지속가능한 뱀장어 양식업을 위한 자원관리 개선방안 - 한국과 일본을 중심으로 -

백은영 한국도서(섬)학회 2020 한국도서연구 Vol.32 No.3

뱀장어는 내수면 양식업의 대표적인 수산물이자 어류 양식에 있어서도 상당한 비중을 차지하고 있다. 그러나 뱀장어를 양식하기 위해서는 치어인 실뱀장어의 인공종자 대량 생산기술이 확립되지 않아 반드시 자연에서 실뱀장어를 채포해야만 한다. 이에 뱀장어 자원관리에 대한 필요성이 한층 대두되고 있다. 전 세계 뱀장어 생산량은 2000년대 20만 톤에서 2018년에 27만 톤까지 증가해 뱀장어 수요가 크게 늘고 있다. 이 중 양식산은 전체의 97.1%를 차지하나, 양식산 뱀장어 생산량 증가는 자연산 자원감소의 요인으로 지적된다. 이는 양식산과 자연산 뱀장어 모두를 감소시키는 결과로 이를 보호하고 자원관리를 하고자 하는 국제사회의 논의가 활발히 진행되고 있다. 2009년 유럽산 뱀장어가 CITES 부속서에 등재된 후 2013년부터 전면적으로 국제거래가 금지되었다. 한편 2014년 6월과 11월에는 극동산과 북미산 뱀장어가 IUCN의 적색목록에 게재되면서 멸종위기종으로 관리되고 있어 안심할 수 있는 단계가 아니다. 만약 극동산 뱀장어가 유럽산과 같이 CITES 부속서에 게재될 경우 뱀장어 양식산업의 존립을 담보할 수 없다. 이에 2014년을 기점으로 극동산 뱀장어를 양식하는 우리나라를 비롯한 일본, 중국, 대만에서는 뱀장어의 자원관리에 관심을 갖게 되었으며, 4개국의 공동성명 발표 이후 각 국의 실뱀장어 입식량 상한제 도입 등 많은 변화가 있었다. 특히 뱀장어 주요 소비국인 한국과 일본에서 도입한 뱀장어 자원관리 제도는 극명한 차이를 보이고 있다. 이에 본고에서는 극동산 뱀장어가 CITES 부속서에 게재될 경우 큰 피해가 예상되는 한국과 일본의 뱀장어 자원관리 정책을 비교해 보고자 한다. 먼저 한국의 뱀장어 자원관리 정책은 2014년 공동성명 발표에서 제시한 실뱀장어 입식량 제한, 2020년 8월 28일 시행된 「양식산업 발전법」에 의한 뱀장어 양식업 허가제, 실뱀장어 채포허가, 「내수면 어업법」에 의한 산란기 친어 어획 금지, 뱀장어 방류 등이 있다. 그러나 우리나라 정책들 대부분은 규정이 명목에 불과해 실질적으로 규제가 제대로 시행되고 있다고 보기 어렵다. 반면, 일본은 우리나라와 같이 규제 대부분이 존재하며, 여기에 뱀장어 서식처 조성과 각 부처 간의 자원관리까지 보다 구체적이고 실질적인 규제가 이루어지고 있다. 또 다른 특징으로는 규제를 위반할 경우 대부분 징벌이 징수된다는 점과 매년 허가를 갱신해야 하며, 실뱀장어 입식량과 채포량 보고 의무화 등으로 우리나라보다 뱀장어 양식이 한층 어렵다는 것이다. 그럼에도 불구하고 일본에서 뱀장어 양식을 하고자 하는 궁극적인 목적은 중요한 식량자원인 동시에 식자재로써 뱀장어 식문화가 갖는 가치 때문일 것이다. 앞으로 지속가능한 뱀장어 양식을 위해서는 자원관리가 절대적으로 필요하다. 이를 위한 방안으로 자료 표준화, 자원관리 투명성 제고, 국제적인 공조와 협력, 그리고 실뱀장어의 인공종자 산업화를 위한 지속적인 R&D 연구 등을 제안하였다. Eels are a major aquaculture fish in Korea and Japan, and their fisheries are also highly positioned. However, for eel farm, it is possible only by natural capture in glass eel where the mass production technology of artificial glass eel is not established. As a result, the interest and need for eel resource management is higher than ever. Meanwhile, in the 2000s, with the increased demand for eels, global eel production steadily increased to 270,000 tonnes in 2018. Of these, the percentage of aquaculture is significantly higher at 97.1% of the total, but the increase in aquaculture production is eventually pointed out as a resource reduction factor for natural eels. In other words, the international community's interest in protecting and managing resources as a result of reducing both aquaculture and natural eels is actively being conducted. In 2009, Anguilla anguilla were banned from international trade in 2013 after the CITES annex was listed. Meanwhile, in June and November 2014, Anguilla japonica and Anguilla rostrata were listed on the IUCN's red list, which is not a safe step because it is administered as an endangered species. If Anguilla japonica is published in the CITES annex, such as the Anguilla anguilla, the eel farming industry cannot be guaranteed. In this section, we would like to compare the eel resource management policy of Korea and Japan, which is expected to cause significant damage if the eel is published in the CITES annex, and propose an improvement plan. First, Korea's eel resource management system was limited to the eel fish restriction stipulated in a joint statement in 2014, eel farming permit sanctioned by the “Aquaculture Industry Development Act” implemented on August 28, 2020, permit for the capture of eels, prohibition of fishing for eels, and eel ingestion by the "Inland Fishery Act". However, it is difficult to believe that most of our policies are in effect properly enforced because the regulations are only nominal. On the other hand, Japan, like korea, the most of the regulations exist, and here more specific and practical management is made to the creation of eel and resource management between each ministry. Another feature is that retribution is granted in case of violation of regulations and requires the renewal of license every year, eel farming is more difficult than in Korea. In the future, sustainable eel production requires absolute resource management. The proposal sought to standardize data, increase transparency in resource management, cooperate with international cooperation, and continue R&D research for the industrialization of artificial glass eel.

생선회로서 붕장어 (Conger myriaster) 및 갯장어 (Muraenesox cinereus)의 식품성분 비교

김진수,오광수,이정석,KIM Jin-Soo,OH Kwang-Soo,LEE Jung-Suck 한국수산과학회 2001 한국수산과학회지 Vol.34 No.6

In Korea, the conger eel, Conger myriaster and sea eel, Muraenesox cinereus have been eaten as a sliced raw ash meat for a long time. This study was carried out to compare the food component and sensory differences of the conger eel and sea eel as a sliced raw fish meat. The yield and ash content of conger eel were slightly higher than those of sea eel, and no significant differences in moisture, crude protein and crude lipid. The major fatty acids of conger eel were 16:0 ($19.9\%$), 18 : 1n-9 ($36.1\%$) and 22: 6n-3 ($8.3\%$), while those of sea eel were 16:0 ($24.0\%$), 16: 1n-7 ($12.1\%$) and 18:1n-9 ($21.9\%$), The contents of (n-3)-fatty acids were low in all of the two samples. The contents of total amino acid in the conger eel and sea eel were 19,147.2 mg/100 g and 18,527.1 mg/100 g, respectively. The major amino acids of two samples were aspartic acid, glutamic acid and lysine. The chemical score in protein of conger eel was higher about $6\%$ than that of sea eel, and the Ca and P contents of conger eel were also higher than those of sea eel. Although the nutritional value of conger eel as a sliced raw fish meat was generally higher than that of sea eel, the sensory scores in taste and texture of conger eel were lower than those of sea eel.

실험 어도에서 실뱀장어의 소상 행동

황선도,이태원,황학빈,최일수,황선재 한국어류학회 2010 韓國魚類學會誌 Vol.21 No.4

Upstream behavior of glass eels was examined in an experimental eel-ladder at a laboratory of the National Fisheries Research and Development Institute from March to May in 2008. The study was made under various environmental factors and conditions affecting the upstream migration of glass eels in order to design a functional ladder that would allow the passage of glass eels. The experimental eel-ladder consisted of an upper freshwater chamber and a lower sea water chamber;glass eels in sea water can move up to the upper freshwater chamber through the slope (eel-ladder)between them. The optimal condition of the eel-ladder was estimated by comparing the number of glass eels that moved upstream depending on various conditions. Since the glass eels actively moved up the slope to river water rather than to reservoir water or tap water, the experiment was realized using river water. A significantly higher number of glass eels moved up during the spring tide than during the neap tide, and during night than during the day. Upstream movement was significantly higher during high tide than during low tide. Glass eels effectively moved up through a slope of less than 30℃and water-flow velocity lower than 0.4m/sec. The fish preferred a coarser ladder bed covered with small gravels, brush or carpet. 실뱀장어용 생태 어도를 설계하기 위하여 2008년 실뱀장어 소상 시기인 3~5월에 국립수산과학원 어군행동실험실에 실뱀장어가 소상하는 하구 및 하구둑과 어도를 재현하는모형 어도를 제작하여 다양한 소상 환경과 어도 조건에서실뱀장어의 소상행동을 관찰 분석하였다. 아래 해수조에 순치한 실뱀장어를 두고 위 담수조의 담수를 아래로 흐르게하면서 해수조에서 어도를 통해 담수조로 소상한 실뱀장어의 개체수를 비교하고, 실뱀장어의 소상 행동을 관찰하여최적 소상을 위한 적정 어도 조건을 추정하였다. 실뱀장어는 수돗물로는 소상하지 않았고, 저수지물보다 강물을 선호하였다. 실뱀장어 소상량은 소조기보다 대조기에 유의하게많았고(p⁄0.05), 낮보다 밤에 유의하게 많았다 (p⁄0.05). 실뱀장어 소상량은 저조위보다 고조위에서 유의하게 많았다 (p⁄0.05). 실뱀장어는 어도 경사면 길이가 짧을수록 소상량이 많았고, 경사도는 30℃이하가 효율적이었다 (p⁄0.05). 유속은 0.4 m/sec 이하로 물이 약하게 흐를 때 소상량이 많았다(p⁄0.05). 어도의 바닥은 솔, 자갈 및 카펫 등과같이 거친 재질에서 소상량이 유의하게 많았다(p⁄0.05).

금강하굿둑, 영암방조제, 아산만방조제 뱀장어 전용어도 모니터링

김재구,조윤정,박철우,김종욱,신유신,임민영,송영희,김원장,최윤 한국하천호수학회 2022 생태와 환경 Vol.55 No.2

The Ministry of Oceans and Fisheries promoted the installation of eel-ladder for the purpose of creating inland water resources. Currently, eel-ladder have been installed and operated at the Geumgang Estuary Bank (2018), Yeongam Embankment (2019), and Asanman Embankment (2020). In this study, the number of glass eels in eel-ladder in 2021 was monitored and factors affecting the rise that from ocean to river of eels were investigated. Glass eels in eel-ladder were found when the salinity was relatively low, and they started when the freshwater and seawater temperatures were above 20℃. Comparing the number of occurrences by year, the largest number of glass eels was observed in 2021, but it is judged that this is not according to the distribution of glass eels in sea, but rather as a result of the investigator’s eel-ladder repair and guidance on illegal fishing.

뱀장어(Anguilla japonica) 적정 사육관리를 위한 양식기술 현황

손맹현,김강웅,김경덕,김신권 한국수산과학회 2011 한국수산과학회지 Vol.44 No.4

This study was conducted to investigate the production, elver stocking, rearing facilities and rearing method of eel culture to determine aquaculture management conditions for optimal rearing of eel Anguilla japonica. The production of eel culture was evaluated by the proportion of eels from the main inland fin fish species production in Korea. Elver stocking was assessed by the elver stocking densities of pond and recirculation culture. Rearing facilities were investigated according to the rearing tank size proportion of the pond and recirculation culture. We selected sample farms by region and by size. We visited sample farms and recorded the number of elvers stock for pond area, size of tanks, feed and feed quantity, and the size and number of harvest eels. The production capacity of Jeollanam-do and Jeollabuk-do were 71.9% and 21.3% respectively. This production quantity represented 93.2% of the total Korean eel production quantity. In Jeollanam-do, there are 236 eel farms, 202 pond farms, and 34 recirculation aquaculture facilities. The elvers’ first density data by each aquaculture method revealed that elvers’ first density varied more in recirculation system farms, as compared to pond aquaculture. In intensive pond farms, the elvers’ first density decreased as the size of farm increased. There was a correlation between the size of tank(x) and the facility of a water wheel for dissolved oxygen in pond culture systems(y=0.022x-0.494; R^2=0.860). Another strong correlation was found between the weight of eel(x) and eel density(y) in pond culture systems(y=283.5x-0.27; R^2=0.992). Finally, there was a strong correlation between the length of eel(x) and the weight of eel(y) in intensive pond culture(y=0.0005x-3.2783; R^2=0.9775). The final survival rate did not differ significantly among pond sizes and culture types.

반건조 장어에 대한 식물 주정 추출물의 항산화 효과

송희순 한국식품저장유통학회 2019 한국식품저장유통학회지 Vol.26 No.1

Ethanol extracts from Ginger, cinnamon, dried onions, and Hutgae (Hovenia dulcis Thunb.) trunk were pre-treated on the eels to find out their peroxidation preventing properties on the eels. The eels were evenly coated with the extract equivalent to 2% of their total weight and dried for 15 h at 35℃ using an air blower. Antioxidative properties of ethanol extracts were reviewed through the DPPH scavenging effect, and the acid value, peroxide value, and linoleic acid value of the semi-dried eels, and also the delayed reaction of peroxidation of semi-dried eel oil. The highest level of DPPH scavenging was cinnamon extract, followed by Hutgae trunk extract, dried onions, and ginger (p<0.05). Regarding acid value of eels refrigerated for 21 days, ginger extract recorded the lowest. As in the preventative effect of free fatty acid, ginger extract prevented the early hydroperoxide during the drying process of eels. During the 20 days of peroxide-induced-reaction period, the most effective preventer of linoleic acid peroxide was Hutgae trunk extract and ginger and dried onion extracts were followed. During the 20 days of peroxide-induced-reaction period, the effective peroxidation preventers of semi-dried eel oil were ginger, cinnamon, and dried onions extracts. Hutgae trunk extract was found to delay effectively the peroxidation induction period of eel oil. In conclusion, pre-application of ethanol extracts from ginger and cinnamon was effective in delaying peroxidation of eels in the drying process and of semi-dried eels in refrigeration, and extracts from dried onions and Hutgae trunk were stalling the induced peroxidation and restricting peroxide content to some degrees.

첨가유가 무태장어 (Anguilla marmorata) 치어의 성장 및 어체 영양성분에 미치는 영향

서지훈(Ji-Hun Seo),유태식(Tae-Sik Yu),정복미(Bok-Mi Jung),김선재(Seon-Jae Kim),한경호(Kyeong-Ho Han) 전남대학교 수산과학연구소 2021 수산과학연구소논문집 Vol.30 No.2

As part of the study on formula feeds for marbled eel (Anguilla marmorata) culture, the growth performance, the basic and main nutritional composition in marbled eel fed diets with various types of additive oils were evaluated. The test show that fatty acid composition of eels fed fish oils (pollack and squid liver) was significantly different from those fed vegetable oils (soybean, olive, perilla and linseed). In the culture test of providing diets added with 10% of various oils, both weight gain rate and feed efficiency were higher in the order of eels fed diet with linseed oil>squid liver>perilla>other oils. Crude protein levels were not significantly different depending on the types of oil contained in the feed, and crude lipid contents in eels fed diets with pollack, squid liver and soybean oils were significantly higher than those fed diets with linseed and olive oils. Vitamin A (VA) and E (VE) contents also displayed a noticeable difference among eels fed additive oils, and VA in eels fed pollack and squid liver oil, and VE in eels fed pollack and squid liver and linseed oil found higher than eels fed other oils. Omega fatty acids such as DHA and EPA were highest in eels feddiets with squid liver oil. From this study it is confirmed that fatty acid composition of diet affects fatty acid composition of cultured marbled eels.

Characterization of ovarian culture in vitro and sex steroids in vivo by recombinant eel gonadotropin treatments in the eel Anguilla japonica

Dae-Geun Kim,김정현,백혜자,김신권,민관식,김대중 한국수산과학회 2022 Fisheries and Aquatic Sciences Vol.25 No.1

In the present study, we investigated the effects of recombinant eel gonadotropins (rec-GTHs) on maturation induction in immature ovarian culture in vitro and sex steroid hormones in vivo in the Japanese eel Anguilla japonica. To study the in vitro effects of rec-GTHs on estradiol-17β (E2) production in immature ovarian tissues, ovarian tissues were incubated with different doses of rec-follicle-stimulating hormone (rec-FSH) or rec-luteinizing hormone (rec-LH). The results revealed that the E2 levels in the rec-FSH (0.1, 0.5, or 1 μg/mL)- and rec-LH (0.1 or 0.5 μg/mL)-treated groups were significantly higher than those in the female eels from the control group. Furthermore, to investigate the in vivo effects of rec-GTHs on the gonadosomatic index (GSI) and plasma sex steroid hormone levels, the eels were injected intraperitoneally with eel’s ringer (control), salmon pituitary extract (SPE; for female eels), human chorionic gonadotropin (hCG; for male eels), rec-FSH, rec-LH, and rec-FSH + rec-LH once a week. The results revealed that except for the SPE and the hCG groups, none of the groups exhibited a significant difference in GSI values. However, in vivo plasma E2 levels increased at the end of 4 weeks after rec-FSH treatment in female eels. Based on these results, it is suggested that rec-GTHs may have a positive effect on sexual maturation in female eels; however, further studies on complementary rec-protein production systems and additional glycosylation of rec-hormones are needed to elucidate hormone bioactivity in vivo and in vitro.

Bacterial pathogens and flora isolated from farm-cultured eels (Anguilla japonica) and their environmental waters in Korean eel farms

Joh, S.J.,Ahn, E.H.,Lee, H.J.,Shin, G.W.,Kwon, J.H.,Park, C.G. Elsevier Scientific Pub. Co 2013 Veterinary microbiology Vol.163 No.1

The purpose of this study was to investigate bacterial pathogens and flora in both sick and clinically healthy eels, Anguilla japonica, and the environmental rearing waters of Korean eel farms. Between 2003 and 2010, a total of 621 sick eels were submitted for diagnosis, while 216 healthy eels and 87 environmental water samples were collected during a survey of 26 eel farms in Korea. Seven different bacterial species were obtained from 183 isolates, which were recovered from the internal organs of the 621 sick eels. The most frequently isolated bacterium was Edwardsiella tarda (71.0%), followed by Aeromonas hydrophila (9.3%), Citrobacter freundii (7.7%), Aeromonas veronii (6.0%), Listonella anguillarum (2.7%), Plesiomonas shigelloides (2.2%), and Pseudomonas anguilliseptica (1.1%). From the eel and water samples of the survey, a total of 472 isolates from 34 different species belonging to 15 genera of bacteria were isolated. The most prevalent genus of bacteria was Aeromonas spp. (14¼72, 29.8%). Among the 34 types of bacterial species, C. freundii (20.1%) and A. hydrophila (19.9%) were the most frequently isolated. The results of this study indicate that a wide range of bacterial species, which can act as primary or opportunistic pathogens, may be recovered from clinically healthy eels and rearing waters. This study provides baseline information about bacterial pathogens and floral contamination for the control and treatment of bacteria in Korean eel farms.

Korean Mistletoe (Viscum album Coloratum) Extract Induces Eel (Anguilla japonica) Non-specific Immunity

윤택준,박관하,최상훈 대한면역학회 2008 Immune Network Vol.8 No.4

Background: The immunomodulatory effects of Korean mistletoe (Viscum album Coloratum) on the innate immune responses of eel (Anguilla japonica) were studied. Methods: Mistletoe, Freund’s complete adjuvant (FCA), or phosphate- buffered saline (PBS) as a control was injected into eel peritoneal cavities. Results: Nitroblue tetrazolium(NBT)-positive cells in the head kidney of eel were significantly augmented by the second day post-injection of mistletoe. Reactive oxygen intermedia tes (ROI) were more produced in mistletoe-injected fish kidney leucocytes than in FCA-injected ones. The level of lysozyme activity in the serum of fish 2 days after injection with mistletoe was also significantly higher than that in the serum of the control fish. The optimal concentration of mistletoe in inducing the highest serum lysozyme activity was revealed to 500μg/200g of fish. In phagocytic activity assay, mistletoe-sensitized eel kidney phagocytes captured more zymosan than did the control fish. Conclusion: Korean mistletoe appeared to be a good activator of the non-specific immune responses of eel. Background: The immunomodulatory effects of Korean mistletoe (Viscum album Coloratum) on the innate immune responses of eel (Anguilla japonica) were studied. Methods: Mistletoe, Freund’s complete adjuvant (FCA), or phosphate- buffered saline (PBS) as a control was injected into eel peritoneal cavities. Results: Nitroblue tetrazolium(NBT)-positive cells in the head kidney of eel were significantly augmented by the second day post-injection of mistletoe. Reactive oxygen intermedia tes (ROI) were more produced in mistletoe-injected fish kidney leucocytes than in FCA-injected ones. The level of lysozyme activity in the serum of fish 2 days after injection with mistletoe was also significantly higher than that in the serum of the control fish. The optimal concentration of mistletoe in inducing the highest serum lysozyme activity was revealed to 500μg/200g of fish. In phagocytic activity assay, mistletoe-sensitized eel kidney phagocytes captured more zymosan than did the control fish. Conclusion: Korean mistletoe appeared to be a good activator of the non-specific immune responses of eel.