英文摘要 |
The production of the Pacific saury fishery from Taiwan fleets in 2005 was 111,500mt, which is the highest record in Taiwan and larger than that in the last year (2004) with the amount of 50,000mt. As to the fish stock, the CPUE in 2005 was at the high point in the range of normal fluctuation. The distribution of the fishing area in 2005 was similar to that in 2004, but the west side of the former was close to the Hokkaido and the south extended to 36oN. In addition, the CPUE and catch were large in the Hokkaido fishing area. In general, the saury fishing area moved northeasterly and concentrated solidly in the stage after the EEZ implement in Japan (2000~2004), comparing to the stage before the EEZ implement (1994~1999). Meanwhile, the SST in 2000~2004 (11~19 oC) was lower than that in 1994~1999 (13~22 oC). The results of the analysis on the saury catch and its size composition in 1994~2004 showed that there were obvious fluctuations among the fishing months and years. The proportion of the large size in the catch in 2005 was 83.3 %, which was larger than that in 1994~1999 (70.5% of average) and 2000~2004 years (60.8%). This indicated that the high catch in 2005 may relate to the increase of the large-size fish in the catch. As to the spatial autocorrelation analysis, maximums of the Moran's I mostly appeared at K=3 in 1994~2005 and Moran's I dropped progressively with the increase of the K value. The analysis of the Spearman’s correlation showed that there was a significantly negative correlation between the Moran's I and the sea water temperature (r=-0.615, P =0.033), and the Moran's I showed a significantly negative correlation with the CPUE if it was lagged by one year (r =-0.587, P =0.045). |