This study investigated species identification and labeling compliance of 48 shrimp products sold in the Korean online markets. Species identification was conducted using the standard DNA barcoding method, using the cytochrome c oxidase subunit I gene. The obtained sequences were compared with those deposited in the NCBI GenBank and BOLD Systems databases. Additionally, phylogenetic analysis was performed to further verify the identified shrimp species. Consequently, 16 shrimp species were identified, including Penaeus vannamei, Pandalus borealis, Palaemon gravieri, Leptochela gracilis, Penaeus monodon, Pleoticus muelleri, Metapenaeopsis dalei, Euphausia pacifica, Lebbeus groenlandicus, Trachypenaeus curvirostris, Argis lar, Metanephrops thomsoni, Metapenaeopsis barbata, Alpheus japonicus, Penaeus chinensis, and Mierspenaeopsis hardwickii. The most prevalent species was Penaeus vannamei, found in 45.8% of the analyzed products. A significant mislabeling rate of 72.9% was found; however, upon excluding generic names such as shrimp, the mislabeling rate reduced to 10.4%. The mislabeling rate was higher in highly-processed products (89.3%) compared with that in minimally-processed products (50%). No correlation was found between the country of origin and mislabeling rate. The results of this study provide crucial data for future monitoring of shrimp products and improving the labeling of shrimp species in Korea.

The annual reproductive cycle of two species, Upogebia major (de Haan 1841) and Austinogebia wuhsienweni (Yu 1931), of the female mud shrimp from the west coast of Korea was investigated using histology. The collected samples were divided into adult and juvenile groups to understand the mature period of age class based on the carapace length (CL). Juvenile Upogebia (CL<25 mm) were mostly inactive gonad with early (62%-100%) and late (10%-38%) development stages during the year, whereas the adult shrimp showed a seasonal pattern of gonad maturation (CL≥25 mm). The early and late developmental stages of oocytes were observed in adult Upogebia from November to March and mature eggs appeared from April to October. In adult Ausitnogebia (CL≥15 mm), fully grown oocytes were consistently observed during the study period, in which the ripe stage was found between January and June. On the other hand, most juvenile Austinogebia (CL<15 mm) maintained an immature state in the gonad. Both species of the mud shrimp reproduced from ovigerous females in the adult population and their egg-bearing period was distinguished from January to April for U. major and from July to September for A. wuhsienweni.

The standards for heavy metal levels in crustaceans are 0.5 mg/kg and 1.0 mg/kg or lower for lead and cadmium, respectively. Further, the contamination levels of arsenic, mercury, methyl mercury, and tin are being continuously investigated, considering their current exposure levels. Shrimps are potentially exposed to heavy metals because they inhabit areas with abundant organic matter, such as sandy or muddy shores, places with a lot of seaweed, and estuaries. This study measured the monetary value of reducing consumer anxiety and increasing consumer confidence if the government prohibits the sale of shrimp species that exceed the threshold for specific heavy metals and of the top shrimp species for which no threshold for heavy metals is specified. We derived consumer willingness-topay (WTP). Combining the estimated WTP with the number of households in the country, the total value of benefits was estimated to be 363.9 billion won. The results of this study will provide an important empirical finding, showing to what extent specific policies regarding heavy metals in seafood can alleviate consumer anxiety and provide psychological reassurance.

Large amounts of waste and wastewater from aquaculture have negatively impacted ecosystems. Among them, shrimp aquaculture wastewater contains large amounts of nitrogen contaminants derived from feed residues in an aerobic environment. This study isolated candidate strains from adult rockworms to treat shrimp aquaculture wastewater (SAW) in an aerobic environment. Among 87 strains isolated, 25 grew well at the same temperature as the shrimp aquaculture with excellent polymer degradation ability (>0.5 cm clear zone). Six isolates (strains AL1, AL4, AL5, AL6, LA10, and PR15) were finally selected after combining strains with excellent polymer degradation ability without antagonism. 16S rRNA sequencing analysis revealed that strains AL1, AL4, AL5, AL6, LA10, and PR15 were closely related to Bacillus paramycoides, Bacillus pumilus, Stenotrophomonas rhizophila, Bacillus paranthracis, Bacillus paranthracis, and Micrococcus luteus, respectively. When these six isolates were applied to SAW, they reached a maximum cell viability of 2.06×105 CFU mL-1. Their chemical oxygen demand (CODCr) and total nitrogen (TN) removal rates for 12 h were 51.0% and 44.6%, respectively, when the CODCr/TN ratio was approximately 10.0. Considering these removal rates achieved in this study under batch conditions, these six isolates could be used for aerobic denitrification. Consequently, these six isolates from rockworms are good candidates that can be applied to the field of aquaculture wastewater treatment.

This study examines the demand system of shrimp imported from top four countries and domestically produced by using AIDS (Almost Ideal Demand System) model. Top four import countries are Vietnam, Ecuador, China, and Malaysia based on the value of imports in 2021. As results of the analysis, the demand system of shrimp turn out to be below. First, the relationship of domestic shrimp and imported shrimp (Ecuadorian and Vietnamese) is identified as complements or substitutes depending on whether the income effect is considered. This result implies that imported shrimp supplements domestic supply against excess demand while homogeneous shrimp products competes with domestic shrimp in fish market. Second, the relationship among imported shrimps turned out to be both substitutes and complements. Especially, the Vietnamese shrimp is complementary with Chinese and Malaysian shrimp, but substitutes of Ecuadorian. It is assumed that adjoining Asian countries shares similar shrimp species and processing system which differentiates from Ecuadorian. Finally, the study included quarter as dummy variable and GDP as instrumental variable of expenditure in the model. The result confirmed that domestic shrimp is highly on demand during the main production season while imported shrimp is mainly demanded during the rest of the season.

Looking at the dietary patterns of women in their 20s and 30s as well as postmenopausal women, the intake of most nutrients was lower than the recommended levels. Shrimp is a low-calorie, high-protein food, and contains abundant minerals, and it is expected to help prevent osteoporosis. In this study, jinmal dasik was prepared by varying the shrimp content at 0, 1, 5, and 7%, and the quality characteristics were measured. Hardness, adhesion, chewiness, and cohesiveness of physical properties increased significantly as the amount added increased (p<0.001). The springiness decreased significantly as the amount of addition increased in the addition group (p<0.001). In the calcium, there was a significant increase as the amount added increased (p<0.001). In the potassium, there was a significant increase as the amount added increased (p=0.049). This study intends to highlight the benefits and possible uses of shrimp.

본 연구는 저염분 상태에서 수온 및 사육밀도와 같은 환경요인이 흰다리새우(Litopenaeus vannamei)의 성장에 미치는 영향을 조사하기 위하여 수행하였다. 연구 결과, 흰다리새우는 저 염분 상태에서 전반적으로 수온이 높을수록 생존율이 높게 나타났고, 사육밀도가 낮을수록 생 존율이 높아졌다. 사료효율에 관한 연구에서는 수온이 높을수록 증체량(WG)이 증가하였고, 사 육밀도가 증가할수록 증체량은 감소하였다. 수온이 높을수록(수온 31℃) 성장 속도가 빨랐다. 또한 사육밀도에 따른 성장도의 평가에서도 사육밀도가 낮은 상태에서 성장 속도가 빨라지는 것을 확인하였다. 본 연구 결과를 흰다리새우의 최적 성장을 위한 적정 사육밀도 및 사육수온 의 결정에 유용하게 적용되리라 사료된다.

In this study, we developed a healthy snack using dried shrimp powder which is rich in calcium to help prevent bone disease. Different types of yanggaeng were prepared with varying ratios of dried shrimp powder; 1%, 3%, 5%, and 7%. Moisture content, color value, texture properties, and mineral concentration were measured. The L, a, and b chromaticity values showed significant differences in the 5% addition group (p<0.001). The texture properties, hardness, and adhesion decreased significantly as the amount of shrimp powder increased (p<0.001), while chewiness and elasticity significantly increased as the amount increased (p<0.001). Calcium and potassium increased significantly as the amount of shrimp powder increased (p<0.001).

Monthly fluctuation in abundance and species composition of fish in coastal waters off Oenaro island, Goheung were investigated using seasonal samples collected by a shrimp beam trawl in 2018. A total of 5,981 fishes were sampled and classified into 48 species, 32 families, and 9 orders. The dominant species was Engraulis japonicus (993 individuals, 16.60%), Amblychaeturichthys hexanema (844 individuals, 14.11%), and Thryssa kammalensis (674 individuals, 11.27%). The highest number of individuals was found in August (958 individuals), while the lowest number of individuals was found in January (136 individuals). The diversity index was the highest in November (H’ = 2.37) and the lowest in January (H’ = 1.77).

Although mud shrimp (Upogebia Major) provides benefits on the tidal flat ecosystem, it is causing the mass mortality of Manila clam (Tapes philippinarum) and large economic loss to the aquaculture farmer due to spreading in the entire coastal clam farm area of the West Sea of Korea. In this study, a mud shrimp blocking box for cultivating clam was tested to prevent the mud shrimp from invading the habitat of the clam. To determine the effect of the blocking box, the growth characteristics of the clams under various culture conditions were investigated. The shell length, total weight, condition index, the presence of mud shrimp in the box, and the soil decay in the box were examined according to whether the clams were raised in the box or in natural state, whether the box is covered with a net or not and the gap size of the box. As a result, no significant differences in shell length, total weight, and condition index were found between the clam grown in the box and the natural state (P>0.05) without any evidence of invading of mud shrimp to the box. In addition, the soil inside the box was in good condition, not decayed. Therefore, using the mud shrimp blocking box, mud shrimp can be prevented from propagating to the habitat of the clam, thereby contributing to the normal production of the clam and thus to restoring the clam farming.

It was turned out by shrimp beam trawl monthly survey from March, 2015 to February, 2016 that different species composition and abundance of the fish assemblages in Sacheon Bay and coastal waters off Namhae, Korea were compared. As a result of monthly measured sea temperature and salinity of Sacheon Bay and coastal waters off Namhae, sea temperature of both areas was changed seasonally; however, differences in sea temperature occurred during certain periods depending on the region. Salinity was generally low in Sacheon Bay affected by fresh water, and both areas was low in summer and high in winter. A total of 73 species representing 37 families were collected in Sacheon Bay. The dominant fish species in terms of numbers and biomass were Liparis tanakae, 23,077 inds./km2, 332.1 kg/km2. A total of 91 fish species representing 49 families were collected in coastal waters off Namhae. The dominant fish species in terms of numbers were Leiognathus nuchalis, 139,683 inds./km2 and biomass were Chelidonichthys spinosus, 1,078.6 kg/km2. Analysis of dendrogram of the clustering showed that Sacheon Bay and coastal waters off Namhae were distinctive featured (global R = 0.691, p = 0.017). And except of summer season (July-October), there was a distinctive feature seasonally (global R = 0.844, p = 0.001). The fish species that appeared in common in both areas, where fish species caught in Sacheon Bay, an important inner bay,were smaller than those caught in coastal waters off Namhae appeared. It presented that Sacheon Bay plays a more important role in spawning and nursery ground for fisheries resource than coastal waters off Namhae, Korea.

안정된 바이오플락 사육수에는 대량의 미생물들이 존재하고 있으며 사육수온이 높아 재사용이 가능할 경우 빠른 수질안정화 및 에너지 절약을 할 수 있다. 바이오플락 사육수 내 부유하고 있는 자가 및 타가 영양세균은 호기성과 혐기성 세균을 모두 포함하고 있어 탄소원을 넣고 산소를 공급하지 않는 혐기성 상태로 만들면 탈질과정이 가능하다. 본 연구에서 바이오플락 탈질수의 특성은 암모니아 (6.9 mg L-1), 아질산 (0.3 mg L-1), 질산농도 (9.2 mg L-1), 높은 pH (8.42), alkalinity (590 mg L-1)였으며 이 탈질수를 첨가한 사육수의 물리적 환경 변화가 어린새우의 생존 및 생리적 특성에 미치는 영향을 조사하였다. 그 결과 탈질수를 100% 사용하여도 생존율의 변화를 보이지 않았으나 혈림프를 포함한 체액 분석결과 탈질수 혼합에 의한 조직손상 및 스트레스 지표인 크레아틴, 혈중 요소성 질소의 증가가 관찰되었고 탈질수 혼합비율이 높을수록 새우 체내 이온 (Na+, K+, Cl-)의 농도가 유의적으로 감소하여 향후 삼투압조절에 영향을 미칠 수 있는 것으로 나타남에 따라 탈질수를 일정비율로 (50% 미만) 혼합하여 사용하는 것이 바람직한 것으로 사료된다.

The species composition and abundance variations of fishery resources in the adjacent marine ranching area, Tongyeong, Korea, were investigated by shrimp trawl, gill net, and longline during the period of July, September, and October in 2016. During the study period, the total catch were 8,522.9 kg with 34 species from the shrimp trawl, 32 species from the gill net, and nine species from the longline. The dominant species were different by gear, which were Hypodytes rubripinnis and Parapercis sexfasciata in the shrimp trawl, Platycephalus indicus and Raja kenojei in the gill net, and Conger myriaster and Scomber Japonicus in the longline. In terms of spatial distribution, Yongchodo showed the highest total catch in number as well as of in weight while Jukdo showed the lowest total catch in number and Bijindo showed the lowest total catch in weight. The amount of demersal fish resources in the survey area estimated as 301 ha, was 99,396 individuals which was converted to be 8,552.9 kg. The amount of demersal fish resources by gear were of trawling area, which area is 127 ha, were 76,251 and 3,489.5 kg, 74 ha in the gill net and longline survey area was 16,213 and 3,457.3 kg, and the other 100 ha area was 6,932 and 1,606.1 kg. In this study, the minimum resources for demersal fish is 61,687 and 4,265.2 kg, and the maximum is 149,439 and 14,197.9 kg.