• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.6 no.1_2
• /
• pp.44-48
• /
• 1973

Since no medium-sized anchovies for skipjack baits are caught during the winter season in the Korean waters, the demand for the live baits in the winter season is met with crawl-stocked anchovies. Authors conducted a test on the wintering of the anchovies which were caught in the early November and acclimated for 22days in a crawl. The wintering crawl was kept in the inlet near Chungmu City, which is situated in the southern coast of Korea, for 4 months through December 1, 1971 to March 31, 1972. 1. The lowest water temperature of $7.2^{\circ}C$ recorded on March 1, caused no significant mortality of the wintering anchovies. However, two operations, moving the crawl and repacling the crawl webbing, brought about a considerable mortality. The mortality of the anchovies, due to the crawl moving to the wintering place two kilometers away from the transient acclimating place, amounted to 1.5 percent in 9 days following the crawl moving. The replacement of the fouled crawl webbing with a new one also caused a mortality amounting to 1.7 percent in 5 days. 2. It is judged that the favorable wintering waters lie in the south and southeast coasts of Keoje Island, the south and southwest coast of Chungmu City, coasts around Namhae Island, and the east coast of Dolsan Island. Jinhae Bay is not suited for the wintering because of its low water temperature in winter 3. The wintering anchovies wvere fed, once a day through the test period, with 4 kg of finely minced fresh anchovy for 57days in the early period, and with 2kg of compound pellet fish food for the rest of the period. Fatness coefficient of the wintering anchovies showed a slight increase in the latter half of the period.

• Journal of Microbiology
• /
• v.45 no.6
• /
• pp.541-546
• /
• 2007

Red algae are distributed globally, and the group contains several commercially important species. Griffithsia okiensis is one of the most extensively studied red algal species. In this study, we conducted expressed sequence tag (ESTs) analysis and synonymous codon usage analysis using cultured G. okiensis samples. A total of 1,104 cDNA clones were sequenced using a cDNA library made from samples collected from Dolsan Island, on the southern coast of Korea. The clustering analysis of these sequences allowed for the identification of 1,048 unigene clusters consisting of 36 consensus and 1,012 singleton sequences. BLASTX searches generated 532 significant hits (E-value <$10^{-4}$) and via further Gene Ontology analysis, we constructed a functional classification of 434 unigenes. Our codon usage analysis showed that unigene clusters with more than three ESTs had higher GC contents (76.5%) at the third position of the codons than the singletons. Also, the majority of the optimal codons of G. okiensis and Chondrus crispus belonging to Bangiophycidae were G-ending, whereas those of Porphyra yezoensis belonging to Florideophycidae were G-ending. An orthologous gene search for the P. yezoensis EST database resulted in the identification of 39 unigenes commonly expressed in two rhodophytes, which have putative functions for structural proteins, protein degradation, signal transduction, stress response, and physiological processes. Although experiments have been conducted on a limited scale, this study provides a material basis for the development of microarrays useful for gene expression studies, as well as useful information for the comparative genomic analysis of red algae.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.49 no.3
• /
• 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.

• Korean Journal of Ichthyology
• /
• v.31 no.3
• /
• pp.172-177
• /
• 2019

Seasonal fluctuation in abundance and species composition of fish in coastal waters off Dolsan island were investigated using seasonal samples collected by an otter trawl in 2012. A total of 4,848 fishes were sampled and classified into 52 species, 29 families, and 7 orders. The dominant species was Leiognathus nuchalis (2,786 individuals, 57.5%), Amblychaeturichthys hexanema (164 individuals, 3.4%), and Ilisha elongata (141 individuals, 2.9%). The highest number of individuals was found in summer (2,174 individuals), while the lowest number of individuals was found in winter (321 individuals). The diversity index was the highest in spring (H'=3.06) and the lowest in summer and fall (H'=1.77). Temperature was the principal factor to determine the collected number of individuals (r=0.94) and the number of species (r=0.83).

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.13 no.3
• /
• pp.151-164
• /
• 2010

Field observations on the seasonal variations of environmental factors and phytoplankton community were carried out four times at 30 stations in the narrow strait between Yeosu and Dolsan Island of the Korean South Sea from September 2005 to May 2006. The ranges of water temperature, salinity and extinction coefficient in the surface waters were 5.6~26.3, 25.36~33.92 psu and 0.13~2.13, respectively. The water temperature measured higher at Gamak Bay in summer and spring. It measured higher at Yeosuhae Bay in autumn and winter. Salinity showed uniformity of distributions in almost all areas, except for an area near a sewage disposal outlet. Extinction coefficient indicated that the turbidity of Gamak Bay and the area near the sewage disposal outlet were higher than that of the Yeosuhae Bay. In the phytoplankton community were identified a total of 99 species belonging to 51 genera. The species composition showed itself to be various in summer and autumn, but poor in winter and spring with a high ratio of centric diatoms all the year round. Seasonal succession of dominant species were Skeletonema costatum and Chaetoceros curvisetus in summer, Eucampia zodiacus in autumn and winter, and Chaetoceros affinis and Thalassionema nitzschioides inspring. Standing crops of phytoplankton and Chlorophyll $\alpha$ concentration were greatly higher at Gamak Bay in summer with ranges of $0.2{\times}10^4\;cells\;L^{-1}$ to $296{\times}10^4\;L^{-1}$, and $1.94\;L^{-1}$ to $22.12\;L^{-1}$, respectively. From the results of principal component analysis (PCA), the northern part of Dolsan Island was divided into two or three regions from the characteristics of marine environment and phytoplankton community.

• Korean Journal of Ichthyology
• /
• v.25 no.2
• /
• pp.82-89
• /
• 2013

The spawning behavior, development of eggs and larvae of the Five striped damselfish, Abudefduf vaigiensis were studied. The Five striped damselfish were caught at Dolsan Island, Yeosusi, Jeollanamdo from May in 2011. As a result of observation, male fish attracted female after cleaning the rock. Female left after spawning and male protected their eggs until they had hatched out. The fertilized eggs were elliptical in shape (mean long diameter: 1.06 mm; mean short diameter: 0.55 mm) and transparent. Larvae hatched at 53 hrs after fertilization in $24.5{\sim}26.5^{\circ}C$(mean $25.0^{\circ}C$). The newly hatched larvae were 2.55~2.86 mm (mean 2.71 mm, n=10) in total length and their mouth and anus were already opened. They began to eat rotifer and transformed to postlarva stage. 3 days after hatching postlarva was measured 2.74~2.97mm(mean 2.84 mm, n=10) in total length. 10 days after hatching postlarva was measured 3.85~4.20mm(mean 4.00 mm, n=10) in total length with dosal fin rays IV-5; ventral fin rays I-3; caudal fin rays 1~2.