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나로도 주변해역의 어장학적 특성 (2) -수괴의계절변화 -

The Characteristics of Fishing Ground in the Adjacent Sea of Naro Island (2) - Seasonal Variation of Watermass -

  • 발행 : 2003.02.01

초록

한국 남해 연안 해역인 나로도 주변 어장에서 동계, 춘계, 하계 및 추계에 조사한 해양 관측 자료를 이용하여, 이 어장에서의 수괴 특성을 분석한 결과를 요약하면 다음과 같다. 1) 나로도 주변 어장에서 수온과 염분의 측정값을 이용한 T-S diagram으로부터 염분을 기준으로 수괴를 구분하였다. 연안수는 30.0∼31.4psu, 혼합수는 31.5∼32.9psu, 외해수 33.0∼35.0psu의 범위로 정하였다. 2) 나로도 주변 어장에 출현하는 동계의 염분 분포범위는 33.1∼34.9psu, 춘계는 33.1∼34.3psu, 하계는 30.5∼34.1psu, 추계는 30.1∼34.0psu의 범위이었다. 3) 나로도 주변 어장에 출현한 연안수, 혼합수 및 외해수의 분포 특성을 계절별로 파악할 수 있었다. 동계와 춘계에는 표층에서 저층까지의 전해역이 외해수로 점유되었다. 하계에는 표층의 전 해역이 혼합수로 점유되지만, 저층에는 혼합수와 외해수로 형성된다. 추계에는 표층에 연안수와 혼합수가 분포하고 있으며, 저층에는 혼합수가 주체를 이루고 있으나 연안역에 국한되어 연안수가 분포하고, 외양으로 외해수가 출현하기 시작한다. 4) 나로도 주변 어장의 수온염분 특성은 계절적으로 변화하여, 동계에는 저온고염의 외해수가 분포하고, 춘계에는 동계의 수괴의 특성을 유지하지만, 수온이 다소 증가한다. 하계에는 고온 저염의 혼합수와 외해수가 분포하고, 추계에는 저온의 연안수, 혼합수 및 외해수가 분포한다. 5) 수온과 염분의 변화가 주로 표층과 20m층 사이에서 이루어져 하계에는 수온이 4.$0\circ_C$/7m의 수직경도를 보였으며, 춘계와 추계에는 수온과 염분의 변화는 적고, 동계에는 연직 혼합이 일어나 상하층간에 균질한 해수가 분포하였다.

In order to investigate the seasonal variation of watermass in the adjacent sea of Naro Island, oceanographic observation on the fishing grounds were carried out by the training vessel of Yosu National University on winter, spring, summer, and autumn in 2000. The results obtained are summarized as follows ; 1) the watermass in the fishing ground were divided into the coastal water (30.0∼31.4psu), mixing water (31.5∼32.9psu) and the offshore water (33.0∼35.0psu) according to the distribution of salinity from T-S diagram plotted all salinity data observed on winter, spring, summer, and autumn in 2000. 2) the ranges of temperature and salinity were from 4.$3\circ_C$ to 10.1$^{\circ}C$ and from 33.1psu to 34.9psu in winter, from 8.$1\circ_C$ to 13.$7\circ_C$ and from 33.1psu to 34.3psu in spring, from 14.5$^{\circ}C$ to 24.$2\circ_C$ and from 30.5psu to 34.1psu in summer, and from 14.$5\circ_C$ to 18.$6\circ_C$ and from 30.1psu to 34.0psu in autumn, respectively. 3) the distribution of watermass in the fishing ground varied largely each seasons, but a general tendency on the distribution was obtained. That is, in winter and spring the offshore water was distributed most widely and in summer the coastal and mixing water occupied the fishing ground but in autumn the mixing water prevailed. 4) variation of temperature and salinity were appeared between the surface and 20m layer in the sea aduacent to Naro Island. Therefore, in the summer the thermocline were made between surface and 20m layer with vertical gradients of 4.$0\circ_C$/7m.

키워드

참고문헌

  1. An, H. S. and Oh, J. S. (1984) : A comparative analysis of the water masses in the East China Sea in summer and winter, J. Korean Earth Sci. Soc., 5(1), 33-44 (in Korean).
  2. Cho, K. D. and Kim, H. Y. (2000) : Relationship between the distribution of water masses and that of demersal fish in the East China Sea in spring. J. Fish. Sci. Tech., 3(1), 14-22.
  3. Cho, K. D. and Yang, Y. R (1985) : Environment of the purse-seiner fishing ground in the Tsushima Current, Bull. Korean Fish. Tech. Soc., 21(1), 41-61 (in Korean).
  4. Choo, H. S. (2002) : The variations of oceanic conditions and the distributions of eggs and larvae of anchovy in the southern sea of Korea in summer, J. Korean Fish. Soc., 35 (1), 77-85 (in Korean). https://doi.org/10.5657/kfas.2002.35.1.077
  5. Hwang, D. J., Shin, H. H., and Kim, D. S. (1999) : Distribution of fish by echo sounder and environment of oceanography in southern sea of Korea, Bull. Korean Soc. Fish. Tech., 35 (2), 170-176 (in Korean).
  6. Kang, C. J. (1974) : A study on the seasonal variation of the water masses in the southern sea of Korea, Bull. Fish. Res. Dev. Agency, 12, 107-121 (in Korean).
  7. Kim, D. S (2000) : Seasonal variation of watermass in the central coast of the southern sea of Korea, Bull. Korean Soc. Fish. Tech., 36(2), 105-116 (in Korean).
  8. Kim, D. S. and Rho, H K (1996) : Environmental factors and catch fluctuation of set net grounds in the coastal water of Yosu. 4. Water temperature and salinity and catch fluctuation, Bull. Korean Soc. Fish. Tech., 32(2), 125-131 (in Korean).
  9. Kim, I. O. and Rho, H. K. (1994) : A study on China Coastal Water appeared in the neighbouring seas of Cheju Island, Bull. Korean Fish. Soc., 27(5), 515-528 (in Korean).
  10. Lee, M. O. (1994) : Numerical model experiments on the tidal current variations due to the bridge piers construction near the straits of Narodo Islands, Bull. Korean Fish. Soc., 27(1), 47-58 (in Korean).
  11. Lim, K. B. (1981) : Oceanographic conditions in the southern water of Korea and characteristics of fishing ground of pacific mackerel, Bull. Fish. Res. Dev. Agency, 27, 7-24 (in Korean).
  12. Nakata, H. (1991) : Coastal processes related to the transport, survival and recruitment of fish larvae, Bull. on Coastal Oceanography, 28 (2) , 195-220 (in Japanese).
  13. Park, J. H and Choi, K. H. (1995) : A study on the formation of fishing ground and the prediction of fishing conditions mackerel, Scomber Japonicus Houttuyn, Bull. Fish. Res. Dev. Agency, 49, 25-35 (in Korean).
  14. Park, J. S. and Lee, S. G. (1990a) : Distribution and species composition of phytoplankton in the southern waters of Korea and their relation to the character of water masses, Bull. Korean Fish. Soc., 23 (3), 208-214 (in Korean).
  15. Park, J. S., Lee, S. S., Kang Y. S., Lee, B. D. and Huh, S. H. (1990b) : The distributions of copepods and chaetognaths in the southern waters of Korea and their relationship to the characteristics of water masses, Bull. Korean Fish. Soc., 23 (3), 245-252 (in Korean).
  16. Ricker, W. E. (1954) : Stock and Recruitment. J. Fish. Res. Board Can., 11 (5), 559-623. https://doi.org/10.1139/f54-039
  17. Shin, H. R. (1994) : Analysis of seasonal distribution of water mass in the Korea Strait and the East China Sea, J. Korean Earth Sci. Soc., 15(2), 81-90 (in Korean).
  18. Yang, J. Y, Kim, S. H. and Rho, H. K. (1998) : A study on the temperature fronts observed in the south-west sea of Korea and the northern area of the East China Sea, J. Korean Fish. Soc., 31 (5), 695-706 (in Korean).