• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.44 no.3
• /
• pp.290-297
• /
• 2011

The phenology of Campylaephora hypnaeoides J. Agardh and optimal conditions for carpospore release, growth and reproduction were examined in the field and in the laboratory from January to December 2007. In the field population of C. hypnaeoides, approximately 50% of the plants were vegetative during the study period. Additionally, the percentages of carposporophytes and tetrasporophytes were maximal in April (37%) and June (57%), respectively. Maximum growth in plant length, dry weight, and hook number coincided with the tetrasporophyte reproductive peak in the field. In culture, carpospore release, sporeling growth and reproduction were affected by environmental factors such as daylength, temperature, and salinity. The liberation of carpospores was maximum under continuous light and at a combination of $15^{\circ}C$ and $10\;{\mu}mol$ photons $m^{-2}\;s^{-1}$. Maximum growth of tetrasporophyte sporelings occurred at a combination of $20\;{\mu}mol$ photons $m^{-2}\;s^{-1}$ of constant light and $25^{\circ}C$. However, the growth of gametophyte sporelings was maximal under $40\;{\mu}mol$ photons $m^{-2}\;s^{-1}$ of constant light and in a combination of $20^{\circ}C$ and 35 psu. The tetrasporophyte sporelings were grew faster than gametophytes, indicating that gametophyte- and tetrasporophyte-sporelings have different physiological responses to irradiance and temperature. Tetrasporangial branches and cystocarps of C. hypnaeoides were produced from carpospores and tetraspores within 1 month, and they were stimulated at high temperature and irradiance levels. In conclusion, C. hypnaeoides should be seeded using carpospores during early winter (November-December) because cystocarps are easily identified by fishermen, and tetrasporophytes grow faster than gametophytes.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.35 no.6
• /
• pp.578-582
• /
• 2002

Ethanol extract obtained from bark, roots, stem, leaves and seeds of 30 species of plants and mushroom, Dicyophora indusiata were examined antimicrobial effect on fish pathogenic bacteria, Listoneria anguillamm, Lactococcus garvieae, Streptococcus iniae by disk method. Ethanol extract of D. indusiata was found to be the most active against all fish pathogenic bacteria in test system. Ethyl acetate fraction from ethanol extract of D. indusiata showed the strongest compared with those from other solvent fractions such as dichloromethane, n-buthanol and water. The antimicrobial effect of ethyl acetate fraction was particularly evident against S. iniae.

• Journal of Animal Environmental Science
• /
• v.6 no.2
• /
• pp.83-89
• /
• 2000

In general, livestock wastewater consists of many pollutants such as nitrogen, phosphorus, carbonic compounds and inorganic substances. Most carbonic and organic compounds are sufficiently removed by conventional secondary processes, but nitrogen, phosphorus and soluble inorganic compounds are little removed by traditional clarification process. These remained substances in wastewater, for instances, phosphorus and nitrogen are efficiently eliminated by advanced wastewater treatment or botanical removing process. Concentrations of $BOD_s$, SS, T-N and T-P in influent livestock wastewater used in this study were 126mg/l, 115mg/l, 45mg/l and 13mg/l, respectively. The hydraulic retention time(HRT) of wastewater was about 10 days in the pond packed with aquatic plants. A water-hyacinth and a water-dropwort were used as an experimental stuff plant. The removal ratios of nitrogen was 44.3% for the water-hyacinth and 40.2% for the water-dropwort. The removal efficiency of phosphorus in experimental ponds reached by 57.9% for the water-hyacinth and 58.5% for the water-dropwort for 10 days, respectively. Removal ratios of BODs and SS of livestock wastewater for 10 days were reached by 80.1%, 91.0% for he water-hyacinth, respectively. At the same condition, the removal ratios of BODs and SS were reached by 75.0%, 87.6% for the water-dropwort, respectively.

• Journal of Environmental Impact Assessment
• /
• v.21 no.2
• /
• pp.229-238
• /
• 2012

This research was to examine the physiochemical factors and the attached diatoms of ecological wetland in Paju from August 2010 to May 2011. As a result of physicohemical water quality assessment, the water temperature did not fluctuate much due to ample riparian vegetation and aquatic plants growing at the site. Due to the effect of Han River Estuary, site 4, 5 and 6 had high electricity conductivity. The BOD concentration was high at site 2, 3, and 4 caused by decrease in water quantity and inflow of polluted water. At all sites, T-N and T-P concentrations ranged from eutrophic to hypertrophic status. At the downstream, the T-N and T-P concentrations decreased by inhabiting aquatic plant. Total of 98 taxa of attached diatoms were found. As for dominant taxa, Achnanthes convergens, A. minutissima, Gomphonema gracile, G. parvulum, Melosira varians, Navicula seminulum, N. minima, N. pseudolanceolata, Nitzschia amphibia, N. palea, Surirella minuta and Synedra ulna var. fragilariodes appeared. The result of biological assessment of water quality rated the sites B(suboptimal)~D(poor) during seasons of low water temperature, Fall and Winter, with DAIpo ranging 24.1~68.2 and TDI of 48.4~85.6. During Spring and Summer, all sites were rated D(poor) with DAIpo lower than or equal to 40, and TDI above or equal to 70. The biological assessment of water quality at the research site showed inferior TDI result compared to that of DAIpo.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.43 no.5
• /
• pp.391-399
• /
• 2010

This study was conducted to improve the antioxidative activity of instant noodles containing enzymatic extracts from Ecklonia cava (EEC). EEC has relatively better antioxidative activity than extracts from other indigenous plants in Jeju Island. The EEC (2.5 mg/mL) had 82.5% for the hydroxy radical, 78.4% for the DPPH radical, and 64.9% for the superoxide anion radical scavenging activities, and 65.2% for the cell viability (100 ${\mu}g/mL$). According to the texture of the dough, the DPPH free radical scavenging of uncooked instant noodles, sensory evaluation of cooked instant noodles, and turbidity of the cooking drip, the optimal EEC concentration was 1.8% for the instant noodles. The major amino acids in the instant noodles with EEC were glutamic acid (24.2%), proline (10.2%), valine (10.0%), and isoleucine (12.3%). The zinc and iron in the instant noodles were enhanced by adding 1.5-1.8% EEC. The antioxidant activity of instant noodles with EEC was 75.4% for the hydroxy radical, 74.1% for the DPPH radical, and 51.2 % for the superoxide anion radical scavenging activities.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.47 no.6
• /
• pp.1006-1013
• /
• 2014

Wastewater organic compounds, that is, nonylphenolic compounds (NPs) and fecal sterols, were measured in surface sediments from Busan Suyeong Estuary, where two wastewater treatment plants (WWTPs) are located, to assess contamination from municipal effluents. The NPs analyzed were nonylphenol, and nonylphenol mono- and di-ethoxylates, all synthetic endocrine disruptors. The fecal sterols analyzed were coprostanol (COP), cholestanol, and epicoprostanol. Concentrations of NPs in the sediments ranged from 146 to 3,723 ng/g, and those of COP ranged from 366 to 13,018 ng/g. Their detection in all of the sediments analyzed indicates widespread pollution by municipal effluents. The highest concentrations of NPs and COP were detected at stations close to outfalls of WWTPs. Their levels in sediments are categorized in the higher range of those previously reported in Korean coastal areas. Moreover, in comparison with screening values of NPs in the Netherlands, Norway, and Canada, more than 50% of the sampling stations exceeded the guidelines. This indicates that the estuary may be adversely influenced by municipal effluents.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.54 no.4
• /
• pp.411-417
• /
• 2021

By-products produced from medicinal plants (MP) were evaluated as feed additives on growth performance, blood chemistry, and immune responses of the juvenile red lip mullet Liza haematocheila. A commercial diet was used as the control. Four experimental diets were prepared by combining 0.5% of MPs such as Panax ginseng (PG), Schisandra chinensis (SC), Angelica gigas (AG), and Rehmannia glutinosa (RG), via water absorption, to the control diet. Triplicate groups of fish averaging 61.8 g were fed one of experimental diets to apparent satiation for 8 weeks. Dietary supplementation of MPs did not affect the growth performance, biological indices and whole body composition of fish compared to the control. The fish fed with AG diet had an increased weight gain, and specific growth rate compared to fish in SC group. Decreased level of plasma glucose was observed in fish fed diet containing MPs. Lysozyme activity was significantly increased in the fish fed AG diet compared to that of fish in PG group. These results indicate that dietary supplementation of Angelica gigas may enhance growth performance and immune responses in juvenile red lip mullet.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.56 no.1
• /
• pp.99-108
• /
• 2023

In this study, changes in biofloc-related and pathogenic bacteria in both low and high concentration biofloc breeding water planted with the halophyte (Triglochin maritimum were investigated). In the low-concentration biofloc breeding water, the ratio of bacteria related to the nitrogen cycle was initially 59.57% and, it decreased to 26.57% at the end of the experiment while other bacteria (excluding nitrogen-cycling bacteria and vibrios) increased from 38.75% to 73.43%. However, the planted experimental group maintained a relatively high ratio of nitrogen cycling bacteria at 58%. In the high-concentration experimental group, bacteria related to the initial nitrogen cycle, non-pathogenic vibrios, and pathogenic vibrios were 11.60, 36.28, and 20.14%, respectively. Finally, nitrogen-cycling bacteria were 36.47% in the control group and 37.55% in the planted group. The total number of vibrios decreased by 46.54% in the planted group and 48.01% in the control group, indicating a significant decrease in both experimental groups. However, the residual rate of pathogenic vibrios was 4.48% in the control group and 0.54% in the planted group. Overall, the planted group showed decreasing harmful bacteria and increasing useful bacteria.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.56 no.3
• /
• pp.347-351
• /
• 2023

Flying fish Cypselurus agoo roe is a popular food ingredient due to its abundant nutrition, unique texture, and flavor. It contains high levels of polyunsaturated fatty acids, protein, and minerals such as calcium, phosphorus, potassium, and vitamins (A, B₁, B₂, B₆, and niacin), making it a highly utilized food ingredient. Additionally, it is widely used as a raw material for food and cooking in several countries. After harvesting, flying fish roe is dried and transported to processing plants, where it performed a re-moisturizing process. However, the conventional re-moisturizing process is time-consuming and results in some loss of quality. Thus, this study investigates the conditions required for the re-moisturization of flying fish roe including the composition of the immersion solution, immersion time, and conditions that could minimize damage to the roe. The results suggest a reasonable composition of immersion solution to minimize damage to flying fish roe and the most appropriate immersion time for re-moisturization. These results may provide valuable insights for the industry to enhance the quality of re-moisturized flying fish roe, leading to an increase in its market value and demand.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.3 no.1
• /
• pp.27-37
• /
• 2000

This study aims at restoring urban forest destructed and eliminated by industrialization, urbanization, and city development and presenting a direction to manage remaining urban forest ecologically. To this end, an experiment zone where Populus tomentiglandulosa T. Lee were selective cutted and a control zone where Populus tomentiglandulosa T. Lee were kept intact were created in Chongdam Park located in Kangnam-ku, Seoul. Then, the structural changes of herbaceous plant species, the growth of targeted woody plants, and the increase of the number of insect and bird species were examined. The conclusions reached in this study are as follows. First, for the sake of ecological restoration and management of urban forest, it is good to selective cutting. Although timing, frequency, and methods may vary depending on the features and types of urban forest, the study revealed that selective cutting contributes to the restoration speed of origin vegetation and the enhancement of biodiversity including plants and insects. Second, as for the correlations of selective cutting and the appearance of plant species, the growth of origin vegetation, and insect distribution, the study showed that the impact of meteorological environment such as brightness is much greater than that of soil environment. Third, in order to manage urban forest, tramping pressure needs to be controlled efficiently. The efficient control of tramping pressure would contribute in the appearance of herbaceous plants. It would also be beneficial in promoting biodiversity of birds by removing the impact of people using routes. Fourth, in order to enhance the overall biodiversity of urban forest, diverse environment needs to be provided. In particular, it is necessary to supply water that is insufficient in urban forest. Providing habitats such as forest wetland performs an important function to amphibians and birds that require water as well as the appearance of aquatic plants and insects. Therefore, ways to introduce water efficiently should be initiated.