氣候變遷對臺灣西南海域主要經濟性魚種資源與漁場影響之研究

Abstract

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。本研究以西南海域重要的底棲性魚種-狗母魚及大眼鯛為對象，探討1997-2013年共17年間魚種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，大棘大眼鯛 (Priacanthus macracanthus) 為最主要的大眼鯛科漁獲種類，狗母魚及大眼鯛漁場主要以深度100 m – 200 m處CPUE較高。而由氣候變遷指數與狗母魚及大眼鯛的資源量變動關係可知，在反聖嬰現象發生時，有助於狗母魚及大眼鯛CPUE的上升，100 m水深的溫度變動與狗母魚CPUE呈現正相關，與鹽度變動則與兩魚種資源量呈現負相關。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，促進狗母魚及大眼鯛資源量增加。 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。 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 important bottom dwelling Red bigeye fish were studied to understand the shift of its resources during the 17 year period between 1997 and 2013, under the climate change index and environment factors of its habitat. Results show Saurida undosquamis was the main species of the Lizardfishes, and Priacanthus macracanthus was the main species of the Red bigeye fishes caught in the south-western waters of Taiwan. The CPUE in fishing grounds was significantly higher at the depth of 100–200 m. Judging from the variation of these climate change factors, the occurrence of La Niña raises the CPUE of Lizardfishes and Red bigeye fishes, with a positive correlation with temperature change, and a negative correlation with salinity at the depth of 100 m. This suggests that the strong northeast monsoon that La Niña brings was conducive to the vertical mixing of different water layers. Further more, water from the south China sea, more nutrient than the Kuroshio, comes through the Penghu Channel influx also contributes to the increase in lizardfishes and Red bigeye fishes resources. This research will help predict changes in the lizardfish resources under the influence of hydrological environment changes and will be critical information for making coping strategies.