124 resultados para 1988-1994
Resumo:
Brachyuran larvae are the most common zooplankton component of the Manora Channel, Karachi, Pakistan. The identification of these larvae would assist in the assessment of brachyuran species and provide information on percentage composition, occurrence, abundance and breeding habits of the brachyuran species in the Manora Channel area. However plankton caught larvae is not easily identified. An accurate identification of such material is only possible by the comparison with larvae reared under laboratory conditions and documented with illustrations. The identifications for this present study were based on the works of Gurney (1938); Atkins (1954); Chhapgar (1955); Raja Bai (1960); Hashmi (1969, 1970a, b); Baba and Miyata (1971); Kakati and Sankolli (1975); Rice (1975); Kakati (1977); Lim and Tan (1981); Yatsuzuka and Sakai (1984); Fielder, et al (1984); Amir (1989, M. Phil thesis unpublished); Ingle (1992); Siddiqui and Tirmizi (1992); Tirmizi et al (1993); Bano (1999, M. Phil thesis unpublished); Ghory and Siddiqui (2001); Ghory (2002, M. Phil thesis unpublished); Ghory and Siddiqui (2002).
Resumo:
The physical-chemical characteristics of any aquatic ecosystem include pH, conductivity, and temperature, water transparency, nutrient and the chlorophyll-a levels. Physical and chemical factors of any ecosystem determine the type and quality of flora present in it and these forms the basis on which the system operates. The elements required in largest amounts for plant productions are carbon, phosphorus, nitrogen, and silicon, which is important for diatoms as a major component of the cell wall. Nutrients may limit algal productivity in the tropics despite the high temperature there allowing rapid nutrient recycling. Nutrients most likely to be limiting African lakes are nitrogen (Talling & Talling 1965; Moss 1969; Lehman & Branstrator 1993, 1994) and phosphorus (Melack.et al l982; Kalff 1983) while silicon may limit diatom growth (Hecky & Kilham 1988). The objective of the study is to investigate the impact of physical-chemical characteristics on the distribution and abundance of organisms in the major aquatic ecosystems.
Resumo:
This is the first annual report of Fisheries Research Institute (FlRl) under the National Agricultural Research Organization (NARO). NARO was formed by a statute of the government of Uganda in 1992 and became fully operational in 1994. NARO is charged with coordinating and managing national agricultural research in crop. livestock. forestry and fisheries. FIRI is one of the research institutes of NARO. It is charged with generating information and technology to facilitate increased and, sustainable utilization of aquatic resources.
Resumo:
Fish landing data collected by the Kenyan Fisheries Department from the nearshort coastal marine waters from 1985 to 1994 were statistically analyzed to determine trends in the traditional fisher's catch. Over the ten year period a significant decline occurred for total catch and for catches of seven commercially important fish families: Lethrinidae, Siganidae. Lutjanidae, Scaridae, Carangidae, Scombridae and Mullidae. 1994 registercd the lowest catch over ten years. The total catch for all the fish declined from a mean annual catch of 6150 metric tonnes in the 1980's to a mean of 5141 metric tonnes in the 1990's with the catch for 1986 being 2 times higher than that of 1994. Although Mombasa district had the highest mean annual landing, its total landings like that of Lamu and Kwale districts decreased over the years. However, Kilifi district showed a steady increase in catches over the years. The changes in fish landings is thought to be caused by lack of appropriate fishing regulations, leading to overfishing of the lagoonal reefs beyond their maximum sustainable yields.