• Korean Journal of Environmental Biology
• /
• v.22 no.1
• /
• pp.111-119
• /
• 2004

The ichthyofauna and community structure in Lake Paro, Korea, was investigated from December 2002 to september 2003. Buying the surveyed period 45 species belonging 12 families were collected. There were 15 Korean endemic species 33.33％, including Hemibarbus mylodon, Aeheilognathus yamatsutae nnd Ooreoperca hem. Dominant species were Zacco platypus (72.41％) and subdominant species were Hemibarbus labeo (9.75％). Also, Opsariichthys uncirostris amurensis (5.98％), Zacco temmincki (2.42％), Rhinogobius brunneus (2.01％) and Hypomesus olidus (0.88％) were numerous. The biomass of collected fishes were Zacco platypus (82,803.15 g), Hemibarbus labeo (32,942.63 g), Opsariichthys uncirostris amurensis (27,482.39 g), Cyprinus carpio (6,502.87 g), Anguilla japonica (3,022.15 g) and Siniperca scherzeri (2,711.05 g). Of the 10 introduced fishes in Lake Paro Cyprinus carpio (Israeli type), Carassius cuvieri, Micropterus salmoides and Lepomis macrochirus were originated form foreign countries but Anguillta japonica, Hemiculter eigenmanni, Hypomesus olidus, Oncorhynchus masou mason, Chaenogobius urotaenius, Rhinogobius giurinus were introduced from other native river systems.

• 한국해양학회지
• /
• v.21 no.3
• /
• pp.146-155
• /
• 1986

Zooplankton samples of upper 50m layer in May, 1985 and of various depth intervals depending on thermal structure in October, 1985 were analyzed. Standing stock represents mean of 538inds/㎥ in spring and 267 inds/㎥ and 508inds/㎥ of whole column mean and surface layer in fall, respectively. A total of 55 and 104taxa is identified in each season and accumulated data list at least 123 species inhabiting in the study area. Copepods dominate in the zooplankton community, followed by protozoans and appendicularians in both seasons. In surface layer, distribution of subtropical species and standing stock seems to illuminate the effects of the Tsushima Current and the North Korean Cold Watermass in cold season, whereas only standing stock shows discernable variation in warm season. Concerning whole water column, depth of permanent thermocline bottom, at about 120m in fall 1985, plays significant role as a barrier to the distribution of mesopelagic cold water species. Serial sampling in October, 1985 does not reveal any perceivable diel vertical migration, which is considered to confirm the earlier suggest that owing to the lack of true abyssal species zooplankton biomass of deeper gayer is very poor, so that diel vertical migration of the East Sea is weak.

• Journal of the Korean Wood Science and Technology
• /
• v.39 no.1
• /
• pp.86-94
• /
• 2011

Pyrolytic lignin was obtained from biooil produced with yellow poplar wood. Fast pyrolysis was performed under various temperature ranges and residence times using fluidized bed type reactor. Several analytical methods were adopted to characterize the structure of pyrolytic lignin as well as the effect of pyrolysis temperature and residence time on the modification of the lignin. The yield of pyrolytic lignin increased as increasing pyrolysis temperature and decreasing residence time of pyrolysis products. The molecular weight of pyrolytic lignin determined by gel permeation chromatography (GPC) was approximately 1,200 mol/g, which was approximately a tenth of milled wood lignin (MWL) purified from the same woody biomass. Based on analytical data, demethoxylation and side chain cleavage reaction were dominantly occurred during fast pyrolysis.

• Korean Journal of Ichthyology
• /
• v.27 no.3
• /
• pp.205-216
• /
• 2015

Mobile macrofauna and community structure were studied at the Youngjong tiny tidepools, Incheon, Korea. Samples were monthly collected from February 2010 to January 2011. Mobile macrofauna community comprised a total of 18 species, including 1,122 individuals and 623.6 gWWt. The dominant species were Luciogobius guttatus, Tridentiger bifasciatus, Hemigrapsus penicillatus, Pagurus minutus. The number of species and biomass were low from December to March, and high from April to November. Canonical correspondence analysis revealed that temperature were the most important environmental variables in determining the observed variability in community composition. Species diversity indices ranged from 0.14 to 2.05, and showed the highest value in October 2010. The tide pools provide spawning ground and nursery ground for some fishes and decapods.

• Carbon letters
• /
• v.10 no.2
• /
• pp.114-122
• /
• 2009

Crushed, depitted peach stones were impregnated activated with 50% $H_3PO_4$ followed by pyrolysis at $500^{\circ}C$. Two activated carbons were produced, one under its own evolved gases during pyrolysis, and the second conducted with air flow throughout the carbonization stage. Physicochemical properties were investigated by several procedures; carbon yield, ash content, elemental chemical analysis, TG/DTG and FTIR spectra. Porosity characteristics were determined by the conventional $N_2$ adsorption at 77 K, and data analyzed to get the major texture parameters of surface area and pore volume. Highly developed activated carbons were obtained, essentially microporous, with slight effect of air on the porous structure. Oxygen was observed to be markedly incorporated in the carbon matrix during the air treatment process. Cation exchange capacity towards Cu (II) and Cd (II) was tested in batch single ion experimental mode, which proved to be slow and a function of carbon dose, time and initial ion concentration. Copper was up taken more favorably than cadmium, under same conditions, and adsorption of both cations was remarkably enhanced as a consequence of the air treatment procedure. Sequestration of the metal ions was explained on basis of the combined effect of the oxygen functional groups and the phosphorous-containing compounds; both contributing to the total surface acidity character.

• Journal of Forest and Environmental Science
• /
• v.24 no.3
• /
• pp.175-179
• /
• 2008

Forestry education in vocational high schools is one of the fundamental keys for achieving sustainable forest management. However, support systems for forestry education have not been well developed in Japan. Forest research institutes, which have accumulated relevant information, should have sufficient ability to develop new educational programs in this field. This study examined the possibility of support systems for forestry technical education by a research institute. Educational programs for vocational high schools were developed, and the programs were examined for their practical applications through a workshop for these teachers. We set the following five requirements for the programs: They should 1) incorporate new contents related to sustainable forest management, 2) be based on forestry education textbooks, 3) meet recent demands of the schools and society, 4) allow participants to learn through actual practice and experience, and 5) utilize readily available teaching materials. With these criteria, we developed the following two educational programs: (a) Forest management program to teach advanced techniques, (b) A timber-program to teach about biomass resources. The workshop was held on July $28^{th}$, 2007 with ten teachers attending. The programs were very interesting, who gave them high average evaluation of 4.6 on a scale of 1 to 5. Only a few issues need to be resolved before classroom instruction can begin, such as making wood structure easier to understanding for some teachers, and obtaining base maps of school forests. In conclusion, forest research institutes can effectively support forestry education by providing and implementing programs based on scientific information.

• Ocean and Polar Research
• /
• v.30 no.2
• /
• pp.181-191
• /
• 2008

This study aims at assessment of spatio-temporal distribution of demersal fish aggregations near the west coast of Jeju Island using hydroacoustic survey. A 200 kHz split beam transducer attached to a small towed body was used for all acoustic investigations. The received acoustic data were in situ acoustic target strength (TS, dB) for all pings and nautical area scattering coefficient(NASC, $m^2/mile^2$) for 0.1 mile along 12 acoustic transects. Demersal fish aggregations are distributed around the coastal slope having 20 to 30 m depth throughout all seasons. The concentration is higher during the summer season. With regard spatial distribution, higher demersal fish aggregations have been detected near the West coast of Shinchang and especially near Chagwi-do. Pelagic fish aggregations were higher to the south of Chagwi-do during the spring season. Additionally, standing stock of demersal fish aggregations from the NASC data, TS function, and length-weight function of dominant species was estimated as follows: 3.2 ton (CV 21.8%) in December 2006, 17.9 ton (CV 21.6%) in April 2007, 30.8 ton (CV 17.8%) in June 2007, and 22.5 ton (CV 24.2%) in October 2007. The application of hydroacoustic methods offers a new approach to understanding spatiotemporal structure and estimate the biomass of demersal fish aggregations in the coastal area. And the results can be made up limitations of qualitative analysis through net and diving for fisheries resources survey in coastal area.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.51 no.1
• /
• pp.79-90
• /
• 2018

Fish ages are critical information in fish stock assessments because they are required for age-structure models such as virtual population analysis and stochastic catch-at-age models, whose outputs include recruitment strengths, a spawning stock size (abundance or biomass), and the projection of a fish population size in future. However, most countries other than the developed countries have not identified ages of fish caught by fisheries or surveys in a consistent manner for a long time (e.g.,>20 years). Instead, data about fish body sizes (e.g., lengths) have been well available because of ease of measurement. To infer age compositions of fish in a target group using fish length data, we intended to improve the length frequency analysis (LFA), which Schnute and Fournier had introduced in 1980. Our study was different in two ways from the Schnute and Fournier's method. First we calculated not only point estimates of age compositions but also the uncertainty in those estimates. Second, we modified LFA based on the von Bertalanffy growth model (vB-based model) to allow both individual-to-individual and cohort-to-cohort variability in estimates of parameters in the vB-based model. For illustration, we used data about lengths of Korean mackerel Scomber japonicas caught by purse-seine fisheries from 2000-2016.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.5 no.2
• /
• pp.146-156
• /
• 2000

Zonation pattern of macro-invertebrate community structure was examined from Okjukpo sandy beach, Taechongdo, Korea. Macrofauna were collected in June 1998 using a can corer from ten stations along one transect. Mean grain size ranged from 1.97 to 2.23${\phi}$ and sediment organic contents ranged from 0.52 to 1.02%. A total of benthic macro-invertebrates comprised 25 species, providing 10,705 individuals and 89.13 g wet weight in biomass. Peracaridean crustaceans such as amphipods and isopods are the most prominant components in this exposed sandy beach. The dominant species were Eohaustorius setulosus (33%), Excirolana chiltoni (26%), Haustorioides koreanus (12%), Platorchestia crassicornis (8%), and Cycladicama cumingii (6%). The zonation patterns by these animals were very similar to those noted by Dahl(1952) and Jo(1990). They are divided into three faunal zones: 1) subterrestrial fringe dominated by a talitrid amphipod Platorchestia crassicornis, 2) midlittoral zone by a cirolanid isopod Excirolana chiltoni, 3) sublittoral fringe by more diverse amphipods communities.

• Korean Journal of Ecology and Environment
• /
• v.38 no.1 s.110
• /
• pp.63-72
• /
• 2005

The fish fauna and community structure were investigated in the Lake Cheongpyeong, Korea, from August 2003 to April 2004. During the period, 43 species belonging 10 families were collected. There were 18 Korean endemic species 41.9%. The five dominant species numerically were A. gracilis (17.4%), Zacco platypus (14.6%), A. yamatsutae (13.2%), Hemibarbus labeo (11.9%), Rhinogobius brunneus (11.7%), and Zacco temmicki (3.0%). The five dominant species in biomass were Erythroculter erythropterus (15.07 kg), H. labeo (13.21 kg), Carassius cuvieri (6.47 kg), A. gracilis (6.05 kg), and Z. platypus (4.71 kg). Of 6 exotic fishes in the lake C. cuvieri, Lepomis macrochirus and Micropterus salmoides were originated from foreign countries but Anguilla japonica, Tridentiger brevispinis, and Chaenogobius urotaenius were introduced from other watershed in Korea.