On the relationship between El Nino/Southern oscillation and South Pacific albacore
Lu, H.J.; Lee, K.T.; Liao, C.H.
Fisheries Research 39(1): 1-7
1998
ISSN/ISBN: 0165-7836
Accession: 011088332
The influence of El Nino/Southern oscillation (ENSO) episodes on South Pacific albacore (Thunnus alalunga) is analyzed using historical catch per unit effort (CPUE) data collected from the Taiwanese distant-water longline fishing fleet, Southern oscillation indices and large scale measurements of seawater temperature. Two effects were identified from a time series analysis: (1) relatively low CPUE followed the onset of ENSO episodes with 8 and 4 yr time lag in fishing grounds between 10degreeS and 30degreeS and south of 30degreeS, respectively; and (2) towards the beginning of ENSO episodes CPUE was slightly higher in fishing grounds between the equator and 10degreeS. The time lag of the first effect corresponds to the time intervals that would be expected before the recruitment for the fish spawned during ENSO episodes. The second effect is interpreted as a result of the anomalous temperature structure of the seawater. The rise of the mixed layer depth (MLD) in the equatorial region as well as the narrowing volume of water comprising the albacore's temperature preference in the subtropical region would both be expected to lead to a (slight) increase in the hook rate of albacore in the two regions.