The possible impacts of climatic factors on the fish landing fluctuations in the waters of east Taiwan

Autor: kuo, kun-fang, 郭坤芳
Rok vydání: 2015
Druh dokumentu: 學位論文 ; thesis
Popis: 103
The study was tried to investigate the relationship between the climate variability factors and the annual fish landing during the period of 1983 to 2011 in the waters of eastern Taiwan using the Pearson correlation analysis and wavelet analysis. These and environmental factors including climate variability index have the north pacific gyre oscillation (NPGO), Pacific decadal oscillation(PDO), western Pacifci oscillation (WPO), Arctic oscillation (AO), Philippines–Taiwan oscillation (PTO), El Niño–Southern Oscillation (ENSO) and sea surface temperature. The results are as following: 1. The first eleven dominant species larger than 1% of total fishing landing in the east waters of Taiwan were including mackerel(53.96%), Coryphaena hippurus (8.79%), Decapterus maruadsi (6.04%), Trachurus japonicas (4.21%), shark (4.18%), Decapterus kurroide (3.17%), Auxis rochei (2.67%), Trichiurus lepturus (1.99%), Auix thazard (1.68%), Thunnus albacares (1.46%) and Katsuwonus pelamis (1.25%). All above are occupied 89.41% of total fishing landing in this water. Among them, it showed an increase trend for these species of Decapterus maruadsi, Trachurus japonicus, mackerel, Auxis rochei, shark, Thunnus albacares, Trichiurus lepturus, and Coryphaena hippurus, while a decrease trend was identified to these species of Decapterus kurroides, Katsuwonus pelamis and Auix thazard. 2. The relationship of fishing landing and climate variability index was varied by species. The landing of Trachurus japonicus and Auxis thazard are related to the PDO index, while Decapterus maruadsi, Trachurus japonicas and Thunnus albacares are related significantly in NPGO. In addition, AO and Niño3.4 index may affect the variation of Decanters kurroides and Shark, while SOI and WPO may significantly affect the landing of Thunnus albacores and Decapterus kurroides, respectively. Otherwise, the local sea surface temperature was suggested as a good indicator for evaluating the long-term trend for species of Decapterus maruadsi, Trachurus japonicas, mackerel, Auxis rochei, Thunnus albacares and Shark. 3. The Wavelet analysis shows the periodicity of multiple time scales was different by climatic indices. For PDO index, the periodicity is including the cycle of 9.2 and 5.1 year. For both of WPO and Niño 3.4, they have similar cycles of 5.7 year and 3.5~3.8 year. There are more complicated periodicity more than 3 cycles for SOI, PTO and AO indices, while there is simplify of one periodicity 10.6 year for NPGO, the longest. These periodicity characteristics of climate variability indices to fish landing was varied by species and discussed in this study. Key words：East waters of Taiwan, Climate variability, fish landing, mackerel
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