PhD Thesis

Comparative Study of Different Types of Sinking and Floating Feeds Formulations for Culture of Pangasius Sutchi

Fri, 01 Jan 2021 00:00:00 GMT

Comparative Study of Different Types of Sinking and Floating Feeds Formulations for Culture of Pangasius Sutchi Mannan, Md.Abdul A study was undertaken to know about the existing farming system of Thai pangas (Pangasius sutchi) and to develop better quality sinking and floating feed from locally available fish feed ingredients. Data on socio-economic condition and farming practices were collected through direct interviews with the randomly selected pangus farmers. Socio-economic conditions of the pangas farmers were found quite developed while they encountered several problems in their farming practices. Study revealed the average production of pangas was 37.50 t/ha along with carps and tilapia was 3.50 t/ha with a FCR value of commercial feed ranging from 1.96 to 2.20. They also revealed that 83% pangas ponds surveyed had CBR within 1.0-2.0 and only 3% had greater than 2.0. Therefore, the study concluded with remarks of major problems in lack of quality feed and their higher market price. As a consequence, the second experiment, locally available nine raw materials and seven types of feed additives were used to formulate two types of sinking and floating diets with two formulas each. Each of the formula also had starter and grower graded feeds. Sinking pellets were 2.0-3.0 mm in diameter and 4-7 mm in length and the floating pellets were 2.0-3.0 mm in diameter. Production cost of these two types of feeds was evaluated whereas the price of sinking starter was BDT 36.17 and 38.32; the growers were BDT 34.50 and 36.39. Furthermore, production cost of floating starter was BDT 44.24 and 46.01; and the grower was BDT 40.95 and 43.39. Protein content ranged from 27.42 to 30.55% in sinking pellet feed and 27.95 to 30.85% in floating pellet feed. Lipid content was ranged from 9.26 to 9.45% in sinking pellet feed and 9.15 to 9.53% in floating feed. In the performance evaluation trial of formulated feeds, third experiments were conducted for a period of four months in Jikorgacha Upazila of Jessore district. Among the formulation of sinking pellet feed, significantly higher gross production was recorded at treatment T2 (40.02±0.76 t/ha) and among the formulation of floating pellet feed treatment T1 (62.89±0.25 t/ha) showed higher gross production. Along with significantly higher feed cost, total cost was also recorded higher at treatment T3 (BDT 2839109.37) for sinking pellet feed fed feeding trial. However, significantly higher gross return from fish sales was obtained from treatment T 3 (BOT 3802303.80), and therefore, BCR was also recorded higher from treatment T2 (1.64). On the other hand, in feeding trial two with floating pellet feed, significantly higher total cost was recorded at treatment T 2 (BDT 2999343 .90) and the gross return from fish sales from treatment T1 (5660775.25). Moreover, significantly higher BCR was obtained from treatment Tr (2.04). Therefore, it is evident that formulation process of floating pellet feed at treatment T 1 provided better economic return compared to its subsequent treatments and sinking pellet feed groups. This Thesis is Submitted to the Department of Fisheries, University of Rajshahi, Rajshahi, Bangladesh for The Degree of Doctor of Philosophy (PhD)

Alternative Livelihood of Hilsa Fisherman with its Marketing System: A Case Study from Chandpur District

Fri, 01 Jan 2021 00:00:00 GMT

Alternative Livelihood of Hilsa Fisherman with its Marketing System: A Case Study from Chandpur District Taslima, Farhana An investigation was carried out to evaluate the income potential and livelihood status of alternative income generating activities of hilsa fisher as well as marketing system of hilsa in Chandpur district (Bangladesh) via interview, focus group discussion and crosscheck interviews with key informants emphasizing on socioeconomic status, overviews of hilsa marketing exercise, marketing channel, marketing constraints and the role of marketing participants for a period of 12 months from January to December 2018. An initial snapshot of survey revealed that the fishers were all male (100%), half were in the middle age group (53%). The overwhelming majority were married (84%) and Muslim (86%) in religion. Most of them were from the nuclear family (67%) and have primary education (67%). A minority of them were illiterate (17%). All of them had access to water via tube-well water (100%). However, a significant minority were using catch latrine (16%) and deprived of electric facilities (29%). Only 3% of the fisherman enjoyed pakka housing facility. A third of the fishers (31 %) were uninformed on modem health facilities and were dependent on the village doctor or kobiraj. Income per annum for a majority of the fishers ranged between BDT 80-150 thousand. We've found that the local fishers had multiple income sources and weren't entirely dependent on their primary occupation for the maintenance of their livelihood. "Fishery ghat" also known as "mach ghat" was the main landing centre of hilsa in Chandpur district from where hilsa was distributed and marketed with grading throughout the country. Though preservation knowledge of some of market participants was alarming, hilsa found to be stored by some aratdar. Majority of intermediaries were self-financed, and a variety of packaging materials were used by market actors. The fishers were marginalized to a large extent both in the credit and product made by the advancing system of money lender, aratdar acted as a commission-based sales agent to sale the catch of fishers at the landing center. Wholesaler invested a huge amount of capital to purchase hilsa for a short period of time, LC paikars exported their entire purchase to overseas market and retailers were the last intermediaries who sold hilsa directly to consumer. Major constrains of hilsa marketing includes infrastructural, long marketing chain, credit facility, effective policy etc. Outcomes of this study will be effective for livelihood development of hilsa fishermen and improvement of hilsa marketing system in Chandpur and other districts of Bangladesh. This Thesis is Submitted to the Department of Fisheries, University of Rajshahi, Rajshahi, Bangladesh for The Degree of Doctor of Philosophy (PhD)

Stock Assessment and Management of hilsa shad tenualosa ilisha in the meghna river of Southeastern Bangladesh considering the emerging Climate change

Fri, 01 Jan 2021 00:00:00 GMT

Stock Assessment and Management of hilsa shad tenualosa ilisha in the meghna river of Southeastern Bangladesh considering the emerging Climate change Nima, Akhery The national fish of Bangladesh, Hilsa shad, Tenualosa ilisha (Hamilton, 1822) is a marine, brackish and freshwaters fish belonging the family Clupeidae (Riede, 2004). It is locally known as ilish or ilsha. The overall objective of this study is to assess the stock of T. ilisha from the Meghna River, Southeastern Bangladesh. A total of 1433 individuals were collected for the period of July 2018 to December 2020 where its body weight (BW) and total length (TL) were measured with 0.01 g and 0.01 cm accuracy for each specimen. The current study was on morphometric relationships through length-weight and length-length relationships, meristic features, condition factors (Fulton’s, KF; allometric, KA; Relative, KR) and form factor of T. ilisha. Physiological status was determined using the equation provided as: ā = W/Lb. If ā was close to the a value (a, LWR parameter) indicated the fish was in ideal condition, whereas ā > a pointed to fatty fish and ā < a to lean fish. The prey-predator status estimated through relative weight. Growth parameters were estimated through the von Bertalanffy equation. Data of length–frequency were analyzed with excel based program and FAO-ICLARM Stock Assessment Tool. The TL ranged from 15.3-57.8 cm while the BW was 37.17–2250 g. The overall KF was 0.7191-1.7098, KA was 0.0014-0.0151 and KR was 0.65-1.66 for T. ilisha in the Meghna River. The maximum KR was found in July while the minimum was in January. The KF was strongly correlated with TL and BW while KR was with BW in the Meghna River. KA has no significant relation neither TL nor BW. The maximum fatty fish was found in the months of December (44%) while the minimum was in October. The highest percentage of lean fish was found in the month February (41%) and the lowest was in September (22%). The WR indicated that the habitat was in stable circumstance for T. ilisha. The TL50 (the length at which 50% of specimens become matured) was calculated by using four models ((i) TL vs. Gonadosomatic index (GSI), Modified gonadosomatic index (MGSI) and Dobriyal index (DI) model, (ii) logistic model (iii) maximum length based model (Lmax) and from the following three models, mean Lm was 26.10 cm. Based on monthly variation in GSI, MGSI and DI value, T. ilisha spawn all over the year with two peaks in October and April in the Meghna River. Macroscopic observations of gonads showed five maturity stages. Based on macroscopic features, Hilsa spawn throughout the year but highest percentages in October. The total fecundity (FT) ranged from 65999 to 1575850. Fecundity was found to be highly correlated with TL and BW. Suitable temperature considered as 25-26◦c for the spawning. Furthermore, mean air temperature is increasing by 0.029 °C y-1, and rainfall is decreasing by 2.96 mm y-1. The growth parameters through von Bertalanffy model of T. ilisha was as Lt = 57.62 (1-exp(-1.13(t- 0.009))). The estimated L∞ = 57.62 cm, K = 1.13 y-1, W∞ = 2024.6 g, t0 = 0.009, tmax = 4.17 year. The overall growth-performance index (Ø') was 3.38. In addition, the age of T. ilisha was estimated as 3.10 years. Fishing mortality (F = 0.97 year-1) rate was lower than natural mortality (M =1.57year-1). Further, estimated exploitation rate (E=0.63) was higher than the maximum permissible exploitation rate (Emax = 0.47). Consequently, overfishing is the greatest pivotal threat for T. ilisha stock in the context of Meghna River, southeastern Bangladesh. The MSY was calculated at 286,327 MT. Scientists and conservationists will be able to establish early management methods and policies based on the findings of this study of T. ilisha to ensure long-term survival in the Meghna River and its adjacent ecosystems.--- This Thesis is Submitted to the Department of Fisheries, University of Rajshahi, Rajshahi, Bangladesh for The Degree of Doctor of Philosophy (PhD)

Water retention capacity build up of fish ponds in North-West region of Bangladesh

Fri, 01 Jan 2021 00:00:00 GMT

Water retention capacity build up of fish ponds in North-West region of Bangladesh Tumpa, Anannya Sen A research work on “Water Retention Capacity build up in North-West region of Bangladesh” was done from August 2015 to March 2019 at Paba Upazilla (Rajshahi University Campus area), Charghat upazilla and Bogura Sadar Upazilla. The main purpose of the research was to increase water retention capacity as well as improve fish production, monitor water quality and growth performance. Water retention capacity and production was improved by three different techniques viz. (i) digging and polythene lining with clay soil, (ii) digging and compost layering and (iii) only digging. Water quality and growth performance was monitored fortnightly with hackit box (DR-2010, USA), net, electric balance and scale. To set up experiment a total of 27 seasonal ponds in three locations (9 at Rajshahi University campus, 9 at Charghat-Bhagha and 9 at Bogra Sadar) were selected. The selected seasonal ponds are being dug at the level of 10 feet. Then all the prepared model ponds are being maintained 8 feet, 7 feet and 6 feet of water level for the treatmentsT1, T2 and T3 respectively in each site. To see the water retention capacity of constructed or re-excavated model ponds, fluctuations in water depths were recorded daily. Five farmer’s practiced ponds from each location were selected as control pond. During 1st year experiment (2017), 80 fingerlings/decimal and in 2nd year (2018) 61 fingerlings/decimal were stocked with similar species composition. The variable for all ponds was water depth of 8, 7 and 6 feet as same as previous year and were considered as Treatment1 (T1), Treatment2 (T2) and Treatment3 (T3) respectively. Feeds were given twice daily with commercial fish feed at 4% total biomass rate. Pond water depth of was recorded everyday using scaled PVC pipe fixed in pond. Growth of fish was monitored fortnightly. During the first experiment in 2017, water depth was found above 3 feet in five seasonal controlled ponds for 6 months in Paba (RU campus) upazila, 3 feet on an average period of 5 months at Charghat Upazilla and Bogura sadar Upazilla. Whereas model ponds lengthened round the year and the highest average water depths were 6.43 feet in T1 at Paba upazilla, 5.47 feet in T1 for 6 to 8 months at Charghat upazilla and in Bogura sadar Upazila 7.00 feet at T1 for the year round. In this experiment the mean water quality parameters both physical and chemical parameters were in the suitable range where there was no significant (p>0.05) difference in temperature, transparency, pH, DO and CO2 among the treatments. The harvesting period was in December. The highest specific growth rate (SGR) 1.33% was found in Paba and Charghat. ------ This Thesis is Submitted to the Department of Fisheries, University of Rajshahi, Rajshahi, Bangladesh for The Degree of Doctor of Philosophy (PhD)