Fisheries Eco-Biology of Beel Koshba of Naogaon District

Abstract

The present study was conducted in Beel Koshba of Naogaon district on the fisheries eco- biology during the period July, 2005 to June, 2007. The physical conditions of Beel Koshba consisted of air temperature, rainy days, rainfall, humidity, water temperature, water depth and water transparency were 26.07±4.56°C, 9.54±8.55 days, 113.93±114.01 mm, 79.33±7.94%, 25.365.12°C, 204.96 110.36 cm and 30.91+6.78 cm respectively. The chemical parameters of total hardness, alkalinity, pH, DO, CO2 and ammonia were 146.60±13.36 mg/l, 143.30±9.33 mg/l, 7.05±0.75, 6.03±1.08 mg/l, 8.64±0.88 mg/l and 0.73 0.31 mg/l respectively. The magnitude of monthly and seasonal variations of the physico-chemical factors indicated the eutrophic nature of the beel. A total of 54 species of different plants were found surround the beel area. Eight species of sub-merged, nine species of floating, 19 species amphibian vegetations were found in the beel. A total of 126 species of phytoplankton belonging to the 54 genera and 73 species of zooplankton belonging to the 42 genera were recorded from the beel. A total of 103 species of fish belonging to the 52 genera of 20 families, 10 orders under Osteichthyes class were recorded. Food and feeding habits, seasonal availability, breeding season, habitat and economic importance were also studied in the Beel Koshba. Identified annelids, arthropods, mollusks, amphibian, reptiles, aves and mammals were 8, 11, 15, 8, 21, 40 and 12 respectively. Among these 16 species of edible fisheries items were identified. It has been observed that the abundance of fishes is decreasing day by day due to natural and man made causes and other environmental factors. Some of the species are extinct (Nandus nandus, Chaca chaca), some of the species are threatened to extinction (C. marulius, Bagarius bagarius) in the northwest region of Bangladesh. Disease symptoms of the 12 fish species were studied. The symptoms of the diseases were 13 in number. The symptoms of dermal lesion was observed in all of the infected fish species (12 species), followed by ulcer (11 species), Epizootic Ulcerative Syndrome (10 species), tail and fin rot (6 species), red spot (6 species), scale loss (5 species), deformed (4), dropsy (3 species), gill rot (3 species), hemorrhage (3 species), black spot (3 species), tumour (2), white spot (2 species). The incidence of diseases were 8.08%, 19.42%, 17.08%, 13.42%, 9.58%, 8.00%, 7.25%, 16.17%, 17.42%, 5.42%, 10.08%, 14.92% in the species Carla catla, Channa punctatus, Channa striatus, Cirrhinus mrigala, Heteropneustes fossilis, Labeo bata, Labeo rohita, Mystus armatus, Mastacembelus pancalus, Mystus vittatus, Puntius sarana, Puntius ticto respectively. The overall incidence was 12.24%. The highest incidence was observed in Channa punctatus (19.42%) followed by Mastacembelus pancalus (17.42%) and Channa striatus (17.08%). The lowest incidence observed in Mystus vittatus (5.42%). The occurrence of diseases was highest in February (24.75%) followed by March (23.92%), January (23.42%), April (19.83%), December (19.75%), November (18.17%), October (4.75%), September (4.00%), May (2.92%), August (2.75%) and July (2.58%). The diseases were found in the month of July-May during the study period July 2005-June 2007, peak in the months of January-March. In case of environmental hazards, natural hazards (flood, drought, tornado and earthquake) and man made hazards (degradation of water quality from agriculture sector, industrial waste and fishermen community) were observed. Environmental hazards from fishermen community were observed on the basis of age group, family size, income group, investment, educational qualification, sanitary system, land ownership, fuel use pattern, housing pattern etc. It was found that the fishermen were the highest (32%) in 21-30 age group and the lowest (4%) in 61-70 age group. In case of total population, 11-20 age group people was the highest (25.66%) and accordingly the lowest (1.54%) in 61-70 age group. Daily income of the fishermen was the highest (50%) in Tk. 61-90 income per day group and the lowest (2%) in above the Tk. 151 group. The highest (36%) investments were in Tk. 2001-4000 group and the lowest (8%) were in highest investment Tk. 8001-10,000 group. The fishermen were mostly illiterate (68%) and 25% near to illiterate i.e. below class five group. Only 1% was secondary school certificate and above. In case of subsidiary occupation, the highest (44%) fishermen sell their labour on daily basis, 24%, 12% and 8% were engaged in agriculture, fish trading and other works respectively. Family type was mostly nuclear. Eighty seven percent families have below 6 members. Only 1% family has above 9 members. In case of land ownership pattern 6% fishermen were absolute land less. Seventy percent fishers have no agricultural land, they have only ancestral homestead. Only 24% fishers have a little piece of agricultural land. Overall average per family has only 0.061 hectare land. They use Lakri, Waste straw, Dry leaves, Nanda and Bhusi as fuel for cooking. Most of the fishes (90%) caught by the fishermen was sold in paikari form and always they set a less amount than expected one. The fishermen have no adequate training (only 8% ). They do not know (88%) the fisheries law. They showed interest (99%) to get training. Seventy percent Muslim and 30% Hindu community were engaged in the occupation of fishing.