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

• Korean Journal of Ichthyology
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• v.17 no.1
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• pp.8-18
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• 2005

A total of 33 fish species were collected by a small beam trawl from an eelgrass bed in Myoungjuri of Jindong Bay, Korea. The dominant fish species were Hexagrammos otakii, Pholis fangi, Repomucenus valenciennei, Pseudoblennus cottoides, Pholis nebulosa, Rudarius ercodes, Syngnathus schlegeli, and Sebastes schlegeli. These 8 fish species accounted for 79.5% of the total number of individuals collected. The fishes collected in the study area were primarily small fish species or juveniles of large fish species. Seasonal variations in both species composition and abundance were large; higher numbers of fish occurred from April to June 2002, while biomass was the highest in September 2001 and 2002. Seasonal changes in fish abundance corresponded with eelgrass biomass and abundance of food organisms.

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.505-515
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• 2015

The objectives of this study were to determine the effects of stream nutrient regime, N:P ratios and suspended solids on fish tolerance/trophic compositions and stream ecosystem health, based on multi-metric model, during 2008-2013. Also, stream ecosystem health was evaluated in relation to chlorophyll-a (CHL) as a measure of algal productivity or indicators of trophic state to water chemical parameters. Total number of sampled fish species were 50 and showed a decreasing trend from 2008 to 2013. The minnow of Zacco platypus, based on the catch per unit effort (CPUE), was the most dominant species (25.9%) among the all species. Spatial heterogeneity was evident in the fish tolerance guilds that showed the dominance of sensitive species (89%) in the headwaters (S1) and the dominance of tolerant species (57%) in the urban. These conditions were directly influenced by concentrations of nutrients and organic matter (COD). The N:P ratios, as a barometer of water pollution, had a negative linear function (R² = 0.40, P < 0.01) with CHL, and the ratios had an important role in changes of COD concentration (R² = 0.40, P < 0.01). Under the circumstances, the N:P ratio directly influenced the relative proportions of fish trophic/tolerance compositions. According to the regression analysis of omnivore (O_m) and insectivore sp. (I_n) on total nitrogen and total phosphorus, nitrogen had no significant influences (P > 0.05) to the two compositions, but phosphorus influenced directly the two guilds [slope (a) = -32.3, R² = 0.25, P < 0.01 in the I_n; a = 40.7, R² = 0.19, P < 0.01 in the O_m]. Such water chemistry and fish trophic guilds determined the stream ecosystem health, based on the multi-metric fish model.

• Journal of fish pathology
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• v.18 no.2
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• pp.105-118
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• 2005

Anemia in fish can be easily recognized by examining the gill color and physical properties of sampled blood. The number of erythrocytes is generally within 1-3 ${\times}10^6$. Hematocrit (Ht) reportedly ranges 35-45% in many of reports which is nearly the same as that in mammals. Anemia in fish can also be classified as hemorrhagic, hemolytic and hypoplastic ones. Fish are also expected to have similar pathological effects by anemia as in mammals. From the fact that fish can survive under extremely low hematocrit below 10% and antarctic icefish (Chanenocephalus aceratus) has no erythrocytes, different pathological effects were expected. Anemia is considered to have one of the most important health parameters, based on the pathological aspect. Therefore, by reviewing clinical and histopathological findings of most of fish diseases already known and then adding our results of experimental anemia, diseases and factors related to anemia were summarized and the pathological effects was discussed.

• Journal of Environmental Health Sciences
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• v.41 no.3
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• pp.147-162
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• 2015

Objectives: The objective of this review was to summarize the primary role of three representative endocrine axes in aquatic vertebrates and discuss the effects on endocrine systems and their interactions in teleost fish after exposure to environmental contaminants. Methods: We summarized individual traits and mechanisms for hormonal and transcriptional interactions between the hypothalamic-pituitary-gonad (HPG), hypothalamic-pituitary-thyroid (HPT), and hypothalamic-pituitary-adrenal (HPA) axes in fish. We also provided a brief discussion on the effects of nonylphenol-induced toxicity on endocrine systems and their interactions in fish as a demonstration of holistic explanation. Results: Currently-available data showed that thyroid dysfunction is associated with reproductive toxicity due to changes in steroidogenic gene expressions and sex hormone levels as well as gonad glands in fish. As an example, we demonstrated that exposure to nonylphenol could induce estrogenicity in male fish by decreasing thyroid hormones, which contributes to increased aromatase expression. Although the mechanisms are complicated and involved in multiple ways, a number of studies have shown that sex steroids influence the HPT axis or the HPA axis in fish, indicating bi-directional crosstalk. Critically missing is information on the primary target or toxicity mechanisms of environmental contaminants among the three endocrine axes, so further studies are needed to explore those possibilities. Conclusions: This review highlights the interactions between the HPG, HPT, and HPA axes in fish in order to better understand how these endocrine systems could interact with each other in situations of exposure to endocrine disrupting chemicals.

• Journal of fish pathology
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• v.30 no.1
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• pp.25-39
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• 2017

A total number of 668 apparently healthy fish were obtained from farm to study the effect of two heavy metals in a form of (Copper sulfate and Mercuric chloride) on some hematological and biochemical parameters of blood. The $LC_{50}$ /96 hr. of Cu and Hg were estimated and fish exposed to $\text\tiny{^1/_2}$ $LC_{50}$ for 7 days and for $1/_{10}$ $LC_{50}$ for 8 weeks from each product separately. Results showed decrease in RBCs count, PCV% and Hb in acute and chronic mercury while a significant increase was shown in acute and chronic copper toxicity, total leucocytic count showed decrease in acute mercury toxicity and increase in the chronic case, while in copper toxicity non-significant decrease in acute and significant decrease in chronic toxicity was noticed. Elevated serum urea and creatinine in both acute and chronic mercury and copper toxicity was detected. No changes in total bilirubin in the acute mercury and chronic copper toxicity while significant increase in chronic mercury and acute copper. Elevation of serum AST and ALT in some days of acute toxicity of mercury and copper while in chronic mercury toxicity a significant elevation of both serums AST and ALT were detected .while in chronic copper toxicity serum AST was fluctuated and ALT showed no significant changes. CK study revealed significant decrease in acute mercury with fluctuation in the chronic toxicity while in copper toxicity it showed fluctuation in acute and significant decrease in chronic toxicity. Glucose value decreased in acute and chronic mercury toxicity while in copper toxicity it showed significant increase in the acute and increase followed by significant decrease in the chronic copper toxicity.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.8
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• pp.2278-2291
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• 2023

Imported ornamental fish should be quarantined because they can have dangerous diseases depending on their habitat. The quarantine requires a lot of time because quarantine officers collect various information on the imported ornamental fish. Inefficient quarantine processes reduce its work efficiency and accuracy. Also, long-time quarantine causes the death of environmentally sensitive ornamental fish and huge financial losses. To improve existing quarantine systems, information on ornamental fish was collected and structured, and a server was established to develop quarantine performance support software equipped with a text search engine. However, the long names of ornamental fish in general can cause many typos and time bottlenecks when we type search words for the target fish information. Therefore, we need a technique that can correct typos. Typical typo character calibration compares input text with all characters in a calibrated candidate text dictionary. However, this approach requires computational power proportional to the number of typos, resulting in slow processing time and low calibration accuracy performance. Therefore, to improve the calibration accuracy of characters, we propose a fusion system of simple Artificial Neural Network (ANN) models and character preprocessing methods that accelerate the process by minimizing the computation of the models. We also propose a typo character generation method used for training the ANN models. Simulation results show that the proposed typo character correction system is about 6 times faster than the conventional method and has 10% higher accuracy.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.601-605
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• 2009

Due to the fact that fish-eye lens can provide super wide angles with the minimum number of cameras, field-of-view over 180 degrees, many vehicles are attempting to mount the camera system. Camera calibration should be preceded, and geometrical correction on the radial distortion is needed to provide the images for the driver's assistance. However, vehicle fish-eye cameras have diagonal output images rather than circular images and have asymmetric distortion beyond the horizontal angle. In this paper, we introduce a camera model and metric calibration method for vehicle cameras which uses feature points of the image. And undistort the input image through a perspective projection, where straight lines should appear straight. The method fitted vehicle fish-eye lens with different field of views.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.5
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• pp.645-653
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• 2014

We examined seasonal variation in fish species composition in coastal waters near Wolseong Nuclear Power Plant in the East Sea of Korea. A total of 72 species, 39 families, 14 orders, 46,214 individuals, and 4,639,667 g were collected. Glyptocephalus stelleri was the most dominant species by number of individuals (35%), followed by Clupea pallasii (26%). Liparis tanakai and Lophius litulon were the dominant species by biomass, accounting for 46% and 28%, respectively. We showed that bottom salinity and temperature are the most important environmental factors influencing fish species composition. Although bottom salinity did not differ statistically among seasons or stations, we detected some variation among stations. Additionally, bottom temperature differed among seasons and stations (P<0.05), affecting numbers of individuals and biomass. Thus, seasonal variation in fish assemblages can be classified into two groups: spring/summer and autumn/winter.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.1
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• pp.253-261
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• 2015

The chemical water quality and fish assemblage of Dong Stream to assessment of environmental improvement after discharge seawater were investigated from July to December 2013. BOD and DO were significantly different between before and after discharge seawater, while pH and SS did not significant. A total of 11 fish species, 218 individuals and 10,525.1g were collected. Dominant fish species were Mugil cephalus, Konosirus punctatus, Acanthogobius flavimanus and Leiognathus nuchalis which account for 77.5% of total individuals collected, and they were estuarian species. Peak number of species and individuals, and biomass occurred in September, whereas diversity index were highest in November. The water ecosystem of Dong Stream have been changed estuarian environment. As a result of stream assessment on water quality and ecosystem, water quality have been improved as 'III' grade. These results suggested that stream restoration policies such as drain pipes maintenance, management of pollution sources and riverbed dredging to improve environment and recover habitate of Dong Stream were need for set up and establishment of regular monitoring system.