• Title/Summary/Keyword: Tuna Thunnus

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Physical Properties of Biofilm Manufactured from Gelatin of Yellowfin Tuna Thunnus albacares Skin Treated with Acetic Acid (아세트산 처리 황다랑어(Thunnus albacares) 껍질 유래 젤라틴으로 제조한 바이오필름의 물리적 특성)

  • Kim, Ju-Yeon;Kim, Do-Hyeong;Kim, Seon-Bong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.44 no.6
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    • pp.591-596
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    • 2011
  • The present study examined the physical properties of biofilms manufactured from yellowfin tuna Thunnus albacares skin gelatin with the aim of developing a biofilm from fisheries by-products to replace mammalian sources. The physical properties of biofilms from yellowfin tuna gelatin were compared with those of biofilms from porcine gelatin. The yellowfin tuna gelatin biofilm exhibited higher tensile strength (69.08 MPa) and greater elongation (14.32%) than did porcine gelatin biofilm (50.50 MPa and 10.21%, respectively). The ${\Delta}E$ and YI (yellowness index) Huntercolor values of yellowfin tuna gelatin biofilm were three-fold and 15-fold higher, respectively, than values for porcine gelatin biofilm. The opacity value of yellowfin tuna gelatin biofilm was higher than that of porcine gelatin biofilm. The stability against water of yellowfin tuna gelatin biofilm was lower than that of porcine gelatin biofilm at pH 3 to pH 11. Thermogravimetric analysis (TGA) indicated that the thermal stability of the biofilms was about $270^{\circ}C$ for porcine gelatin biofilm and about $250^{\circ}C$ for yellowfin tuna gelatin biofilm.

Feeding habits of the Pacific bluefin tuna, Thunnus orientalis in Korean waters (한국 연근해에 출현하는 태평양참다랑어 Pacific bluefin tuna, Thunnus orientalis의 식성)

  • Jo, Heon Ju;LEE, Sung Il;KIM, Doo Nam;LEE, Mi Kyung
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.55 no.1
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    • pp.20-28
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    • 2019
  • The feeding habits of Pacific bluefin tuna, Thunnus orientalis were analyzed using samples by large purse seine fishery in Korean waters from 2012 to 2017. The number of samples was 1,274 and the fork-length (FL) ranged from 34.6 to 218.0 cm. According to %IRI, the Important main prey items of immature individuals (below 91.4 cm in FL) were Pisces, Cephalopoda and Euphausiacea and those of mature individuals were Cephalopoda and Pisces. T. orientalis showed ontogenetic changes in prey item that Pisces was dominated in size class of 30-89 cm (FL), Cephalopoda in 90-179 cm (FL), and Pisces above 180 cm. As for seasonal changes in prey item, Cephalopoda was dominant in spring and Pisces was dominant in summer, autumn and winter. %F, %N, %W and %IRI cluster analysis divided area into three groups: Group A was dominated by Pisces; Group B was dominated by Cephalopoda, and Group C was dominated by Euphausiacea.

Bioadhesive Characteristics of Biofilm Manufactured from Gelatin Derived from Acetic Acid-treated Skin of the Yellowfin Tuna Thunnus albacares (아세트산처리 황다랑어(Thunnus albacares) 껍질 유래 젤라틴으로 제조한 바이오필름의 생체 접착 특성)

  • Kim, Ju-Yeon;Kim, Do-Hyeong;Moon, Chang-Kwon;Kim, Seon-Bong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.44 no.6
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    • pp.584-590
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    • 2011
  • This study aimed to demonstrate the bioadhesive characteristics of gelatin biofilm to rat skin. The biofilm was manufactured from gelatin extracted from the acetic acid treated-skin of the yellowfin tuna Thunnus albacares. The bioadhesive strength of tuna gelatin biofilm was compared to that of porcine gelatin biofilm. The tuna gelatin biofilm exhibited a higher bioadhesive strength than the porcine gelatin biofilm. Gelatin biofilm was subjected to glutaraldehyde treatment at different concentrations, temperatures and pH in order to improve its bioadhesive strength. Glutaraldehyde treatment improved the bioadhesive strength of gelatin biofilm up to three-fold. The bioadhesive strength of glutaraldehyde treated-biofilm was significantly decreased by application of sodium borohydride.

Feeding habits of the Pacific bluefin tuna, Thunnus orientalis in the southern sea of Korea (한국 남해안에 출현하는 태평양참다랑어 Pacific bluefin tuna, Thunnus orientalis의 식성)

  • YOON, Sang Chul;YOO, Joon Taek;LEE, Sung Il;KIM, Zang Geun;CHOI, Kwang Ho
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.51 no.4
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    • pp.553-560
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    • 2015
  • The feeding habits of the Pacific bluefin tuna, Thunnus orientalis were examined based on the stomach contents of 330 specimens caught by offshore large purse seine fishery in the southern sea of Korea, 2011. The size of Pacific bluefin tuna used in this study ranged from 34.1 to 67.3 cm in fork length (FL). The percentage of empty stomachs was 41.8%. The main prey items were Pisces and Cephalopoda based on percentage IRI (index of relative importance). The main fish preys were Trachurus japonicus, Bregmaceros japonicus, Engraulis japonicus, and Cephalopoda were Todarodes pacificus, Loligo edulis, Watasenia scintillans. T. orientalis showed ontogenetic change in diet composition. Although Pisces dominated the diet of all length classes the portion of Cephalopoda was relatively higher in size between 40 and 50 cm other than length classes. In terms of seasonal variation in feeding habits, Pisces was the main prey group in all seasons, but Cephalopoda was also frequently consumed during spring and autumn based on %IRI.

Species Composition and Catch of Korean Tuna Longline Fisheries in the Indian Ocean from 2010 to 2015 (인도양 해역 우리나라 원양 연승어업의 어획물 종조성과 어획동향(2010-2015년))

  • Ku, Jeong Eun;Lee, Sung Il;Kim, Doo Nam
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.51 no.3
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    • pp.286-297
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    • 2018
  • We analyzed scientific observer data to identify species composition and catch trends of Korean tuna longline fisheries in the Indian Ocean. The data were collected by Korean scientific observers onboard Korean tuna longline fishing vessels in the Indian Ocean from 2010 to 2015. The observers identified 94 species including 5 tuna, 6 billfish, 11 shark, 7 other fish, 5 seabird and 1 sea turtle. Albacore tuna Thunnus alalunga and southern bluefin tuna Thunnus maccoyii were the dominant tuna species, and swordfish Xiphias gladius were the most commonly captured billfish. During the survey periods, 87 seabirds were incidentally bycaught. Black-browed albatross Diomedea melanophris was the dominant seabird species in bycatch, especially in 2010. Cluster analysis showed difference in the species composition of catches between the eastern and western Indian Ocean.

Standardization of CPUE for bigeye(Thunnus obesus) and yellowfin(Thunnus albacares) tunas by the Korean longline fishery in the Indian Ocean (우리나라 다랑어연승어업에 의한 인도양해역 눈다랑어(Thunnus obesus) 및 황다랑어(Thunnus albacares)의 CPUE 표준화)

  • Kwon, You-Jung;An, Doo-Hae;Lee, Jae-Bong;Zhang, Chang-Ik;Moon, Dae-Yeon
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.44 no.3
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    • pp.194-206
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    • 2008
  • This study standardized catch per unit effort(CPUE) of the Korean longline fishery, which has been used to assess the status of stock as an index of abundance, for bigeye and yellowfin tunas in the Indian Ocean. The Generalized Linear Model(GLM) was used to analyze the fishery data, which were catch in number and effort data collected each month from 1971 to 2007 by $5\;{\times}\;5$ degree of latitude and longitude. Explanatory variables for the GLM analysis were year, month, fishing area, number of hooks between floats(HBF), and environment factors. The HBF was divided into three classes while the area was divided into eight subareas. Although sea surface temperature(SST) and southern oscillation index(SOI) were considered as environmental factors, only SST was used to build a model based on statistical significance. Standardized CPUE for yellowfin tuna showed a declining trend, while nominal CPUE for the species showed an increasing trend.

In vivo and In vitro Digestibility of Enzyme-treated Fish Meal for Juvenile Atlantic Bluefin Tuna Thunnus thynnus (효소처리어분에 대한 치어기 대서양 참다랑어(Thunnus thynnus)의 in vivo 및 in vitro 소화율 평가)

  • Shin, Jaehyeong;Ji, Seung-Cheol;Lee, Kyeong-Jun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.53 no.3
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    • pp.423-431
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    • 2020
  • This study was conducted to investigate in vivo and in vitro digestibility in juvenile Atlantic Bluefin tuna Thunnus thynnus. In vivo digestibility was compared between four experimental diets to determine the optimum dietary inclusion level of an enzyme-treated sardine fish meal (EFM) and sardine fish meal (FM). The experimental diets were as follows; EFM75 (75% EFM), EFM60 (60% EFM and 15% FM), FM75 (75% FM) and SL (frozen sand lance) as a raw fish feed. Feces of Bluefin tuna (90.3 g) were collected both by siphoning from a 700 L cage and by dissection in 69 ton concrete rearing tanks. For the siphoning method, protein digestibility was higher in the tuna fed SL diet than that of other groups. The lowest protein digestibility was observed in FM75. For the dissection method, protein digestibility was higher in tuna fed EFM75 diet than that of other groups. The lowest protein digestibility was observed in the EFM60 group. In vitro digestibility was compared in six protein sources to find an alternative source of EFM for the tuna feed. The highest in vitro digestibility was observed in EFM (92%) followed by low temperature FM (72%), meat meal (65%), feather meal (60%), sardine fish meal (57%) and poultry by-product meal (55%).

Effects of Extraction Methods on Histidine-containing Low-molecular Weight Peptides and Pro-oxidants Contents in Tuna Thunnus Extracts (다랑어(Thunnus) 추출물 중의 Histidine 함유 저분자 펩타이드 및 산화촉진물질 함량에 미치는 추출방법의 영향)

  • Kim, Hong-Kil;Song, Ho-Su
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.50 no.6
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    • pp.684-693
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    • 2017
  • We investigated methods for extracting histidine-containing low-molecular-weight (LMW) peptides such as anserine, carnosine and histidine from the edible meat of tuna byproducts. Extracts were treated by several methods including heat treatment ($80^{\circ}C$, 10 min), DOWEX ion exchange (IEC), ultrafiltration (UF), and carboxymethyl (CM)-cellulose column chromatography (IEC+CMC); then the levels of protein, total iron, histidine, carnosine, and anserine were measured. Extracts treated with IEC+CMC using CM-cellulose were analyzed for total iron, protein, histidine, and anserine content, which were $6.27{\pm}0.26mg/mL$, $5.20{\pm}0.21{\mu}g/mL$, 0.80 mg/mL, 0.208 mg/mL, and 4.40 mg/mL, respectively, in yellowfin tuna; and $9.05{\pm}0.82mg/mL$, $4.06{\pm}0.20{\mu}g/mL$, 1.62 mg/mL, 0.012 mg/mL, and 7.28 mg/mL in bigeye tuna. By comparison in IEC-UF treated extracts, protein, total iron, and histidine content decreased by 43%, 73%, and 27% in yellowfin and 0.4%, 54%, and 23% in bigeye tuna, wheres carnosine and anserine content increased by 22% and 17%, respectively. Freeze-dried (FD) extracts exhibited similar trends as non-dried extracts, i.e., dipeptide content increased with purification steps, whereas pro-oxidant (total iron and protein) content decreased. IEC+CMC treated FD extracts had the highest anserine, content, and the greatest reductuion in pro-oxidants.

Stock Assessment of the Southern Bluefin Tuna Thunnus maccoyii Using the MULTIFAN-CL Model (MULTIFAN-CL 모델을 이용한 남방참다랑어 Thunnus maccoyii의 자원 평가)

  • Kwon, You-Jung;Moon, Dae-Yeon;Zhang, Chang-Ik;Koh, Jeong-Rack
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.40 no.6
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    • pp.367-373
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    • 2007
  • We assessed the stock of the southern bluefin tuna (SBT, Thunnus maccoyii) by applying the MULTIFAN-CL model. The model is spatially disaggregated, with the population and fisheries stratified into a number of regions within the overall stock range. Catch, effort, length-frequency, and tagging data from 1965 to 2003 were stratified by three regions and four quarters (Jan-Mar, Apr-Jun, Jul-Sept and Oct-Dec). These data were used to estimate the instantaneous fishing mortality (F), biomass, spawning biomass, recruitment, and so on. The Commission for the Conservation of Southern Bluefin Tuna (CCSBT) used only Japanese data and did not consider migration for the SBT stock assessment. By contrast, we used Japanese, Australian, New Zealand, Taiwanese, and Korean data, and considered migration. As a result, the estimated annual average F of all age classes was 0.073/yr and the F of age class 6-10 was the highest. The results also showed that the biomass and recruitment of SBT had declined significantly after 1965. Compared with the CCSBT results, the estimated spawning biomass in this study was lower and more uncertain. However, we will conduct a sensitivity analysis to get more accurate biological parameters and results. In addition, we need to use the bootstrap resampling method to quantify the uncertainty.