes according to season, the catching area, the size, the sexuality, the physiological condition and the quantity of fat. The fatty acid composition was evaluated according to size and the catching season of anchovies Engraulis encrasicolus (L. 1758). It was observed that polyunsaturated fatty acids increasmed to highest level and saturated fatty acids decreased to lowest level in March. On the other hand, in April, it was observed that the saturated fatty acids increased to its highest level, monounsaturated fatty acids decreased to its lowest level.

Drying of fish--factors to consider

Although one of the best possibilities for raising the animal protein of the diets of Nigerian is to increase the consumption of fish; particularly through the use of several methods of long term preservation techniques, such as drying, no radical approach has yet emerged. Although, a great deal of the artisanal fish catch is dried for the huge consumer and distant markets, the traditional methods of fish preservation need improvements to cope with demand for increased quantity, shelf-stable, and improved quality of fish products. The paper discusses drying requirements, heat and mass transfer, consumer acceptance, fuel sources, storage and marketing of dried fish products; and suggest ways and means of structurally transforming the artisanal technology of fish drying

Suitability of calorie fortified diets for improving the production of Clarias gariepinus broodstock and fry

The findings are presented of an experiment conducted to determine the adequate level of calorie in diets that is necessary to bring Clarias gariepinus female broodstock to grand stage. The effect of different calorie level on the quality and quantity of egg produced by C. gariepinus broodstock and the survival rate of the fry fed the same diets and those fed harvested zooplankton were also investigated

Post-larval feeding of Clarias gariepinus (Burchell, 1802) on cultured zooplankton and artemia diets

The findings are presented of a study undertaken to provide baseline information that may be employed to develop a simplified hatchery technique for postlarval feeding of Clarias gariepinus on zooplankton cultured indoors in small aquaria. Three series of experiments were undertaken to identify the type and quantity of organic manure that would produce maximum densities of zooplankton in the shortest time in indoor cultures. Results suggest the possibility of the culture of natural zooplankton populations for use in larval feeding of C. gariepinus fry. Its effective hatchery application would bring about reduction in the unit cost per fingerling and ensure continuous hatchery operations even in the absence of Artemia cysts

An economic overview of the fish and shrimp production of the Nigeria fish trawling industry under the structural adjustment programme

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

Data collected on tuna spawning survey cruise July 1-20, 1957: data report

Studies of gonads of yellowfin and skipjack tunas (Neothunnus macropterus and Katsuwonus pelamis) carried out by the Inter-American Tropical Tuna Commission indicate that during summer months the offshore area in the region of the Revilla Gigedo Islands is a spawning location for these two species (Schaefer and Orange, 1956). In July of 1957 a cruise "Tuna Spawning Survey" was made aboard the vessel ORCA to make plankton hauls and to collect ancillary data for the primary purpose of surveying abundance of tuna larvae in this region. (PDF contains 17 pages.)

The hydrology of a small fish pond at the University of Agriculture, Makurdi Experimental Fish Farm

The monthly and seasonal water requirements of a small fish pond (0.068ha; maximum capacity of 613.83m super(3)) at the University of Agriculture, Makurdi Fish Farm (Benue, Nigeria) were determined during the period of February to August 1996. The sources of water for the pond were rainfall, (103.4cm), run-off (6.3cm) and regulated inflow (95.0cm). The water loss for the period were Evapotranspiration, (106.74cm), Seepage (71.64cm) and regulated discharge (25.00cm). Evapotranspiration was identified as the main source of water loss while rainfall was the major source of water gain. The mean monthly water deficit was 24.56~c11.43cm while the mean monthly surplus was 9.84~c8.05cm. The quantity of water required to maintain the optimal water level in the pond was 474.00m super(3). Preliminary water budget of the study area showed that rainfed aquaculture can be effectively carried out at Makurdi during the months of June to October with supplementary inflows during the dry season months

Effect of fish meal in formulated diet on the growth of Heterotis niloticus in semi-intensive pond culture system

The aim of the investigation is to know the percentage of fish meal required to support the best growth of Heterotis niloticus in a semi intensive pond culture system. To achieve this, feed was formulated with equal percentages of blood meal, and corn meal and varying levels of fish meal. The experiment was in four treatments. Results showed that the mean weight gained was directly proportional to the quantity of fish meal made available to the fish fence 31.58g, 33.79g, 45.15g and 51.24g were recorded for treatments I, II, III and IV respectively. Result from this study when compared with previous works, shows that size of the water body to a greater extent affects the growth. The availability of fish meal in the feed made it more acceptable to the fish and hence a commensurate conversion in to flesh. The analysis of variance showed that there is significant difference in the growth performance in the treatments

The effects of brood stock size on the economy of catfish (Clarias anguillaris) fry production using the hormone induced natural breeding technique

89 ripe female brooders of the catfish, Clarias anguillaris (Body wt. Range 150g-1, 200g) were induced to spawn by hormone (Ovaprim) induced natural spawning technique over a period of 10 weeks. Matching ripe males were used for pairing the females at the ratio of two males to a female. Six ranges of brood stock body weights were considered as follows; <200g; 200g-399g; 400g-599g; 600-799g; 800g-999g; > 1000g and the number of fry produced by each female brooder was scored/recorded against the corresponding body weight range. The number of fry per unit quantity of hormone and the cost of production a fry based on the current price of Ovaprim (hormon) were determined so as to ascertain most economic size range. The best and most economic size range was between 400g-599g body weight with about 20,000 fry per ml of hormone and N0.028 per fry, while the females above 1000g gave the poorest results of 9,519 fry per ml of hormone and N0.059 per fry. For optimum production of Clarias anguillaris fry and maximum return on investment female brooders of body weights ranging between 400g-599g are recommended for hormone induced natural breeding exercises

Adoption of simple technologies for poverty alleviation

Several technologies have been disseminated to the rural populace of which few were adoptable while others were above their reaches. The adoption-rejection behaviour of the people of Monai community formed the basis for this study. Twenty women fish processors were interviewed using standard questionnaire. The study discovered that the women fish processors used the new introduced Better Life Programme Banda in rotation for even coverage. The use of new Banda has a positive effect on the quantity of fish processed and income. Additional two basins were processed on weekly basis with an income of N1,000.00 over the previous processing technology. No women processor however had the new Banda on individual basis for cost. Hence rural people adopt a technology that is cheap and simple but conforming to their traditional practices and values. Therefore any innovation intended for the rural populace should take cognizance of their socio-economic and cultural factors

The effects of brood stock size on the economy of catfish (Clarias anguillaris) fry production using the hormone induced natural breeding technique

89 ripe female brooders of the catfish, Clarias anguillaris (Body wt. Range 150g-1, 200g) were induced to spawn by hormone (Ovaprim) induced natural spawning technique over a period of 10 weeks. Matching ripe males were used for pairing the females at the ratio of two males to a female. Six ranges of brood stock body weights were considered as follows; <200g; 200g-399g; 400g-599g; 600-799g; 800g-999g; > 1000g and the number of fry produced by each female brooder was scored/recorded against the corresponding body weight range. The number of fry per unit quantity of hormone and the cost of production a fry based on the current price of Ovaprim (hormon) were determined so as to ascertain most economic size range. The best and most economic size range was between 400g-599g body weight with about 20,000 fry per ml of hormone and N0.028 per fry, while the females above 1000g gave the poorest results of 9,519 fry per ml of hormone and N0.059 per fry. For optimum production of Clarias anguillaris fry and maximum return on investment female brooders of body weights ranging between 400g-599g are recommended for hormone induced natural breeding exercises

The influence of blue-green algae on development of the zooplankton. [Translation of: Byull.mosk.Obshch.Ispyt.Prir.(Biol.) 67, 128-131, 1962]

Many have observed the reduction of the quantity of zooplankton in the presence of water blooms. It is known that in seas zooplankton as it were avoids places of accumulation of blue-green algae. By observations on one of the tributaries of the Rybinsk reservoir - the River Shumorovka - the authors tried by simultaneous collections to trace the changes in numbers, not only of zoo- and phytoplankton but also of bacteria. The plankton was collected by quantitative nets with suitable numbers of gauze and bacteria were taken account of by the method of direct calculation on membrane filters. It can be seen that the development of blue-green algae appears as an important factor, determining not only the intensity but also the direction of the process of production of zooplankton.

On the nutrition of Polyphemus pediculus (L.). [Translation from: Trudy Instituta Biologii Vnutrennykh Vodnany 12(15) 170-174, 1966.]

Many sides of the biology of Polyphemus pediculus are adequately studied at the present time. Most complicated is the question of its feeding. Dissection does not give an idea of the composition of the food, since Polyphemus strongly grinds its food with its mandibles. For clarification of the composition of the food of Polyphemus pediculus, the authors carried out in July and August 1962 a series of experiments with the application of radio-carbon methods in order to judge the degree of utilization of one or other foods by the quantity of C14, accumulated in the body of the crustacean after feeding. Particular attention in these experiments was given to the question of the possibility of the utilization by polyphemus of plant food - bacteria, algae and detritus.

Rhythms of division of some algae in situ and in laboratory culture. [Translation from: Studii Cerc.Biol.(Bot.) 21, 61-65, 1969. ]

The rhythm of division of 9 species belonging to different groups of algae were analysed in situ and in the laboratory. The research which developed in different environmental conditions attempted to establish the capacity for multiplication and assimilation of chlorophyll on the part of the algae under study with a view to placing them in a culture. The results obtained showed that the green multicellular algae (eg. Ulothrix) and the blue algae (eg. Lyngbya, Oscillatoria) are able to produce an appreciable quantity of dry matter, just as the unicellular algae. At the same time it arises that amongst the numerous factors of the environment, temperature plays one of the most important roles in the process of multiplication.