TY - JOUR
T1 - Environmental effects on yellowfin tuna catch by the Taiwan longline fishery in the Arabian Sea
AU - Lan, Kuo Wei
AU - Lee, Ming An
AU - Nishida, Tom
AU - Lu, Hsueh Jung
AU - Weng, Jinn Shing
AU - Chang, Yi
PY - 2012/12
Y1 - 2012/12
N2 - In this study, we collected environmental variables to investigate their effects on the catch per unit effort (CPUE) of yellowfin tuna in the Arabian Sea during the period 1980-2005. We used an advanced time series analysis, including a state-space approach to remove seasonality, and wavelet analysis to investigate transient relationships. For large-scale environmental effects, we used the dipole mode index (DMI) to represent the Indian Ocean dipole; for local environmental factors, we investigated sea surface temperature (SST), thermocline depth and chlorophyll-a (chl-a) concentration. The main factors causing interannual variations in the CPUE might change with time. CPUE showed positive correlations with SST and DMI from the beginning of the 1980s to the middle of the 1990s. It also showed a significant coherence with chl-a, especially a long-term positive correlation for the regular longline fishery in 1998-2005 with a periodicity of 2 years. Both regular and deep longline CPUEs were found to have significant coherence with thermocline depth having a periodicity of 3 years. The relations were of opposite signs such that the shallow thermocline depth produced a high CPUE for the regular longline fishery and deep thermocline depth caused a high CPUE for the deep longline fishery.
AB - In this study, we collected environmental variables to investigate their effects on the catch per unit effort (CPUE) of yellowfin tuna in the Arabian Sea during the period 1980-2005. We used an advanced time series analysis, including a state-space approach to remove seasonality, and wavelet analysis to investigate transient relationships. For large-scale environmental effects, we used the dipole mode index (DMI) to represent the Indian Ocean dipole; for local environmental factors, we investigated sea surface temperature (SST), thermocline depth and chlorophyll-a (chl-a) concentration. The main factors causing interannual variations in the CPUE might change with time. CPUE showed positive correlations with SST and DMI from the beginning of the 1980s to the middle of the 1990s. It also showed a significant coherence with chl-a, especially a long-term positive correlation for the regular longline fishery in 1998-2005 with a periodicity of 2 years. Both regular and deep longline CPUEs were found to have significant coherence with thermocline depth having a periodicity of 3 years. The relations were of opposite signs such that the shallow thermocline depth produced a high CPUE for the regular longline fishery and deep thermocline depth caused a high CPUE for the deep longline fishery.
UR - http://www.scopus.com/inward/record.url?scp=84863822569&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84863822569&partnerID=8YFLogxK
U2 - 10.1080/01431161.2012.685971
DO - 10.1080/01431161.2012.685971
M3 - Article
AN - SCOPUS:84863822569
VL - 33
SP - 7491
EP - 7506
JO - International Joural of Remote Sensing
JF - International Joural of Remote Sensing
SN - 0143-1161
IS - 23
ER -