Study of Hydrological Environmental Factors' Influence on Lizardfishes Resources Change in the South-Western Waters Off Taiwan

臺灣西南海域海洋水文環境與狗母魚資源變動研究

賴繼昌(Chi-Chang Lai) ； 楊清閔(Ching-Min Yang) ； 何珈欣(Jia-Sin He) ； 吳龍靜(Long-Jing Wu) ； 呂學榮(Hsueh-Jung Lu)

《臺灣水產學會刊》 40卷2期 (2013/06) Pp. 89-106

https://doi.org/10.29822/JFST.201306_40(2).0002

摘要

過去臺灣對於沿近海表中層洄游性魚類在氣候變遷的影響下，漁場遷移與資源量變動的研究已經有相當豐富的研究成果，但對於底棲性魚種受氣候變遷的影響則少有著墨。本研究以廣泛運於水產加工產品的底棲性的魚種－狗母魚為對象，探討1997－2012年共16年間狗母魚在棲地水文環境因子的變動下，其資源量變動情形。根據結果顯示，臺灣西南海域漁場以花斑蛇鯔（Saurida undosquamis）為最主要的狗母魚漁獲種類，比對水溫、漁期、產卵盛期、漁獲量、CPUE、食性與地理資訊，可知於1－3月份產卵盛期後往較淺之溫暖水域遷移，9月份起再回到較深之水域。而氣候變遷指數SOI、PDO、MEI、棲息深度的溫、鹽因子與狗母魚的資源量變動具有相關性，海表面溫、鹽因子與河川排水量則與狗母魚資源量不相關。由各項氣候變遷因子的變動可知，在氣候變遷指數傾向於反聖嬰現象發生時，有助於狗母魚CPUE的上升，100m水深的溫度變動與CPUE呈現正相關，與鹽度變動成呈現負相關。推測反聖嬰現象帶來強東北季風有利於垂直水層混合，且營養鹽相對高於黑潮水的南海海水經由澎湖水道湧入，促進狗母魚資源量增加。突發性的水文環境變動－颱風，亦會造成狗母魚資源量的增加。本研究結果有利於未來在水文環境因子變動的影響下對於此種底棲性水產糧食資源的掌握，預測其變動，並作為因應策略擬定之重要參考依據。

關鍵字

水文環境 ； 狗母魚 ； 底拖網 ； 南方震盪指數

並列摘要

A lot of studies have been done on the fishing grounds shift and resources of surface and mid-layer migratory fishes near Taiwan, but less were done on the bottom dwelling fish species. In this research, the bottom dwelling lizardfishes commonly used for processed seafood products were studied to understand the shift of its resources during the 15 year period between 1997 and 2011, under the climate change index and environment factors of its habitat.Results show Saurida undosquamis is the main lizardfish species caught in the south-western waters of Taiwan. Comparing water temperature, fishing season, spawning peak, landing, CPUE, feeding habits and geographic information, we found it moves to the warmer shallow waters after spawning peak during Jan. - Mar., and return after September. Climate change index, SOI, PDO, MEI, temperature and salinity factor at depth are relevant to the shift in its resources, but not sea surface temperature, salinity and river drainage. Judging from the variation of these climate change factors, the occurrence of La Niña raises the CPUE of lizardfishes, with a positive correlation with temperature change and a negative correlation with salinity respectively at the depth of 100 m. These facts suggest that the strong northeast monsoon that La Niña brings is conducive to the vertical mixing of different water layers. Furthermore, water from the South China Sea, carrying more nutrient than the Kuroshio Current, flows through the Penghu Channel also contributes to the increase in lizardfishes resources. Sudden changes in the hydrological environment such as typhoons, may result in the increase of lizardfishes resources as well.This research will help to predict changes in the lizardfish resources under the influence of hydrological environment changes which provide an important reference for making responsive strategies in the future.

並列關鍵字

Hydrological Environment ； lizardfishes ； Bottom Trawlnet ； SOI