• 대한조선학회논문집
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• 제61권3호
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• pp.185-199
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• 2024

Global warming impacts every corner of human life. Maritime transportation and shipbuilding industries are no exception. Recent counteraction in maritime industries is accelerating to meet the zero emission by 2050. Various alternative energy sources have been studied, and recent developments in Europe show that the windship, as a proven technology, can be an attractive candidate to solve the problem. In this paper, as the alternative transportation option, to infer the performances of modern windships, the non-dimensional ratios of past tall ships and windships are studied and reviewed. In addition, the ratios are compared to estimate the position of current and future windships under consideration. It is found that regarding the ratio distributions, the current windships being planned can be either wind-assisted propulsion ships or less fully functional windships than the past tall ships.

• 한국수산과학회지
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• 제40권2호
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• pp.84-94
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• 2007

The comparative feeding ecology of greenling Hexagrammos otakii and Schlegel's black rockfish Sebastes schlereli populations was investigated in the Jangbong tidal flat near Incheon, Korea. Monthly samples were taken using a modified otter trawl from November 1999 to January 2001. The stomach contents of 124 greenling and 115 Schlegel's black rockfish were analyzed. The diet of H. otakii was dominated by the amphipods Gammaropsis iaponicus, Caprella scaura, Isaeopsis sp. and Monocorophium acherusicum, the shrimps Latreutes mucronatus and Alpheus japonicus, the mysid Neomysis orientalis and the bivalve Mytilus edulis. In contrast, S. schlegeli mainly fed on the mysids N. orientalis, N japonica, and N. awatschensis, the shrimps Exopalaemon carinicauda, A. japonicus and L. mucronatus, and the fish Pholis fangi and unidentified gobiids. A comparison of the frequency and abundance of food items showed that crustaceans (e.g. amphipods, mysids and shrimps) were important foods for both species. Their main dietary components, however differed which is probably due to differences in the spatial distribution of the two species and their prey items. In conclusion, greenling and Schlegel's black rockfish, despite being sympatric on a tidal flat have distinct food habits and low dietary overlap (Schooner's index: 0.1). These results indicate, to some extent, resource partitioning for the maximum utilization of available foods in the tidal flat.

• Fisheries and Aquatic Sciences
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• 제26권8호
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• pp.482-490
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• 2023

Food and feeding habits of Labeobarbus intermedius were studied from the newly constructed Ribb Reservoir, Ethiopia during the dry (December-March) season and wet season (June-August) of 2021. The objective of the study was to determine the diet composition, seasonal variation, and ontogenetic dietary shift in the diets of the dominant cyprinid fish in Ribb Reservoir. In this study, frequency of occurrence and volumetric analysis methods were used to present the results. From a total of 203 fish samples, 132 (65%) guts contained food items. Macrophytes (29.4%), phytoplankton (27.2%), detritus (14.8%), and insects (13.6%) were the major food items in the diets volumetrically. During the dry season, L. intermedius was mainly dependent on phytoplankton (58.2%), insects (15.2%), and zooplankton (13.7%) volumetrically. Whereas, macrophytes (50.3%) and detritus (23.3%) were the dominant food items in the wet season. The frequency occurrence and volumetric contribution of the diets of L. intermedius varied significantly (χ² test, p < 0.05) between seasons. Schoener's diet overlap index revealed a slight ontogenetic dietary shift in the diets of L. intermedius. While insects, nematodes, and zooplankton were the main diets of small-sized L. intermedius, macrophytes and detritus were ingested by large-sized L. intermedius. Generally, L. intermedius fed both plant and animal-origin food items and is considered an omnivorous feeder in Ribb Reservoir.