An abundance of studies have been done on the shift of fishing grounds and resources of migratory fishes of the ocean surface and middle layer near Taiwan in the past, but only few were done on the bottom dwelling fish species. In this research, the bottom dwelling lizardfishes, which are commonly used for processed sea food products were studied, to understand the shift of its resources during the 15 year period between 1997 and 2011, factoring the climate change index and environment factors of its habitat.
Results show Saurida undosquamis is the main species of the lizardfish caught in the south-western waters of Taiwan. Compare with water temperature, fishing season, spawning peak, landing, CPUE, feeding habits and geographic information, we can find which move to the shallow-warm waters after spawning peak in Jan.- Mar., and move back after September.Climate change index, SOI, PDO, MEI, Temperature and salinity factor at the depth of habitat are relevant to the shift in resources, whereas temperature and salinity of the water surface and river drainage are not. Judging from the variation of each climate change factor, the occurrence of La Niña raises the CPUE of lizardfishes, with a positive correlation with the temperature change, and a negative correlation with salinity at the depth of 100m under sea level.We assume that La Niña will bring strong northeast monsoon, conducive to the vertical mixing of different water layer. And nutrients through the Penghu Channel influx of promote, will increased lizardfishes resources. The sudden changes in the hydrological environment - typhoon will result in the increase in the of lizardfishes resources.
This research will help predict the change of lizardfish resources under the influence of hydrological environment changes in the future and will be critical information for making coping strategies.