On farm trial of Bangladesh Fisheries Research Institute (BFRI) evolved two aquaculture technologies

Two BFRI evolved aquaculture technologies - integrated rice fish farming and carp polyculture with over-wintered fingerlings under different stocking densities were tested during 2003-04. The study was coordinated with two local NGOs namely NICHAITA and JNDP, Muktagacha, Mymensingh. Integrated rice fish farming technology was demonstrated in 9 plots each having an area between 60-100 dec. during boro season. Fifteen days after transplantation of rice seedlings, fingerlings of rajpunti (Barbodes gonionotus) of 7-10 g of individual weight were stocked in the rice fields at the density of 3,000 (T1), 3,750 (T2) and 4,500/ha (T3). The corresponding final weight of fish after three and half months in treatments 1, 2 and 3 were 110±14.21, 101±16.55 and 86±22.28 g, respectively. The mean weight of fish in treatments 1 and 2 was significantly higher than treatment 3. Fish production obtained from treatments 1, 2 and 3 were 218.16±18.29, 239.70±25.11 and 236±24.66 kg/ha, respectively. On-farm demonstrations of carp polyculture using over-wintered fingerlings rohu (25-28 g), catla (24-26 g), mrigal (21-26 g) and grass carp (20-24 g) under different stocking densities were undertaken in nine earthen ponds (1,200-1,600 square meters) for a period of six months at three different stocking densities. The stocking densities of treatment 1 (T1), treatment 2 (T2) and treatment 3 (T3) were 2,000, 3,000 and 4,000/ha, respectively. Fish were fed with rice bran and mustard oil cake (3:1). Soft green grass and banana leaves were provided mainly for grass carp. At harvest, the production obtained in treatments 1, 2 and 3 were 2,325±74.75, 2,620±49.66 and 2,982± 171.52 kg/ha, respectively. The results demonstrated higher growth of fish in treatment 1 than those of treatments 2 and 3. However, treatment 3 contributed relatively higher production than those of treatments 1 and 2, whereas, highest net benefit was received from treatment 2.

Adoption, productivity and profitability of rice-fish and fingerling culture in three selected districts of Bangladesh

The study aimed to investigate the productivity and profitability of rice-fish farming. It also determined the factors affecting rice-fish and fingerling production in Bangladesh. Among the total respondents about 55% were involved in rice-fish farming, 37% in pond fish culture and rest 9% in fish nursery. Integrated rice-fish farming contributed about 83% of the annual farm income in Comilla while it was about 20% in both Kishoregonj and Chandpur districts. Among the different farming systems integrated rice-fish culture and rearing fingerlings in the nursery pond were more profitable at the farm level. Farmers earned a net return of Tk. 49,714/ha from integrated fish culture with boro rice while the net return of boro rice-alone was only Tk. 11,179/ha. This indicated that farmer could earn 218% higher net return from integrated rice-fish farming than that of boro rice only farming. Moreover, integrated rice-fish culture also reduced pesticides cost to about 77% and weeding cost to about 51% in boro season. Fingerling nursing earned highest net returns among the three technologies.

Studies on kraft paper used for liners and corrugating media of shipping containers for frozen shrimp

An examination was made of the physical properties of kraft paper used for liners and corrugating media of shrimp shipping containers in India. Findings stress the need for use of virgin grade kraft paper and adequate waxing treatment on both sides for water proofing.

Potential risks of contaminants with specific reference to mercury

Fresh water and fish are important to the people who live in the Lake Victoria region therefore the quality of the water and fish is of major importance (Johnson & Odada, 1996). It is well known that dirty water and spoilt fish can lead to poor health and lower standards of living, and that quality can be affected by the pollution in the environment. Even though Lake Victoria is very large, it is relatively shallow and the water remains in the lake basin for a long time (Bootsma & Hecky, 1993). There are a number of environmental issues in Lake Victoria, including water hyacinth~over-population and increased farming causing problems with the lake ecosystem. All these factors combine to keep contaminants within the lake for long time, which will lead to gradually increasing concentrations in the lake. Pollution is a term that covers a wide variety of chemicals and physical changes and their adverse effects on the environment. Here we focus on contaminants, which are unwanted chemicals introduced to the environment. Contaminants include a very wide variety of chemicals, both man-made and natural, for example, mercury, pesticides and herbicides, heavy metals, and natural plant and algae toxins. Many contaminants do not always lead to adverse effects immediately, but can gradually induce long-term problems leading to chronic illnesses and physical damage. A few contaminants have very rapid impacts resulting in immediately obvious changes such as death or injury. Sources of contaminants are varied. Contaminants can get in the lake by the way of agricultural treatment of crops near the lake, industrial effluent, intentional introduction such as fish poisoning byfishermen, natural sources such as heavy metals from particular types of rocks, and even some plants naturally release their toxins. Contaminant sources are not always found near Lake Victoria.

On the ecology and explorations of the fisheries of an East African rift valley lake, Part 1: On the bionomics and population structure of Tilapia nilotica Linnaeus 1757 in Lake Baringo, Kenya

An ecological survey of the fisheries of Lake Baringo, Kenya was carried out between August, 1972 and August, 1973. The bionomics and population structure of T. nilotica is described. Sampling was done with multifilament gillnets of graded mesh sizes from 51 mm to 178 mm in approximately 12.5 mm increments. The Lake was divided into three sampling and ecologically different zones - the south, central and north zones. The size range of T. nilotica of both sexes caught was between 5 and 27 cm (mode 16 cm) with a mean length of 16.07 cm. For all the collections, males dominated (55.3%) and a higher proportion of males were caught in January, August and November. The smallest mature male and female was 9 and 10 cm respectively. Males grow faster and mature at larger sizes than females. 50% of all males and females mature at 17.4 and 16:4 cm respectively. The periods of intense spawning were between August and October and January to April. The Tilapia were feeding best in central and north zones and the feeding intensity was reduced in January. Two endoparasites Contracaecum sp. and Clinostomum sp. were isolated from the Tilapia. The "condition" of the fish was better in the north than in the other two zones.