• Ecology and Resilient Infrastructure
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• v.11 no.1
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• pp.11-22
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• 2024

A fishway is an artificial waterway or device used to resolve difficulties in the movement of fish in a river. Most existing fishways are made of concrete and emit toxic substances, which has a negative impact on the river environment. Accordingly, there is a need to develop fishway construction technology that is eco-friendly and can increase movement efficiency. The technology presented in this study is an integrated porous structure that combines the aggregate with a biopolymer material extracted from castor oil, a non-toxic material. It is a fishway construction technology using eco-friendly materials that can allow vegetation to grow on the surface. In this study, an eco-friendly fishway mixed with biopolymer and aggregate was built on a real scale and the fish movement efficiency was tested and analyzed. As a result of the experiment, a total of 201 fish of 14 species were released with tags inserted, and the detection rate of released fish was confirmed to be 82.6% on average. A total of 40 fish of 6 species were transported upstream through the fishway, and the average passage rate was confirmed to be 21.7%. As a result of checking the circadian migration pattern, it was found that all fish mainly migrate during the day. It was confirmed that there was no significant functional difference between a fishway using biopolymer and a concrete fishway. It is believed that a fishway using biopolymer can be used as a replacement for a concrete fishway.

• Journal of Environmental Science International
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• v.23 no.8
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• pp.1513-1522
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• 2014

Fish passage asssessments were conducted in the fishway at Juksan Weir, which was constructed as a four-major rivers project in the downstream area of Youngsan-River Watershed. For the research, fish-movements/migrations were analyzed for seven times from April ~ October, 2013 using an approach of fish trap-setting. Fish fauna and compositions were analyzed in the fishway, and seasonal- and diel-movement patterns were analyzed in relation to current velocity in the fishway. Also, abundances of exotic fishes such as bluegill sunfish (Lepomis macrochirus), large-mouth bass (Micropterus salmoides), and white curcian carp (Carassius cuvieri) were monitored in the fishway. Current velocity(n = 18) in the fishway showed large variations ($0.82{\pm}0.63m/s$) depending on the location of the fish trap-setting and this physical factor influenced the fish movements. Fish movements, based on the CPUE of individuals, in the fishway was greater in slower velocity (mean: 0.36 m/s, range: 0.10~1.54 m/s) than faster velocity (mean: 1.51 m/s, range: 0.90~1.90 m/s). Seasonal analysis of fish movements showed that most frequent uses (8 speices and 591 individuals, 66.2% of the total) of the fishway occurred in spring period(i.e., June). Diel movement analysis, in the mean time, showed highest in the time period of 00:00 ~ 3:00 am (7 species and 281 individuals, 20.9% of the total). The efficient managements in the fishway at Juksan Weir are required in relation to the hydrological regime.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.1
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• pp.29-38
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• 2019

In order to investigate the behavioral characteristics of Pacific cod (Gadus macrocephalus) released at the entrance of Jinhae Bay, Korea, the direction and range of movement, swimming speed of the fish were measured with an acoustic telemetry techniques in winter, 2015. Three wild Pacific codes WC1 to WC3 (total length 66.0, 75.0, 76.0 cm; body weight 2.84, 2.79, 3.47 kg, respectively) were tagged with the acoustic transmitter. WC1 tagged with an acoustic transmitter internally by surgical method, WC2 and WC3, externally with the acoustic data logger and a micro data logger for recording audible sound waves including timer release unit. The movement routes of the tagged fish were measured more than five hours using VR100 receiver and a directional hydrophone. The directionality of the fish movement was tested by Rayleigh's z-Test, the statistical analysis, and a statistical program SPSS. Three tagged fishes were individually released on the sea surface around the entrance to the Jinhae Bay on 10 to 24 January 2015. WC1 moved about 13.32 km with average swimming speed of 0.63 m/s for six hours. The average swimming depth and water depth of the seabed on the route of WC1 were 7.2 and 32.9 m, respectively. The movement range of WC2 and WC3 were 7.95 and 11.06 km, approximately, with average swimming speed of 0.44 and 0.58 m/s for 5.1 and 5.3 hours, respectively. The average swimming depth of WC2 and WC3 were 18.7 and 5.0 m, and the water depth on the route, 34.4 and 29.8 m, respectively. Three fishes WC1 to WC3 were shown significant directionality in the movement (p < 0.05). Movement mean angles of WC1 to WC3 were 77.7, 76.3 and $88.1^{\circ}$, respectively. There was no significant correlation between the movement direction of fish (WC1 and WC2) and the tidal currents during the experimental period (p >= 0.05). Consequently, three tagged fishes were commonly moved toward outside of the entrance and headed for eastward of the Korean Peninsula, approximately, after release. It may estimate positively that the tidal current speed may affect to the swimming speed of the Pacific cod during the spring tide than the neap tide.

• Environmental Analysis Health and Toxicology
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• v.14 no.4
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• pp.217-222
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• 1999

Changes in certain fish behaviors are known to be very sensitive indicators of sublethal exposure to environmental contaminants. Therefore, behavioral toxicity tests, if properly designed, can be very useful to assess the influence of hazardous chemicals on fish. However, quantitative analysis of xenobiotic-mediated changes in locomotor behavior in fishes are rare, due mainly to the methodological difficulties. In general, fish movement has been known to be hypertrophic or hypotrophic according to the chemicals. As a study of fish behavioral toxicities, we qualified the swimming movement of Oryzias latipes using computer-automated video tracking system. Oryzias latipes was exposed to cadmium of 128 mg/L for 1 hour in a limited aquaria, then the total swimming distance, the average swimming velocity, the histogram of turning angles, and the turning frequency were analyzed. Fish treated with cadmium showed decreased swimming activities, decreased velocity, and decreased turning frequency, which means hypotrophic activity. From these results, the computer-automated video tracking system of this study seems to be a good tool for the evaluation of the potential ecotoxicological studies.

• Fisheries and Aquatic Sciences
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• v.24 no.1
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• pp.32-40
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• 2021

Monitoring fish movement is important to understand how physiology adapts to environmental change. To explore the applicability of a video tracking system for determining if chemical cues attract or repel aquatic animals, the movement patterns of rock bream, Oplegnathus fasciatus, were analyzed upon exposure to various materials, including extracts of sea urchin, rock worm, bait worm, krill, barley kernel, and commercial fish feed. Pellets were prepared by mixing freeze-dried tissues with a cellulose and corn flour mixture. Behavioral analysis was carried out with five fish that had been acclimated in the adaptation zone of a Y-shaped tank. Preference toward chemical cues was quantified by assessing the frequency rock bream were observed in a discrete zone around the test material located at the end of each arm and the duration each fish stayed in each zone. The analysis of fish movement upon exposure to commercial feed and barley kernel at each end, respectively, indicated a clear preference toward the feed relative to the barley kernel. Movement responses were further tested with pellets containing extracts of sea urchin, one of the species collected on a large scale, and other materials including krill and worms. A stronger preference toward sea urchin (100%) was observed based on the duration of stay in the test zone, compared to krill (90.1 ± 44.2%), bait worm (81.1 ± 39.1%), rock worm (73.7 ± 28.9%), and barley (63.9 ± 25.9%), under the conditions tested. A detailed comparison of rock bream movements toward each material revealed significant differences in frequency and duration, respectively, between pairs of test materials including krill (74 ± 29.8 and 375.6 ± 118.9) vs. rock worm (41.5 ± 18.7 and 160.2 ± 42.6), krill (86.3 ± 22.9 and 477.1 ± 84) vs. bait worm (36.2 ± 5.5 and 166.1 ± 50.7), and rock worm (45.9 ± 26.2 and 213.7 ± 100.1) vs. bait worm (34.6 ± 21.7 and 159.5 ± 98.5). Rock bream exhibited preference for the test materials in the following order: commercial fish feed > sea urchin > krill > rock worm > bait worm > barley. The results suggest a higher potency of sea urchin extract as a rock bream fishing bait compared to the other materials that are used as commercial bait.

• Korean Journal of Ecology and Environment
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• v.46 no.2
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• pp.154-165
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• 2013

The species composition of the fish community was studied in four streams where fish kills have previously occurred in recent years; Worun Stream, Seo Stream, Jangnam Stream, and the Anyang Stream. The number of fish species varied from 22 to 86% compared to the number of fish species pre-fish kill. The recovery of fish populations in the streams seems to be determined by water quality and the presence of artificial structures in the streams. The Jangnam Stream, where alkaline pH caused a fish kill, showed a high recovery of fish species due to improvements in water quality. Anyang Stream had a low number of species, possibly because dissolved oxygen concentrations were intermittently low. Artificial structures in streams had a negative impact the recovery of fish species, particularly for benthic fish species. It appears that fish populations can recover rapidly when water quality improves or the movement of fish community is unimpeded. However, water quality and artificial structures in many streams in Korea still present adverse conditions for fish survival, deterring the recovery of fish populations. To conserve fish populations in streams, habitat all owing unimpeded movement for fish and controls on pollutant inputs are needed.

• Journal of Korean Society of Forest Science
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• v.108 no.2
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• pp.224-232
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• 2019

The movement of fish to the upper and the lower parts of a mountain stream was investigated based on the installation of specific types of structures within the stream. The results indicated that as the flow rate increases after a rain, the height of the drop in an open-type structure, such as a concrete box, is decreased so that the floating fishes, such as the Chinese minnow fish, move relatively easily from the upper to the lower parts and from the lower to the upper parts of the stream. In contrast, the fishes released from an upper point of a wall-type structure with <1 m, such as rocks drop works and stone masonry for stream-grade stabilization, were trapped in the lower part of the stream and, even after the rainy season, it was difficult for the fish to move from the lower to the upper parts of the stream. In particular, the barrier-type structures ${\geq}3m$ limit the movement of fish, even when there are few drainage holes at the lower end of the dam, and there is no space for the fishes to communicate with each other, even when the flow rate is high; therefore, although the fish are active, they are restricted to move according to the type and characteristics of the structures. When installing structures in a mountain stream, the height of the structure must be low enough to allow the fish to communicate with each other or an open-type structure must be installed. The fish habitat and water conditions within the stream must be considered when designing the type and height of the in-stream structures.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.6
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• pp.929-935
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• 1997

The total energy of fish movement and the maximum burst swimming speed were estimated and formulated in accordance with body length and water temperature for several species in fisheries by empirical methods and also by using published results. Under the assumption of swimming energy reserve of a fish at the initial rest state, the swimming endurance of fish with different body lengths, swimming speeds and angular velocity was calculated using the relevant equations under similar conditions in tank experiments as well as natural conditions in field. Relative swimming energy efficiency or the transition swimming speed between red and white muscle for energy consumption was represented as a trigonometric function of swimming speed ratio. Therefore, this model does closely approach the actual swimming abilities and their limits especially in relation to the fishing gear operation and allow for the greater vitality of the wild fish in the fields.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2002.10a
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• pp.156-156
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• 2002

The goal of this study is to develop a biomarker used in monitoring abnormal behaviors of Japanese medaka (Oryzias latipes) as a model organism caused by hazardous chemicals that are toxic and persistent in the ecosystem. A widely used insecticide, diazinon (O, O-diethyl O- (2-isopropyl-4-methyl-6-pyrimidinyl) phosphorothioate), is highly neurotoxic to fish, and it is also well known that it causes vertebral malformation and behavioral changes of fish at relatively low concentrations. The fish behaviors were observed on a real time basis using an image processing and automatic data acquisition system. The genes potentially involved in the abnormal behaviors were cloned using suppression subtractive hybridization (SSH) technique. The untreated individuals showed common behavioral characteristics. When the test fish was affected by diazinon at a concentration of 0.1 and 1 ppm, some specific patterns were observed in its behavioral activity and locomotive tracks. The typical patterns were enhanced surfacing activity, opercular movement, erratic movement, tremors and convulsions as reported previously. The number of genes up-regulated tty diazinon treatment were 97 which includes 27 of unknown genes. The number of down-regulated genes were 99 including 60 of unknown genes. These gene expression patterns will be analyzed by the artificial neural networks such as self organization map (SOM) and multilayer perceptron (MLP), revealing the role of genes responsible for the behaviors. These results may provide molecular biological and neurobehavioral bases of a biomonitoring system for diazinon using a model organism such as fish.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.29 no.4
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• pp.260-271
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• 1993

Due to depletion of fish resources as time goes on, the trawl fishing industries which have caught the demersal fish is confronting with financial difficulties. For the purpose of breaking these difficulties, trawlers are expanding the fishing targets to the midwater from bottom stock. The trawlers become to be able to detect the fish schools not only vertical but also horizontal direction by equipping the sonar system on board. Even though the operator locates the fish school by sonar, it is not easy to make a desirable catch of the fish school which is detected, for the reason of the maneuverring characteristics of trawler. For the purpose of enhancing the efficiency of a fish catch, the auther performed a series of on board experiments to investigate the maneuverablilites of midwater trawaler. The obtained results are summerized as follows: 1. The higher the RPM of main engine, the smaller the magnitude of turning circle. And it is smaller in the right than in the left turning 2. Towing speed varies irregularly under turning novenment. When the RPM of main engine being 560, 680 the angular velocities are 11.3deg/min, 22.5deg/min respectively. 3. The difference of new course distance between calculated by maneuverring indices and measured by experimental ship is high when altering course being large and towing speed low. 4. The faster the towing speed is, the shorter the new course distance becomes. When towing speed is same in right and left turning movement, the now course distance is shorter in case of right turning movement than in left. 5. It is considered to be convenient for a navigator to utilize the curves for altering course in order to steer the ship rapidly and accurately.