A socioeconomic and bioeconomic analysis of coastal fisheries of Bangladesh

Bangladesh has an exclusive economic zone (EEZ) of 164 000 km2 and a continental shelf area of 66 440 km2. Artisanal (small scale) fisheries extend from the coast to 40 m while industrial (commercial scale) fisheries operate beyond 40 m depth. The coastal fisheries of Bangladesh exploit a complex multi-species resource. There are 18 demersal and pelagic species, seven species of larger pelagic and 10 shrimp species that are commercially important among the fishes exploited. In 1996 - 97, total fish production reached 1.3 million t with 75% from capture fisheries (0.9 million t) and 25% from aquaculture (0.4 million t). Artisanal fishing operations dominated the marine fisheries, contributing 82% of the total fish production. Information on the gross national product (GNP) and domestic product (GDP) showed that the share of agriculture has been declining over the years. The national income accounting procedure in Bangladesh divides the agriculture sector into crops, livestock, forestry and fisheries. Fisheries contribute to economic development of the country in four ways: (a) helping to achieve high growth rates by creating the necessary value-added; (b) providing employment to a large number of people; (c) adding a large volume of valuable foreign exchange; and (d) providing a cheap source of essential food to lower income people. In 1997 - 98, GNP, GDP and value-added contributions at current prices by the fisheries sector amounted to US$35716 mil, US$34062 mil and US$1808 mil, respectively. Of the total export value of US$1217 mil, 8.5% (US$104 mil) came from fish and fish products. In terms of food consumption, fish ranks third as the most important food item with a mean per capita consumption of 8.36 kg╖year-1. There are three major fishing fleets in Bangladesh namely, the trawlers, the mechanized boats and the non-mechanized boats. In 1972 - 73, there were 10 trawlers and 200 mechanized boats operating in the fishing grounds of Bangladesh. This expanded to 54 trawlers, 3317 mechanized boats and 14 014 non-mechanized boats in 1996 - 97. Trawlers were divided into 41 shrimp and 13 fish units while mechanized boats included gillnet, set bag net and long-line gear. Non-mechanized boats are also used for gillnet fishing, set bag net fishing, long-line fishing, trammel net fishing and other gear. The Schaefer and Fox Models were used to estimate the maximum sustainable yield (MSY) for the fisheries of Bangladesh. Results of these bioeconomic models show that MSY is estimated to be 4029 t at MSY effort of 9317 standard fishing days (SFD) using SchaeferÆs Model. MSY reached 4136 t at MSY effort of 11822 SFD using FoxÆs Model. The current catch of 2444 t at an effort of 7491 SFD indicates over-fishing. If this situation continues, the fishery resources will diminish with time. Precautionary measures should be adopted by the Government to minimize if not totally prevent over-exploitation of the fishery resource in the Bay of Bengal. The Government should enact laws and ensure their enforcement. The present number of large trawlers and boat owners should not be allowed to increase. The trawlers and large boat operators should avoid intrusion into near-shore areas and reduce discards/by-catch problems. Artisanal fishers should abandon destructive fishing gear like estuarine set bag net (ESBN), push nets and current jall that kill small fish. Community-based management should be adopted with initiatives coming from the Government, other international and regional agencies and the stakeholders.Fishery resources, Fishery surveys, Biomass, Population density, Shrimp fisheries, Catch/effort, Trawling, Mathematical models, Coastal fisheries, Marine fisheries, Ecosystems, Socioeconomic aspects, Artisanal fishing, Ecnonomic benefits, ISW, Bangladesh,

Impacts of Thai silver barb (Puntius gonionotus Bleeker) inclusion in the polyculture of carps

The impact of inclusion of Thai silver barb, Puntius gonionotus (Bleeker) in the polyculture with two major Indian carps viz., Labeo rohita, Catla catla and common carp Cyprinus carpio has been studied in seasonal ponds for 115 days. The presence of silver barb decreased the growth of Indian carps while increased that of common carp. A significantly higher (P<0.05) fish yield (1793.65 Kg/ha/yr) was observed in the four species polyculture system containing silver barb when the combined yield of all species was compared

Control of euglenophyte bloom and fish production enhancement using duckweed and lime

Euglenophyte bloom is a common problem in most of the aquaculture ponds in Bangladesh. In the present study we conducted an experiment to control euglenophyte bloom for achieving better fish production using duckweed (Lemna minor) and lime. The experiment was carried out using four treatments, i.e., ponds were supplied with duckweed (T1), lime treatment (T2), both duckweed and lime (T3) and without supply of duckweed and lime (T4). Rohu, catla, mrigal, silver carp and silver barb were stocked and their gut contents were analyzed monthly. The ranges of water quality parameters were analyzed within the productive limit during the experimental period. The mean abundance of euglenophyte was significantly highest in T4 (17.62 ± 1.97 x 10^4 cells/L), followed by T2 (2.96 ± 0.20 x 10^4 cells/L), T1 (1.94 ± 0.35 x 10^4 cells/L) and T3 (1.53 ± 0.42 x 10^4 cells/L). Gut content analysis revealed that considerable amounts of euglenophyte were consumed by silver carp and silver barb, but not preferred by rohu, catla and mrigal. The gross yields of fish were 2133.37, 1967.76, 2816.52 and 1725.62 kg/ha/5 months in T1, T2, T3 and T4 respectively. The highest fish production in T3 and lowest fish production in T4 indicated the use of duckweed and lime is economically sustainable for controlling euglenophytes bloom, maintaining water quality and getting higher fish production

An experimental approach to estimating the value of grain moisture information to farmers in Bangladesh

In the developing world grain storage losses are high and in humid areas inadequate grain drying is often a source of storage problems. Farmers and traders depend on traditional grain moisture estimation methods which are subject to a wide error margin. Grain storage decisions could be improved if farmers and traders had a low cost grain moisture meter that fit their needs. The goal of this study was to determine the desired grain moisture meter functionality and to estimate the value of grain moisture measurement for small holder farmers and for small-scale grain traders, using Bangladesh as a case study. This study was based on interviews with 140 randomly selected Bangladeshi rice farmers in 2016 and 2017, discussions with millers at 30 rice mills and a voucher based moisture meter sales program. It shows that except for rice kept for seed and home consumption, most Bangladeshi farmers sell their rice shortly after harvest to satisfy cash needs and to eliminate storage risks. They say that they would store more rice on-farm if they had better storage methods including cost-effective grain moisture testing. Survey results show that the average farm storage loss was 52 kg or 563 Taka (US$6.78) annually. Using experimental economics methods, farmers were given the opportunity to purchase a probe type grain moisture meter through vouchers with a range of prices. Twenty three of the 140 of the participants (i.e. 16$4.67). No farmer purchased a voucher price over 800 Taka (US$10.00). Those who purchased moisture meters had larger farms and produced more rice than those who did not exercise the voucher. They were also younger on average, have more education and more off farm income than non-purchasers

Feature extraction of human sleep EEG signals using Wavelet Transform and Fourier Transform

Electroencephalogram (EEG) is a complex signal resulting from postsynaptic potentials of cortical pyramidal cells and an important brain state indicator with specific state dependent features. Modern brain research is intimately linked to the feasibility to record the EEG and to its quantitative analysis. EEG spectral analysis is an important method to investigate the hidden properties and hence the brain activities. Spectral analysis of sleep EEG signal provides acute insight into the features of different stages of sleep which can be utilized to differentiate between normal and pathological conditions. This paper describes the process of extracting features of human sleep EEG signals through the use of multi resolution Discrete Wavelet Transform and Fast Fourier Transform. Discrete Wavelet Transform offers representations of the signals in the time-frequency plane giving information regarding the time localization of the spectral components at different stages of sleep in human beings and Fast Fourier Transform provides the spectral information. This paper also discusses the clinical correlation associated with sleep EEG signals in brief

Screening of wheat (Triticum aestivum L.) lines against salinity under field condition

An experiment was undertaken in order to screening wheat genotypes against salinity under field condition with 14 wheat genotypes including 6 check varieties. The genotypes were&nbsp;tested in saline soil where the salinity of the experimental field ranges from 1.5 to 10.3 dS/m during the cropping period. Analysis of variance revealed significant variation among the&nbsp;genotypes for all characters. Phenotypic and Genotypic co-efficient of variation was low for almost all the characters. Phenotypic co-efficient of variation ranged from 8.42 to 23.45 for plant height and yield respectively, while the highest genotypic coefficient of variation (18.90) was observed in yield and lowest (6.83) was found in seed per spike. All of the trait exhibited moderate to high heritability in broad sense (h2b) coupled with a wide range of genetic&nbsp;advance and genetic advance in percentage of mean. Heritability ranged from 37.64`to 91.14 for seed per spike and thousand seed weight respectively. Yield had significant positive&nbsp;correlation with spike length, spikelet per spike, seed per spike, thousand seed weight. On the other hand, yield was found to show a positive relationship with tiller per plant. Tiller per Plant, spikelet per spike, 1000 seed weight were responsible for reduction of yield per plant indirectly. Yield ranged from 1.14 ton/ha to 2.1 ton/ha. The present research work clearly demonstrated that based on field performance considering yield, the genotypes BARI Gom 25 and BARI Gom 26 is best and other some genotypes BAW 1182, BAW 1177 respectively showed their most effective performance on saline soil

Screening of promising biofortified short duration lentil cultivars for conservation agriculture in North-west Bangladesh

In Bangladesh, lentil (Lens culinaris Medikus subsp.culinaris) production was 0.26 million tons from 0.20 million hectares (average yield 1.3 t ha-1) which is 29 % of the total national pulse production (AIS, 2016). Globally, it is cultivated as a rainfed crop on 3.85 million hectares (m ha) with a yield of only 1.1 t ha-1 (Erskine et al., 2011). In rice based cropping patterns, after harvesting of t.aman rice maximum land remains fallow for about 90 days until establishment of the boro rice. Presently, this rice land cannot be used to grow lentil since varieties have 110-115 days duration (AIS, 2017). Promising biofortified short duration (83-90 days) lentil varieties can play an important role to expand its cultivation through establishing lentil by relay sowing into t.aman rice and harvesting before boro rice. The relay cultivation method involves no tillage and residue retention, and establishes the lentil before t.aman rice is harvested. The selection of promising biofortified short duration lentil genotypes under relay cultivation method is therefore important to accommodate in fallow between t.aman and boro rice

Effects of organic manures and chemical fertilizers on the yield of brinjal and soil properties

A field experiment was conducted at the Horticultural Farm of Bangladesh Agricultural University (BAU), Mymensingh during the period from December 2004 to April 2005 to evaluate the effect of manures and fertilizers on the yield of brinjal. There were five treatments consisting of organic, inorganic and combined sources of nutrients, of which the combined treatment (60 % organic +40% inorganic) showed the best performances. The maximum branching (20.1) with the highest number fruits/plant (15.2), fruit length (14.1 cm) and fruit diameter (4.3 cm) were found combined application of manures and fertilizers. The highest yield (45.5 t ha-1) was also obtained from the combined application of organic and inorganic sources of nutrients. Application of mustard oil cake or poultry manure alone gave better performance compared to only chemical fertilizers. The organic matter content and availability of N, P, K and S in soil were increased by organic matter application. On the other hand soil pH was increased with chemical application than organic

Duration of low temperature changes physiological and biochemical attributes of rice seedling

Received: June 2nd, 2022 ; Accepted: August 4th, 2022 ; Published: August 18th, 2022 ; Correspondence: [email protected] low temperature (LT) is detrimental to growth of rice seedling during boro season in Bangladesh. An experiment was conducted in growth chamber during June to October, 2021 using BRRI dhan29 as planting material. The aim of this experiment was to determine the effect of variable duration of LT on growth, physiological and biochemical traits of rice seedling and to determine the age of seedling that can tolerate cold effect. In this experiment 5, 10, 15 and 20 days old seedling (DOS) were exposed to 6 °C for 1, 2, 3 and 4 days. Seedlings were also grown under room temperature (25 °C, RT) which consider as control treatment. Seedlings were grown in plastic trays filled with mixture of soil and cowdung. The experiment was conducted following completely randomized design with 3 replications. Data on shoot length and weight, root length and weight, chlorophyll (Chl), carotenoids, malondialdehyde (MDA) and proline contain were determined after 5 days of temperature sock. The results revealed that the LT was injurious to younger rice seedling when they were exposed to LT for 1 to 2 days. The shoot and root length as well as their dry weight were reduced under low temperature. Further, the Chl and carotenoid content of younger rice seedlings degraded within 2 days of LT exposure. On the contrary, the proline and MDA content of rice seedlings increased to reduce the harmful effect of under LT. It could be concluded that the rice seedlings could tolerate the detrimental effect of LT when they attain at least 15 days

Strip planting decreases nitrogen fertilizer requirements while retention of more residue increases them in a rice - wheat - mungbean sequence on a subtropical floodplain soil

Conservation agriculture (CA) has not been well developed for intensively cultivated (2-3 crops yr-1) rice- based cropping systems which produce large amounts of crop residues annually. Thus, we examined the effects of two crop establishment systems (minimum soil disturbance by strip planting (SP) or conventional tillage (CT)), two residue retention levels (low and high) and five N rates (60, 80, 100, 120 & 140% of the recommended N fertilizer doses (RFD) on nine consecutive crops on an Aeric Haplaquept under rice-wheat- mungbean sequence. Rice yields were comparable between the crop establishment types but system yields were significantly higher with SP in two out of three years compare to CT. Increased residue retention did not significantly influence rice yield but positively influenced system yields. No substantial differences in optimum N rate was estimated between CT and SP for 90% of maximum yield goal (MYG) for all the three years but substantially decreased in SP compared to CT in two out of three years for 95 and 99% of MYG. The N fertilizer requirement was 6-22% higher with high residue retention compared to low residue retention plots for all the three yield goal levels. High residue retention also increased soil organic carbon (SOC) at 0- 6 cm depth in both tillage treatments. In conclusion, introducing CA did not alter the N fertilizer requirements of rice for 90% of MYG but reduced the requirement for 95 and 99% of MYG compared to CT. However, there was evidence that the retained crop residue immobilized N and increased the fertilizer N requirement