Status and prospects of mackerel and tuna fishery in Bangladesh

Present status and future prospects of mackerel and tuna fisheries in Bangladesh were assessed during July 2003-June 2004. The work concentrated on the fishing gears, length of fishes, total landings and market price of the catch and highlighted the prospects of the fishery in Bangladesh. Four commercially important species of mackerels and tuna viz. Scomberomorus guttatus, Scomberomorus commerson, Rastrelliger kanagurta, and Euthynnus affinis were included in the study. About 95% of mackerels and tuna were caught by drift gill nets and the rest were caught by long lines (4%) and marine set-bag-net (1%). Average monthly total landing of mackerels and tunas was about 264 t, of which 147 t landed in Cox's Bazar and 117 t in Chittagong sites. Total catches of the four species in Cox's Bazar and Chittagong sites were found to be 956 and 762 t, respectively. The poor landing was observed during January-February and the peak landing was in November and July. Gross market value of the annual landing of mackerels and tunas (1,718 t) was found to be 1,392 latch taka. Nevertheless, the mackerel and tuna fisheries in Bangladesh are increasingly contributing to the marine fish production of the country and have very good potential for further expansion for both domestic and export market.

Identification and measurement of fatty acids, amino acids in roe of tuna fish (Thunnus tonggol) and its TVB and peroxide value during cold storage

The first aim of this research was to identify fatty acids, amino acids composition of Thunnus tonggol roe and their changes during cold storage (-18'C). The second aim was to determine the changes of moisture, protein, fat and ash contents of the roe during one year cold storage (-18'C). 60 samples of longtail tuna (Thunnus tonggol) ovaries were randomly collected form Bandar-e-Abbas landings. The samples were frozen at-30'C and kept in cold store at -18'C for one year. According to a time table, the samples were examined for identification of fatty acids, amino acids, moisture, protein, fat, ash, peroxide and T.V.N. and their changes were evaluated during this time. The results showed that 26 fatty acids were identified. The unsaturated fatty acids (UFA) and saturated fatty acids (SFA) were 62.33 and 37.6%, respectively, in fresh roe. So that, DHA (C22:6) and oleic acid (C18:1) had high amounts (24.79 and 21.88%) among the UFA and palmitic acid (C16:0) was the most content (22.75%) among the SFA. The PUFA/SFA was 0.91. Also, 17 amino acids were identified that essential amino acids (EAA) and nonessential amino acids (NE) were 10478 and 7562 mg/100g, respectively, and E/NE was 1.38. Among the EAA and NE, lysine (2110mg/100g) and aspartic acid (1924 mg/100g) were the most contents. Also, results showed that moisture, ash, protein and fat contents were 72.74, 1.8, 19.88 and 4.53%, respectively, in fresh roe. The effects of freezing and cold storage on the roes showed that UFA and SFA contents have reached to 49.83 and 48.07%, respectively, at the end of cold storage. It indicated that these compounds change to each other during frozen storage. Also, n-3 and n-6 series of fatty acids were 32.75 and 1.61% in fresh roe. But their contents decreased to 22.96 and 1.25% at the end of period. Among the fatty acids, 22:6 and C16:0 had the most changes. The changes of fatty acids were significantly at 95% level except for C15:1, C18:3(n-3) and C20:4(n-6). All of the amino acids decreased in frozen storage and their changes were significantly (P<0.05). EAA was 7818 mg/100g and E/NE was 1.27 at the end of storage period. Among the amino acids, leucine and lysine had the most changes. Moisture, ash, protein and fat contents were 70.13, 1.82, 19.4 and 6.51%, respectively, at the end of storage period. The peroxide value and T.V.N. increased during storage. So that, their contents have reached to 5.86 mg/kg and 26.37 mg/100 g, respectively, at the end of frozen storage. The best shelf life of Thunnus tonggol roe was 6 or 7 months, because of lipid oxidation and increasing of peroxide.

Population dynamics and management of yellowfin tuna (Thunnus albacares) of the Oman Sea

The Yellowfin tuna was caught more than all other species in the southern waters of Iran (24000 tons in 1998). In order to come up with the responsible fishing pattern, there was a need to identify some of the biological characteristics and population dynamic parameters. This thesis was the first which covered the whole Yellowfin tuna distribution in the Oman Sea, included the fishing grounds of Berris, Ramin, Chabahar, Pozm and Jask. The data during 1998-99 from different fishing grounds were polled. Based on the exponential relationship between length and weight in the size range 38-173 Cm, the relationship (W=aL^ b) was calculated as W=0.000012L ^ 3.0831). The mean fork length,head length,girth and weight were calculated respectively 84.15 Cm, 23 Cm, 53 Cm, and 11828 g. Length infinity was estimated 189 Cm with growth parameters of 0.42 per year. Growth performance index was 4.18 which was in agreement with the findngs of the other studies in the Indian and Pacific Oceans. The mortality parameters and exploitation rate were estimated as below: Z = 1.75-1.85 M=0.6 F=1.25 E=0.68 Occurence of empty stomach was high (60%) in the speciemens obtained from the Oman Sea. Purpleback flying squid (Sthenoteuthis oualaniensis) was the most dominant prey species observed in the study (57% in females and 60% in males), occurrence of teleost fishes were found to be the second (38% in males and 42% in females). Crabs also were identified in the specimens(1-2%). The study on sex ratio indicated that males were predominant at all sizes above 120 Cm fork length. 50.82% of specimens were males and 49.18% females. The monthly gonadosomatic index was deriven higher values during January to June which could be indicated as spawning period.

Rare occurrence of a bigeye tuna Thunnus obesus in British waters, with notes on other occurrences of sub-tropical tunas

A freshly dead bigeye tuna Thunnus obesus was washed ashore near Burry Port, Wales (51 degrees 40' N; 4 degrees 15' W) in August, 2006. This is only the third occasion that the species has been observed in British waters, and is the largest and most northerly recorded specimen.

Does variability in temperature and chlorophyll concentration influence Wahoo and Yellowfin tuna landings in Bermuda (1990-2006)?

Dissertação de mest., Biologia Marinha, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2009

A value chain analysis of tuna industry in Ghana

Every can of tuna purchased by the consumer has taken a long journey before reaching the supermarket shelves. For each can bought there is a lengthy process from sea to shelf. A large proportion of the tuna cans purchased in the European Union come all the way from West Africa; a developing region with a high dependency on fisheries. Amidst an ever-increasing demand for tuna products the global tuna fisheries are set to continue expanding, apparently one of the last natural resource based industries fit to do so in West Africa. Tuna is the biggest fisheries export and dominates the fisheries sector in Ghana, a country situated in West Africa. This thesis aims to understand how this globally important industrial fisheries functions in terms of procedures, practices, Governance and finance. Socioeconomic influences, in the setting of a developing country, were also examined. For these purposes a Value Chain Analysis was employed. A Value Chain Analysis is a tool commonly used to understand how different companies and organizations participate in a domestic policy environment, which directs conclusion in the global economy. This analysis has the potential to allow researchers to fully understand a commodity chain and hence identify realistic opportunities for consequential improvements. Interviews and questionnaires were employed in-field Ghana along with secondary data collection techniques. It was found that the fisheries functions at the production level under influences from large multinational companies and tends to operate with a certain degree of lawlessness. Governance over the value chain is well defined, however implementation is poor or non-existent. The processors, whom are also dominated by multinationals, exert some control over the producers and their sales, however the high value links which are highlighted occur at the retail stage. Socioeconomic dynamics acting in the chain included the lack of communication between the public and private sector, power imbalances amongst players at production, the role of local businesswomen as actors in the chain and the general characteristics of the workers in the industry. Value addition and upgrading are needed the most in Governance over the chain, especially within Monitoring, Control and Surveillance. The results of the study provide a wealth of material about the components of a cost-heavy fishing industry in a developing country; an industry on which many eyes have recently turned due to illegal fishing activities. It highlights clearly where funding and future focus are needed. This value chain can be used as a guide for those that need to comprehend the financial complexities and real life dynamics of the Ghanaian tuna fishing industry today.

Assessing the atmospheric oscillations effects on the biology of the bullet tuna (Auxis rochei) and its possible linkage with global warming

Dissertação de mestrado, Biologia Marinha, Faculdade de Ciências e Tecnologia, Universidade do Algarve; Instituto Español de Oceanografia; 2015

Estabilidad de componentes bioactivos de tuna roja (opuntia ficus indica) en la encapsulación y desarrollo de productos extrudidos.

Tesis (Doctor en Ciencias con acentuación en Alimentos) UANL, 2014.

Thermal Processing of Smoked Yellowfin Tuna (Thunnus albacares) in Flexible Pouches

This study is the first of its kind in India, where in smoked and thermal processed products have been developed using locally available wood as the source of wood smoke and flavoring and a shelf life of one year has been achieved. Retortable pouches of three layers, both imported and indigenous were found suitable to store thermal processed products. Heat penetration rate is quicker in retort pouches due to their thin profile in comparison to cans and hence the total process time is lesser. The nutritional and sensory attributes of the pouch products are better retained during processing. Hence these products are more acceptable than canned products. lndian vegetarian food products and fish curry products are available in the ready to eat form in the markets. Smoked and thermal processed products have not gained an entry to the market and hence this study will pave an opening for such products. Currently trade in tuna products from India is meager compared to the global trade. ln India proper utilization of tuna resources is yet to be achieved due to the lack of infrastructure for handling and knowledge of value addition. The raw material cost is also less due to the poor quality of the fish when landed. Hence, the availability of such products will help in the trade of tuna products, improving the quality of raw material landing and ultimately realizing a better value to the fishermen and processors.

Studies on tuna livebait fishes of Lakshadweep

Extensive investigations on the distribution and biology of skipjack tuna are available but less is known of the bait fishes on which this fishery depends and what is known is inadequate, fragmentary and of cursory nature. The information available on tuna livebait fishes of Lakshadweep are mainly cofined to short term surverys aimed at estimating theiravailability and abundance. Reports on the biology of a few species from Minicoy are also present in the literature. This study was, therefore, prompted by a paucity of information on 1) the livebits of Minicoy, 2) livebait fishery of the northern islands and 3) knowledge of livebait ecology

“Effect of spice oleoresins in microbial decontamination and their potential application in quality stabilization of Tuna (Euthynnus affinis) during storage”

Unprocessed seafood harbor high number of bacteria, hence are more prone to spoilage. In this circumstance, the use of spice in fish for reduction of microorganism can play an important role in seafood processing. Many essential oils from herbs and spices are used widely in the food, health and personal care industries and are classified as GRAS (Generally regarded as safe) substances or are permitted food additives. A large number of these compounds have been the subject of extensive toxicological scrutiny. However, their principal function is to impart desirable flavours and aromas and not necessarily to act as antimicrobial agents. Given the high flavour and aroma impact to plant essential oils, the future for using these compound as food preservatives lies in the careful selection and evaluation of their efficacy at low concentrations but in combination with other chemical preservatives or preservation processes. For this reason they are worth of study alone or in combination with processing methods in order to establish if they could extend the shelf-life of foods. In this study, the effect of the spices, clove, turmeric, cardamom, oregano, rosemary and garlic in controlling the spoilage and pathogenic bacteria is investigated. Their effect on biogenic amine formation in tuna especially, histamine, as a result of bacterial control is also studied in detail. The contribution of spice oleoresin in the sensory and textural parameters is investigated using textural profile analysis and sensory panel. Finally, the potential of spices in quality stabilization and in increasing the shelf–life of tuna during frozen storage is analysed

Universidad y comunidades huaches de Huanacache: un aporte para el desarrollo local endógeno a partir del cultivo de la tuna

Descripció d'un projecte de la Universidad Nacional de Cuyo sobre el cultiu de la figuera de moro com a entre la comunitat Huarpe de Guanacache, Argentina

Production and quality assessment of a smoked tuna (Euthynnus affinis) product

The sensory, instrumental, and chemical profile of a smoked tuna product comparable and competitive to smoked turkey and pork was studied, based on four experimental factors. Despite their different brining times, all brined, sliced portions of tuna were assessed by panelists as quite acceptable products in terms of firmness, juiciness, color, and saltiness. Protein denaturation seemed to be affected by the brining time. Lipid oxidation seemed quite extensive; the ratio of C22:6n-3/C16:0 was decreased at 15% and 20%. Histamine content was between 3.7 mg/ 100 g and 7.5 mg/100 g. After 3 mo in refrigeration, the aerobic bacteria was 19.10^5 to 250.10^6 in contrast to the unprocessed samples at 28.10^5.