Alternative Assessment Methods Applied to the Hairtail (Trichiurus lepturus) Stock in the Aru Sea as an Example

Chao-Hsiung Cheng ； Tsuyoshi Kawasaki ； Kuo-Ping Chiang ； Chuan-Hung Ho

《Journal of Marine Science and Technology》 21卷特刊 (2013/12) Pp. 223-229

https://doi.org/10.6119/JMST-013-1220-12

並列摘要

The Aru Sea off Indonesia is a major fishing ground for Taiwanese distant-water otter trawlers. The hairtail, an economically important demersal fish, is abundant in that area. The assessment methodology in this paper extends previous studies on hairtail fisheries by considering migration within the fishing grounds. This model is based on conventional Leslie-Delury method but makes different assumptions on stock movement and the relationship between stock abundance and catch per unit effort. It was applied to retrospective data from the hairtail fisheries in the Aru Sea. In addition, the depletion method was used to estimate the abundance of hairtail and to assess the status of the hairtail stock. The hairtail stock was estimated at three periods of a year: aggregation in March, dispersion between April and September, and aggregation again between October and December. Fishing mortality coefficients for the three periods were estimated to be 0.728, 0.232 and 0.395 month^(-1), respectively. Clearly, the hairtail population was under high fishing pressure. This study revealed that the hairtail population was overexploited. The stock status and the high fishing mortality indicated that appropriate management measure is required.

並列關鍵字

Trichiurus lepturus ； stock assessment ； depletion method

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