博士 / 國立臺灣大學 / 海洋研究所 / 101 / Striped marlin, Kajikia audax, is a highly migratory species distributed throughout tropical and temperate waters in the western and central North Pacific Ocean (WCNPO). In this study, the habitat preferences of striped marlin in the WCNPO were examined using generalized additive models (GAM). Fishery catch rates were modeled as a function of remotely-sensed environmental covariates, including sea surface temperature (SST), chlorophyll-a concentration (CHL), mixed layer depth (MLD) and sea-surface height anomalies (SHA). SST explained the largest proportion of the deviance, and was therefore considered the best predictor for the habitat of striped marlin. Spatial distributions of the relative density of striped marlin indicated that there is a seasonal north–south migration, and that the highest densities occur in the central North Pacific Ocean. The preferred habitat characteristics of striped marlin in high density areas were identified as SST between 23-26°C, MLD within 30 m depth, and CHL around 0.08 mg m-3. There was no evident preferred range for SHA.
Catch per unit effort (CPUE) data for striped marlin from the Taiwanese longline fleet in the WCNPO were standardized using GAM, with SST, year, month, fishing area, and the interactions used as the explanatory variables. The standardized CPUE series for this fleet, as well as those from the Japanese distant-water, Japanese coastal, and Hawaiian longline fleets were used in a non-equilibrium surplus production model (ASPIC) to assess the stock status of striped marlin in the WCNPO. Results showed that the maximum sustainable yield (MSY) estimated for this stock was 4,812 tons, and that the stock was both overfished and subject to overfishing. The values of B2010/BMSY and F2009/FMSY were estimated at 0.20 and 2.53, respectively. The projection analysis suggested that the total allowable catch (TAC) should be reduced to 1,700 tons per year for sustainable use of this resource.
| Identifer | oai:union.ndltd.org:TW/101NTU05279029 |
| Date | January 2013 |
| Creators | Yung-Hsiang Lien, 連永祥 |
| Contributors | 孫志陸 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 87 |
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