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,

Fuzzy modelling using a simplified rule base

Transparency and complexity are two major concerns of fuzzy rule-based systems. To improve accuracy and precision of the outputs, we need to increase the partitioning of the input space. However, this increases the number of rules exponentially, thereby increasing the complexity of the system and decreasing its transparency. The main factor behind these two issues is the conjunctive canonical form of the fuzzy rules. We present a novel method for replacing these rules with their singleton forms, and using aggregation operators to provide the mechanism for combining the crisp outputs

Mixed Ligand Ternary Chelates of Cu(II), Ni(II), Zn(II), Co(II), Mg(II) & Ca(II) with Adenine as a Primary Ligand & 1,10-Phenanthroline, 2,2'-Bipyridyl, Cytosine & Sulphosalicylic Acid as Secondary Ligands

1002-100

Description of two new species of Dorylaimoidea from India

Deux nouvelles espèces de Dorylaimoidea sont décrites et illustrées. #Aporcedorus punctatus n.sp. présente les caractéristiques suivantes : L = 2,4-2,6 mm ; b = 4,8-5,4 ; c = 5-6 ; V = 45-48 ; odontostyle = 15-16 um. Il diffère de #A. filicaudatus Jairajpuri & Ahmad, 1983 par la cuticule pourvue de ponctuations, la plus faible longueur du corps et de l'odontostyle, la vulve située postérieurement et la valeur moindre de c. Le mâle est décrit pour la première fois dans le genre ce qui a conduit à amender la diagnose de ce dernier. #Discolaimus papillatus n. sp. est caractérisé par : L = 1,7-1,9 mm ; b = 4,2-4,6 ; c = 54-60 ; V = 51-57 ; odontostyle = 18-19 um ; spicules = 39 um. Il est proche de #D. similis Thorne, 1939 et de #D. silvicolus$ Sauer & Annells, 1985 dont il diffère essentiellement par les suppléments ventromédians en file continue avec la paire de suppléments adanaux. (Résumé d'auteur

Biology of the penaeid shrimp populations exploited by Estuarine Set Bagnet

Results of analysis of part of the data collected during October, 1989 to December, 1990 are given on the biology and catch assessment studies on the Estuarine Set Bagnet (ESBN) from six sampling stations covering the entire coast line of Bangladesh. Length frequency analysis of seven most commonly occurring penaeid shrimp species have been done with complete ELEFAN software package. The result of exploitation patterns indicate that all penaeids except P. stylifera are being over exploited on their way back to the Sea from the nursery ground. This appeared to be the instances of serious growth over fishing. These species are exploited at a size much lower than the length at first maturity, which strongly suggests a complete withdrawal of the bagnet fishery from the coast of Bangladesh

Allozyme and morphological variation in four hatchery stocks of Thai pangas, Pangasius hypophthalmus in Mymensingh, Bangladesh

Genetic and morphological characters of four hatchery population (Shambhuganj, Brahmaputra, Anudan and Bhai-Bhai) of Thai pangas, Pangasius hypophthalmus in Mymensingh region of Bangladesh was studied using morphological characters and allozyme markers from 29 November 2001 to 29 November 2002. A total of 14 morphometric and 6 meristic characters were verified, among which 3 morphometric (BDA, PELFL and HW) and 2 meristic characters (AFR, CFR) of Anudan hatchery population were found to be significantly higher (p>0.001) than those of the other three hatchery populations. Brahmaputra hatchery population was also significantly higher in two meristic characters (PCFR and CFR). For allozyme electrophoresis nine enzyme markers were used viz.: Esr-1*, G3pdh-2*, Gpi-1*, Gpi-2*, Ldh-1*, Ldh-2*, Mdh-1*, Mdh-2* and Pgm* where three loci (Esr-1*, Gpi-2* and Pgm*) were polymorphic (p>0.95) in Anudan and Brahmaputra hatchery populations. The mean proportion of polymorphic loci per population was higher (33.3%) in Brahmaputra and Anudan hatchery populations. Also the expected heterozygosity levels were 0.149 and 0.177 in Brahmaputra and Anudan hatchery populations, respectively. Based on Nei's (1972) genetic distances, the UPGMA dendrogram grouped the populations into two clusters. The Brahmaputra and Anudan populations are in one group; Shambhuganj, and Bhai-Bhai populations are in the second group. High genetic variation in Thai pangas was observed in the Brahmaputra and Anudan hatchery populations and less variation in the other two hatchery populations

Three new species of the family Actinolaimidae (Nematoda : Dorylaimida) from India

Trois nouvelles espèces appartenant à la famille des Actinolaimidae (Thorne, 1939) Meyl, 1960 sont décrites et illustrées. Deux d'entre elles appartiennent au genre #Neoactinolaimus Thorne, 1967, la troisième au genre #Egtitus Thorne, 1967, #Neoactinolaimus kosambus sp. n., très proche de #N. thornei Chaturvedi & Khera, 1979 et de #N. barbieri Vinciguerra & Heyns, 1984, est caractérisé par : L=1,99-2,11 mm ; b=3,8-4,3 ; c=10,5-12,4 ; odontostyle=25-27 um. spicules=48-51 um. #Neoactinolaimus attenutus sp. n., proche de #N. agilis Thorne, 1967 et #N. thornei, est caractérisé par : L=2,21-2,43 mm ; b=4,4-4,7 ; c=18-21 ; odontostyle=21-24 um. #Egtitus itanagrus sp. n. est caractérisé par : L=1,7-2,6 mm ; b=3,7-4,8 ; c=12-19 ; odontostyle=24-28 um ; spicules=47-60 um ; suppléments ventromédians=8-10. Cette nouvelle espèce est proche de #E. neoelaboratus (Rahman #et al, 1987) Jairajpuri & Ahmad, 1992, #E. zealandicus (clark, 1963) Vinciguerra & Heyns, 1984 et #E. bryophilus$ Thorne, 1967. (Résumé d'auteur

Studies on growth and mortality of Cyprinus carpio (Lin.) in floating ponds

Growth and mortality rate of Cyprinus carpio (Linnaeus) under five different dietary conditions were studied in fifteen floating net cages in ponds of the Bangladesh Agricultural University Campus, Mymensingh. Growth rate was found to vary under different dietary conditions. The feed with mixture of 25% rice bran, 5% wheat bran, 30% linseed oil cake and 40% water hyacinth leaf meal exhibited the highest growth rate. The gain of log of body weight per unit increase of log of total length was significant. Significant survivals of the fishes were found

Friedel’s Salt and Hydrotalcite – Layered Double Hydroxides and the Protection against Chloride Induced Corrosion

This paper discusses some aspects of corrosion protection that fly ash and GGBFS offer to steel reinforcement in concrete. It focuses on the formation of two types of Layered Double Hydroxides (LDH’s). These are Friedel’s salt and Hydrotalcite. While Friedel’s salt is known to form in fly ash blends, the authors support the evidence of hydrotalcite formation in GGBFS blends as a result of the magnesium content in the slag. The paper discusses the corrosion protection performance of GGBFS concrete and compares it to that of fly ash concrete. The paper shows the superior advantage of including GGBFS for corrosion protection. The authors explored the probable reasons for this significant advantage and relate it to the formation of hydrotalcite in GGBFS concretes