• 한국어류학회지
• /
• 제35권2호
• /
• pp.113-120
• /
• 2023

이번 연구에 사용된 고등어는 2022년 1, 3~5, 7~9, 11월에 제주도 주변 해역에서 대형선망, 소형선망어업에 의해 어획된 959개체를 이용하였으며, 전장(Total length)과 체중(Body weight)을 각각 0.1 cm와 0.1 g 단위까지 측정한 뒤, 위를 적출하여 먹이 생물의 크기와 무게를 측정하고 가능한 종 수준까지 분석하였다. 위내용물 분석 결과는 상대중요도지수비를 이용하였으며, 계절과 크기군에 따른 먹이조성 변화를 알아보았다. 고등어의 가장 중요한 먹이생물은 난바다곤쟁이류(Euphausiacea)였으며, 그 다음으로 중요한 먹이생물은 어류(Pisces)로 나타났다. 그 외에, 단각류(Amphipoda), 요각류(Copepoda), 새우류(Caridea), 게류(Brachyura), 두족류(Cephalopoda) 등이 출현하였으나, 0.8% 이하의 상대중요도지수비를 보여 그 양은 매우 적었다. 계절별 위 내용물 조성을 살펴본 결과, 봄, 여름, 가을철에는 난바다곤쟁이류를 주로 섭식하였으며, 여름철에 비율이 가장 높게 나타났다. 겨울철에는 어류가 가장 중요한 먹이생물로 나타났다. 또한 크기 군별 위내용물 조성을 알아본 결과, 모든 크기군에서 난바다곤쟁이류가 가장 우점하였으나, 성장함에 따라 난바다곤쟁이류의 비율은 감소하고 어류의 비율이 증가하는 경향을 보였다. 고등어는 성장함에 따라 개체당 평균 먹이생물의 개체수는 통계적으로 유의한 차이를 보이지 않았으나, 먹이생물의 중량은 통계적으로 유의한 차이를 나타냈다.

• Bulletin of the Korean Chemical Society
• /
• 제34권8호
• /
• pp.2408-2412
• /
• 2013

We demonstrate herein the synthesis and modification of magnetic nanoparticles and its use in the immobilization of the lipase. Magnetic $Fe_3O_4$ nanoparticles (MNPs) were prepared by simple co-precipitation method in aqueous medium and then subsequently modified with tetraethyl orthosilicate (TEOS) and 3-aminopropyl triethylenesilane (APTES). Silanization magnetic nanoparticles (SMNP) and amino magnetic nanomicrosphere (AMNP) were synthesized successfully. The morphology, structure, magnetic property and chemical composition of the synthetic MNP and its derivatives were characterized using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) analysis, X-ray diffraction, superconducting quantum interference device (SQUID) and thermogravimetric analyses (TGA). All of these three nanoparticles exhibited good crystallization performance, apparent superparamagnetism, and the saturation magnetization of MNP, SMNP, AMNP were 47.9 emu/g, 33.0 emu/g and 19.5 emu/g, respectively. The amino content was 5.66%. The AMNP was used to immobilize lipase, and the maximum adsorption capacity of the protein was 26.3 mg/g. The maximum maintained activity (88 percent) was achieved while the amount of immobilized lipase was 23.7 mg $g^{-1}$. Immobilization of enzyme on the magnetic nanoparticles can facilitate the isolation of reaction products from reaction mixture and thus lowers the cost of enzyme application.

• 한국수산과학회지
• /
• 제49권5호
• /
• pp.642-647
• /
• 2016

Postlarval and juvenile anchovies Engraulis japonicus were collected using a gape net with wings in the coastal waters of Yeosu in July and August 2015, and their gut contents were analyzed. The size range of the postlarvae was 11.0-24.2 mm (notochord length) and that of the juveniles was 25.1-37.4 mm (standard length). Guts were empty in 64.5% of postlarvae and in 51.7% of juveniles. The dominant prey organisms in the guts of both postlarvae and juveniles were copepoda. Calanoida were important prey organisms for postlarvae and were dominated by nauplii of Paracalanus sp. and Calanus sp. as well as unidentified copepod naupill. Calanoida were also important in the diets of juveniles, whose gut contents were dominated by Paracalanus sp. and Cirripedia. Gut compositions were significantly different (P<0.05) among three body size levels in postlarvae and juveniles. As the body size of the postlarvae and juveniles increased, Calanoida constituted a larger proportion of the gut contents, while the proportion of copepod nauplii decreased.

• 한국수산과학회지
• /
• 제55권5호
• /
• pp.590-597
• /
• 2022

We analyzed the diet composition of smallmouth argentine Argentina kagoshimae, which were collected via bottom trawl in the South Sea during February, April, August, and October 2021. Their size range was 8.1-21.4 cm total length. A. kagoshimae are mesopelagic carnivores, mainly consuming benthopelagic Euphausiacea and Caridea crustaceans. Polychaetes were the second largest prey component in their diet, which also included small quantities of copepods, amphipods, and arrow worms. Stomach content compositions substantially differed among body size levels in A. kagoshimae. The results of non-metric multidimensional scaling ordination and permutational multivariate analysis of variance of dietary data revealed no significant dietary differences. The results of a graphical analysis of the diet composition showed that A. kagoshimae are specialized feeders characterized by strong individual feeding specialization.

• 수산해양기술연구
• /
• 제49권3호
• /
• pp.250-260
• /
• 2013

The annual and monthly fluctuation in the species composition and the catch abundance of dominant species were analyzed using the daily sales slip catch data by a set net in the offshore waters off Dolsan Island in Yeosu from March 2004 to December 2011. Mean catch from 2004 to 2011 is 372M/T and the maximum and the minimum catch are 526 M/T in 2005 and 27 2M/T in 2009, respectively. The dominant species were Engraulis japonicus mainly in spring and Scomberomorous niphonius in Autumn and therefore the set net catch that is dominated by S. niphonius's catch was much higher in autumn than in spring. Through comparative analyses for the environmental factors to the annual catch fluctuation, it is revealed that the water temperature variation affected the recruitment property of S. niphonius to the fishing ground but the effect of typhoon on the catch fluctuation was not distinct. Furthermore, the big blooming event of jellyfish, particularly Nemopilema nomurai, that occurred in 2009 showed a tendency of faster appearance and later extinction until December. The occurring characteristic of N. nomurai became a direct cause that brought about the lowest total catch in 2009 since the dominant species catch of the set net fishery was concentrated mostly in Autumn.

• 수산해양기술연구
• /
• 제55권3호
• /
• pp.243-251
• /
• 2019

The ichthyoplanktons were sampled by Bongo net to study the distribution of the eggs and larvae in the West coastal waters of Korea during the study period (February, May, August and October of 2017). Collected fish eggs were divided into Engraulis japonicus and unidentified species. The most dominant species, Engraulis japonicus accounted for 79.52% of the total fish egg, which was followed by unidentified species (20.48%). The total of 36 taxa in fish larvae were identified based on morphological and molecular characteristics. Fish larvae were dominant by Gobiidae species. 48.30% of the total catch in abundance, which was followed by Engraulis japonicus (31.86%). These two taxa composed 80.16% of the total collected fish larvae. The seasonal diversity index of species from the collected fish larvae in the West coastal waters in 2017 was 0.625-1.883 and the evenness index was 0.380-0.865. In addition, dominance index was 0.618-0.920 and richness was 0.573-3.189.

• 수산해양기술연구
• /
• 제46권4호
• /
• pp.292-301
• /
• 2010

For an effective management of fisheries resources, it is very important that to make clean inhabitation environment and to preserve fisheries resources. The material which is mainly used as fishing gear in modern times, is polyethylene, polypropylene, polyamide, etc., chemical fiber. And lost fishing gears which are make of these, occur ghost fishing and ocean pollution. To solve these problem, we development biodegradable fishing trap using the polybutylene succinate (PBS). Developed traps are for red snow crab (Chionoecetes japonicus) and shrimp, major traps in the East Sea, and we carried out fishing research using two kind traps in the coastal sea of Ayajin-port (Goseong) to analysis fishing efficiency of PE trap and PBS trap. As a result for fishing experiment (year 2005-2006) of red snow crab trap, two kind traps were almost the same in catches and length composition. During a experiment, parts of meshes, used for over 1 year, were cut by biodegradation. As a result for fishing experiment (year 2007) of shrimp trap, northern shrimp (Pandalus eous), coonstripe shrimp (Pandalus hypsinotus) and morotoge shrimp (Pandalopsis japonica) were catched, and the almost is northern shrimp. Two kind traps were almost the same in catches and length composition. In accordance with these result, it is recommended that the developed traps are have to commercialized because the fishing powers of PE traps and PBS traps were same. But biodegradation speed is have to controled in consideration of ocean microorganism volume and traps life.

• 한국수산과학회지
• /
• 제54권4호
• /
• pp.517-525
• /
• 2021

Trawl fishing is a major concern worldwide, and there is considerable debate about its impact on marine ecosystems. In this study, we used the vessel monitoring system (VMS) data collected in the southwest Atlantic Ocean from 2016 to 2019 to estimate the fishing effort and trawled area. Spatial distribution of trawl activities according to the latitude and longitude and the hotspots where fishing was concentrated each year were identified. Trawling activities of the Korean vessels were mainly distributed between 40-52°S and 56-63°W. The species caught during the fishing period comprised five Cephalopoda, three Chondrichthyes, ten Osteichthyes, and other fish. The Argentine hake Merluccius hubbsi and Argentine shortfin squid Illex argentinus were the dominant species in the catch.

• 수산해양기술연구
• /
• 제56권2호
• /
• pp.94-104
• /
• 2020

An ecological study for species composition and abundance of the fish assemblages in the coastal waters of Gujora and Mangchi of Geoje, Korea was conducted using monthly larval collection by an RN80 net from June, 2018 to May, 2019. A total of the 5 Orders, 15 Families, 21 species were collected. The dominant species were Ammodytes japonicus and Engraulis japonicas. Gobiidae was the most dominant species in June, Spratelloides gracilis in July, Chelidonichthys sp. in August, Gobiidae in September, Repomucenus beniteguri in October, Sebastiscus marmoratus in November, Sebastiscus marmoratus and Hexagrammos otakii in December of 2018, Pleuronectes yokohamae in January, Ammodytes japonicus in Febraury, Engraulis japonicus in March, Sebastes sp. and Gobiidae in April and Engraulis japonicus in May of 2019. The highest number of species and individuals were found in July and the smallest in August. Thus, the diversity index was the highest in July and the lowest in August. As a result of the similarity by month was divided into Group I in January and February and Group II in April, June and September. The most dominant species in the Group I were the Ammodytes japonicus and Sebastes inermis, and the most dominant species in the Group II was Gobiidae.

• 한국수산과학회지
• /
• 제31권5호
• /
• pp.739-748
• /
• 1998

1995년 5월, 9월, 11월에 영광군 연안에서 오터트롤로 채집한 수산생물의 종조성을 파악하고, 같은 시기에 주목망에서 채집된 부영생물과 비교하여 영광 근해 수산자원의 특성을 구명하였다. 영광군 연안에서 조사기간 동안 총 73종의 수산생물이 출현하였으며, 이중어류 $63\%$, 두족류 $5\%$, 복족류 $3\%$, 게류 $14\%$, 새우류 $14\%$이었다. 개체수에서 민태 (Johnius grypotus), 그라비새우(Palaemon gravieri), 마루자주새우 (Crangon hakodatei), 참서대 (Cynoglossus joyneri), 눈강달이 (Collichthys niveatus)가 전체의 $64.4\%$를 차지하여 우점하였다. 같은 시기에 같은 정점에서 채집한 주목망에 의한 자료와 비교한 결과, 전반적으로 주목망에는 부영생물이, 오터트롤에는 저서수산생물이 우세하여 채집방법에 따른 종조성의 차이를 보였다.