• Ocean and Polar Research
• /
• v.23 no.3
• /
• pp.311-313
• /
• 2001

Eighteen species of fish were identified by SCUBA diving observations around experimental artificial reefs at Tongyeong marine ranching area between November 1998 and November 1999. The highest species number of 14 was observed in September while the lowest number of 2 was observed in November. Fishes showed three typical behavioral patterns against the experimental artificial reef.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.40 no.5
• /
• pp.308-314
• /
• 2007

The feeding habits of Sebastes schlegeli collected from the Tongyeong marine ranching area throughout 2002 were studied. S. schlegeli is a carnivore (piscivore), and consumed mainly fish. Its diet also included a small amount of caridean shrimps, crabs, amphipods, polychaetes, and isopods. The diet of S. schlegeli underwent size-related changes. Small individuals (standard length (SL)<6 cm) fed mainly on fishes, caridean shrimps, and amphipods, and the proportion of fish increased with SL. Large individuals (SL>20 cm) ate fish predominately. The diet of S. schlegeli changes seasonally, and caridean shrimps were consumed mainly from May to July. The dietary breadth index of S. schlegeli varied with SL and season.

• Korean Journal of Environmental Biology
• /
• v.22 no.1
• /
• pp.75-82
• /
• 2004

Surface and bottom sea water samples were harvested from the 5 stations in the marine ranching ground of Tongyeong coastal water from year 2000 to 2002. Cell number of heterotrophic bacteria was determined by using the plate counting method to explore the variation of the cell population of heterotrophic bacteria. Sea water samples collected in summer (in July and August) contained much larger number of heterotrophic bacteria than those harvested in spring, autumn and winter. Heterotrophic bacteria were usually more abundant in surface sea than in bottom sea water. However the reverse was true for sea water collected in December 2001 and February 2002 due to suspended solids accumulating more abundantly in seabed area because of the slower convective current of the sea water in winter. Number of heterotrophic bacteria did not have a strong relationship with frequency of typhoon indicating that the path and powerfulness of the typhoon, localized torrential downpour and temperature variation accompanying the typhoon should be considered all together at the same time as well as the frequency of typhoon to explain clearly the variation of cell number of heterotrophic bacteria. The dominant species isolated from the marine ranching ground of Tongyeong were identified to be Pseudomonas fluorescens, Pseudomonas stutzeri, Acinetobacter lwoffii and Sphingomonas paucimobilis.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.55 no.2
• /
• pp.105-120
• /
• 2019

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.

• Korean Journal of Ichthyology
• /
• v.19 no.1
• /
• pp.35-43
• /
• 2007

Age and growth of black rockfish, Sebastes schlegeli sampled from the Tongyeong marine ranching area in Korea waters were determined from 1,173 otoliths from July, 2001 to May, 2004. Examination of outer margins of the otolith showed that the opaque zone was formed once a year. Marginal increment of the otolith formed annual ring from July. The von Bertalanffy growth curve had the growth parameters estimated from non-linear regression were $L_t=48.45(1-e^{-0.2139(t+0.4313)})$, $W_t=1,837.93(1-e^{-0.2139(t+0.4313)})^{3.02}$ 3.02 for females and, $L_t=49.32(1-e^{-0.1775(t+0.7403)})$, $W_t=1,887.83(1-e^{-0.1775(t+0.7403)})^3$ for males, where t is age (year) and Lt is body length (mm) at age t. Growth at the age of male and female shows significant difference (p<0.01).

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.37 no.3
• /
• pp.249-254
• /
• 2004

The hydro-acoustic method is widely used for estimating biomass and distribution of fisheries resources along the coast and in the ocean. High costs and time are necessary to construct systems for this method and to initially educate specialists. It has been used in fisheries of advanced nations like Japan and Norway, because it is more efficient than other methods. In order to research the behavior of fish around an artificial reef using an echo sounder, volume backscattering strength (SV) and fish per cubic meter (FPCM) of darkbanded rockfish around the model artificial reef in a water tank were measured. Moreover, behavior of fish was observed in an adjacent artificial reef, which was constructed at Tongyeong marine ranching area. Following that, an acoustics survey was conducted at Mirukdo around the Tongyeong marine ranching area, in order to understand the spatial distribution and strength of fisheries resources. Very high patches of fish were found in a wide area around the artificial reef. It is thought that an approaching fish school around the artificial reef can be measured accurately by using an echo sounder of high resolution. Moreover, use of other monitoring methods like of diving or ROV simultaneous with an echo sounder is required in order to grasp the species and ecology of fish inhabiting the area around the artificial reef.

• Fisheries and Aquatic Sciences
• /
• v.9 no.2
• /
• pp.91-96
• /
• 2006

The movement range and diurnal behavior of 17 wild black rockfish (Sebastes schlegeli) were monitored within the marine ranching area of Tongyeong from 27 July to 7 November, 2005 using acoustic telemetry. Coded transmitters were surgically implanted into the abdomen of fish. Two of ten fish released in summer moved about 2 km away from the capture point for 1 day. The others stayed within a 500-m radius of the release point for 1 week after release. The seven fish released in autumn stayed within 500 m of the release point. Most fish were more active and had a greater range of horizontal diurnal movement at night than during the day. Additionally, the range of horizontal diurnal variation was greater in summer than in autumn. While fish released in summer were more vertically active at night than during the day, those released in autumn preferred to move vertically during the day.

• Korean Journal of Environmental Biology
• /
• v.24 no.2 s.62
• /
• pp.138-146
• /
• 2006

The effects of night-lights on feeding by the black rockfish Sebastes inermis in the cage of the Tongyeong marine ranching area were investigated by analyzing the stomach contents of 200 individuals from July 2004 to August 2004. In night-lights groups, black rockfish consumed mainly copepoda, amphipoda and polychaeta; also those in control area fed on copepods, amphipods and polychaets. Copepods (57%) and amphipods (32%) were the major prey organisms for all study period in night-lights. While, major prey items in control area were copepods (88%). Growth of the black rockfish reared in night-lights conditions were significantly higher than that of those in control area.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.41 no.3
• /
• pp.221-227
• /
• 2008

The black rockfish (Sebastes schlegeli) is an important commercial species in Korean fisheries. We used acoustic telemetry using coded ultrasonic transmitters to track the home ranges and homing routes of the black rockfish that inhabit in the Tongyeong marine ranching area. Twenty-four fish were released at five points. The distance from the capture point (C1) to the released point was 0 (R7), 0.2 (R1), 0.9 (R2), 1.3 (R3) and 1.9 (R4) km. Two of the three fish released at R1 (0.2 km) returned home in under 48hrs. Another was found 0.8km from C1. Two of the five fish released at R2 returned home, but it took over 250 days. None of the ten fish released at R3 and R4 returned home. Three of the ten fish moved 1.1-2.6 km from C1 and were found near a cage or a natural reef. Six fish were released at R7. The younger the fish, the wider was its movement range around the artificial reefs. Fish over 3 years old were likely to move less far.

• Korean Journal of Environmental Biology
• /
• v.24 no.2 s.62
• /
• pp.126-137
• /
• 2006

Effect of night-lights on zooplankton attraction has been studied in Tongyeong marine ranch area during the period from 12 July to 30 August, 2004. Each sampling has been carried out to collect zooplankton from both control area in natural waters experiment area of night-lights waters at night. A total of 43 taxa of zooplankton occurred during the study. Copepods showed the prosperity in species number with 15 species. Acartia erythraed and Copepodite occurred abundantly in night-lights waters. Zooplankton abundance appeared to increase in night-lights mainly due to the gathering of copepods and larvae through the study period. Average $3\sim166$ times of zooplankton abundance was recorded in night-lights when compared with that in control area of natural waters due to the gathering of copepods and larvae. Cluster analysis, based on monthly abundance data of the 13 most frequent species, showed that the species were seperated into two different groups: the photo-positive group and the photo-negative group.