• Title/Summary/Keyword: 延安

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Age and Growth of Flathead Grey Mullet Mugil cephalus Collected by a Two-side Fyke Net in the Coastal Water off Taean, Korea (태안 연안에서 이각망에 의해 채집된 숭어의 연령과 성장)

  • Hong, Jimin;Yoon, Jae Seon;Lee, Tae Won
    • Korean Journal of Ichthyology
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    • v.26 no.3
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    • pp.194-201
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    • 2014

  • Age and growth of flathead grey mullet Mugil cephalus were estimated using samples collected by a two-side fyke net in the coastal water off Taean in 2008. Age was determined by examination of annuli in otoliths and total lengths at ages were back-calculated from otolth-body size relationship. Total length ranged from 239 to 605 mm and mainly between 400 and 550 mm. Observed ages ranged from 1 to 7 years old and mainly between 3 and 5 years old. Total length (L, mm) was linearly related to otolith radius (R, mm); L=15.3+87.9 R. Total lengths at the annulus formation in otolith were back-calculated by Frazer-Lee method. Estimated length at the age 1 was $316{\pm}40.6mm$ ($mean{\pm}SD$) showing a fast growth rate during the early growth stage. Total length at each age (t) showed a wide range indicating the big difference in growth rate among individuals. Growth in total length can be expressed by a Von Bertalanffy growth curve as $L_t=542[1-{\exp}\{-0.493 (t+0.769)\}]$.

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Effects of Water Temperature Inversion on the Stratification Variation in October and December in the South Sea of Korea (한국 남해에서 10월과 12월의 수온역전현상이 성층변동에 미치는 영향)

  • Lee, Chung-Il;Koo, Do-Hyung
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.15 no.3
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    • pp.165-171
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    • 2009

  • In order to illustrate the effects of water temperature inversion on the stratification variation in the South Sea of Korea, water temperature, salinity, and density measured in October and December 1999 by National Fisheries Research and Development Institute were reviewed. In October and December of 1999, temperature inversion occurred mainly between 25m and 75m, and in particular in depth of water, in December temperature inversion layer also was formed in the surface layer. In case of October and December, the Tsushima Warm Current (TWC), warm and saline water, was one of motors, and in December, influence of surface cold water was added Although northerly wind prevails in October and December, in October, expanding of the South Korean Coastal Waters (SKCW) towards offshore is not clear, but in December when wind speed is relatively greater than that in October and strength of the TWC become weak, the SKCW spreads towards offshore through the upper layer. Stratification variation was higher along the area where temperature inversion occurred.

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