• 한국수산과학회지
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• 제53권6호
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• pp.942-953
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• 2020

Achieving optimal sustainable yields (i.e., avoiding overfishing and maximizing fishery harvest at the same time) is one of the main objectives in fisheries management. Generally, management reference points (MRPs) such as fishing mortalities (Fmsy, F0.1, Fx%) have been suggested for the purpose. In this study, we intended to suggest MRPs for Korea chub mackerel Scomber japonicus stock, using a stochastic catch-at-age model (SCAA) and evaluate whether the current fishing intensity on the stock is appropriate. We used length frequency and catch-per-unit-effort data on the Korea chub mackerel stock collected from the large purse-seine fishery, and yields landed by all fisheries from years 2000 - 2019. We calculated yield per recruit and spawning potential ratio, and projected spawning stock biomass (SSB) under different fishing mortality, assuming annual recruitments were solely controlled by environmental effects (i.e., steepness of 1.0). Some of our major findings and suggestions were that the overfishing threshold would be F46%; i.e., the fishing mortality in the terminal year, 2019 was 0.257/year, which corresponded to F46%.

• 수산해양기술연구
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• 제58권1호
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• pp.32-38
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• 2022

In this study, Target strength for multi-frequency (38 kHz, 70 kHz, 120 kHz and 200 kHz) of chub mackerel (Scomber japonicus) was estimated using by the KRM model. The body shape of the Chub mackerel was described by an X-ray system and the body length of 20 individuals ranged from 16 cm to 28 cm. The swimbladder tilt angle ranged between -8 and -14°, the maximum TS value according to the swimming angle of chub mackerel was -33.0 dB at -11°. The averaged TScm according to fork length was -66.02 dB at 38 kHz, -66.50 dB at 70 kHz, -66.00 dB at 120 kHz and -67.35 dB at 200kHz, respectively.

• 한국수산과학회지
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• 제39권1호
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• pp.35-41
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• 2006

The feeding habits of Spanish mackerel (Scomberomorus niphonius) were studied based on the examination of stomach contents of 445 specimens collected from January to December 2004, in the Southern Sea of Korea. The size of Spanish mackerel ranged from 26.1 to 105.4 cm in fork length (FL). Spanish mackerel was a piscivorous fish which mainly consumed teleost fishes such as chub mackerel (Scomber japonicus) and anchovy (Engraulis japonicus). Its diet also included small quantities of shrimps, stomatopods, cephalopods, crabs, polychaetes, amphipods, cumaceans and copepods. Smaller individuals (<60 cm FL) consumed small fishes such as Engraulis japonicus and crustaceans. The portion of these prey items decreased with increasing fish size, and this decrease was paralleled with increased consumption of lager fishes such as Scomber japonicus and Cololabis saira. The prey size increased with the increase of fish size.

• 한국수산과학회지
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• 제48권5호
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• pp.760-767
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• 2015

First annulus formation and age determination of otoliths were examined for chub mackerel Scomber japonicus collected in Korean waters over the one year from January to December in 2009. Translucent zone was regarded as an annual mark. Age interpretation criteria was based on the data of the number of translucent zone, capture date, and edge type of the otolith, assuming the nominal birthday to be 1 January. Monthly changes in mean marginal index indicated that translucent zone was formed once a year, mainly in June. The otolith of 0-ring group was detected comparing the progression by month of the smaller fish length, appearing to be a single first opaque zone. The average distance from the core to the first translucent zone was ~1.77 mm, provided as supplementary information to increase ageing accuracy. The ageing criteria for chub mackerel was made to determine correct year-class with the purpose of effective stock assessment. This method using nominal birthdate and edge type analysis could estimate age of fish closer to the true age than purely counting the number of translucent zone on a whole otolith.

• Fisheries and Aquatic Sciences
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• 제14권4호
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• pp.257-265
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• 2011

The effects of cooking method (grilling, frying, steaming, and microwaving) on the proximate composition and protein quality of chub mackerel Scomber japonicus treated with 2, 6, and 10% sodium chloride (NaCl) brine were investigated. Moisture content decreased in all cooked samples from 60.22% in the raw sample to 48.7% in the fried samples. Brine (10% NaCl) treatment recorded the highest moisture loss. All cooked samples showed a decrease in fat content, except fried samples. Protein content increased in all cooked samples, from 47.21% in the raw sample to 63.87% in the grilled sample. Brine treatment resulted in the highest degree of fat oxidation (thiobarbituric acid-reactive substances), which was highest in the fried samples and lowest in the microwaved samples. The trypsin inhibitor (TI) concentration was highest in the microwaved samples and lowest in the fried samples. In all samples, 6% salt treatment caused the lowest TI level and the highest in vitro protein digestibility. In vitro digestibility increased from 79.4% in the raw sample to 86.43% in the fried samples. The total essential amino acids of all cooked samples increased. Results suggested that grilling and steaming had beneficial effects on the protein quality of chub mackerel.

• 한국수산과학회지
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• 제46권6호
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• pp.739-745
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• 2013

This study was conducted to evaluate the qualities of mackerel Scomber japonicus sausage prepared with Theragra chalcogramma surimi (TS, A grade), Nemipterus virgatus surimi (NS, A grade) (0, 5, 7, 10%), and 7% NS with starch (0, 1, 2, 3%). The whiteness of the mackerel sausage was significantly increased by adding TS and NS, but that of the NS with starch groups was decreased compared with the control. The hardness increased significantly with the addition of TS, whereas the NS and NS with starch groups showed no considerable differences compared with the control. The gel strength was not significantly different among the mackerel sausage additive groups. In the sensory evaluation, the mackerel sausages containing 5% TS, 7% NS, and 7% NS with 2% starch had the highest overall preference. In conclusion, these results suggest that 5% TS, 7% NS, and 7% NS with 2% starch improve the quality, texture and sensory properties of mackerel sausage.

• 한국수산과학회지
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• 제46권6호
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• pp.708-716
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• 2013

Changes in the proximate composition, lipid classes, and fatty acids were studied in chub mackerel Scomber japonicus and Japanese jack mackerel Trachurus japonicus muscles cooked using a frying pan, oven, and microwave oven. The moisture content was high in the raw samples (chub mackerel 65.5%, Japanese jack mackerel 60.5%) and decreased with cooking, especially in the frying pan method (chub mackerel 49.2%, Japanese jack mackerel 49.8%). In contrast, the protein, lipid and ash contents increased significantly with cooking in chub mackerel muscle (P<0.05). However, the lipid content of Japanese jack mackerel muscle showed no significant difference between the samples using the three cooking methods and the raw sample. The dripped lipid contents from the cooked muscles showed the highest levels in the frying pan samples and the lowest levels in the microwave oven samples. The percentage of non-polar lipid (NL) in the total lipid content was over 95% in the muscle lipids (10.43-21.86 g/100 g sample). Prominent fatty acids were 16:0, 18:1n-9, 22:6n-3 (docosahexaenoic acid, DHA), 16:1n-7 and 20:5n-3 (eicosapentaenoic acid, EPA) in both fish muscles and dripped lipids. There was no change in the EPA level in any of the fish muscles, by any cooking method. The percentage of DHA in the muscle of chub mackerel showed the lowest level in the frying pan sample and the highest level in the microwave oven and raw samples, and an intermediate level in the oven sample. However, the percentage of DHA in the Japanese jack mackerel muscle was not significantly different between the various cooking methods. From these results, the microwave oven and oven cooking methods showed relatively low levels of dripped lipid content and loss of n-3 PUFA compared with the frying pan cooking method.

• 한국수산과학회지
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• 제48권2호
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• pp.221-232
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• 2015

Broadband echoes measured in live chub mackerel Scomber japonicus, goldeye rockfish Sebastes thompsoni, and fat greenling Hexagrammos otakii with different morphologies and internal characteristics were analyzed in time and frequency domains to understand the species-specific echo feature characteristics for classifying fish species. The mean echo image for each time-frequency representation dataset obtained as a function of orientation angle was extracted to mitigate the effect of fish orientation on acoustic scattering. The joint time-frequency content of the broadband echo signals was obtained using the smoothed pseudo-Wigner-Ville distribution (SPWVD). The SPWVDs were analyzed for each echo signature of the three fish species. The results show that the time-frequency analysis provided species-specific echo structure patterns and metrics of the broadband acoustic signals to facilitate fish species classification.

• 한국수산과학회지
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• 제51권6호
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• pp.623-631
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• 2018

The present study investigated the food component characteristics of a bone-softened mackerel Scomber japonicus product (FC-M). The proximate composition of the FC-M was 57.4% moisture, 25.2% crude protein, 14.1% crude lipid, and 2.7% ash. The energy in the FC-M was 241.5 kcal/100 g, which corresponds to 8.9-16.1% of the daily energy intake recommended for Koreans ${\geq}6$ years of age. Regardless of type of taste, there were no significant differences in taste intensity when the FC-M was compared to a control (canned mackerel) but the odor intensity was significantly higher. Although there were no significant differences in hardness, the Hunter color values of redness and yellowness were significantly lower than those of the control. The sensory score for the FC-M was significantly superior to that of the control. The total amino acid content in the FC-M was 24.12 g/100 g and the major amino acids were aspartic acid, glutamic acid, leucine, and histidine. The major fatty acids in the FC-M were 16:0, 18:1n-9, 20:5n-3, and 22:6n-3 and the FC-M was a good source of minerals.

• Food Science and Biotechnology
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• 제16권1호
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• pp.67-70
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• 2007

Mackerel (Scomber japonicus) often causes severe allergic reactions in sensitive people. Food containing undeclared mackerel may pose a risk to such people. The major allergenic protein in fish such as mackerel, codfish, and Alaska pollack has been found to be parvalbumin. In this study, we developed a polymerase chain reaction (PCR) method to detect mackerel DNA using primers corresponding to the parvalbumin gene. We cloned and sequenced 1.5 kb of parvalbumin gene by PCR using mackerel genomic DNA as a template. Nucleotide sequence analysis of genomic parvalbumin gene, composed of 4 exons and 3 introns, allowed the selection of two pairs of oligonucleotide primers specific for mackerel. These primers successfully enabled PCR amplification of specific regions of genomic parvalbumin DNA from mackerel, but no amplification from 8 other fish samples, surimi, and 6 boiled fish pastes. The sensitivity of this method was sufficient to detect 5 ng of purified mackerel DNA mixed with 50 ng of surimi DNA. This rapid and specific method for the detection of allergenic mackerel would be beneficial in reducing food allergy caused by the ingestion of hidden allergen in processed food.