| Autor: |
Ming-An Lee, C.-C. Lai, Long-Jing Wu, Kwang-Ming Liu, J.-S. Weng, M.-K. Hung |
| Rok vydání: |
2013 |
| Předmět: |
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| Zdroj: |
Journal of Applied Ichthyology. 29:990-1000 |
| ISSN: |
0175-8659 |
| Popis: |
Summary An increase in yellowfin tuna (Thunnus albacares) catch by danish seine fisheries around the subsurface fish aggregating devices (FADs) in southern Taiwan waters has been a concern of local government and environmental groups. However, the attraction mechanism of aggregating tunas at the subsurface FADs is still poorly understood. The objective of this study is to examine the fine-scale vertical and horizontal movements of juvenile yellowfin tunas around a subsurface FAD. In total, 53 tunas (35–81 cm fork length) were tagged with ultrasonic telemetry tags and released at a subsurface FAD in the waters off Shiao-Liu-Chiu Island, southwestern Taiwan from October 2008 to December 2009. These tunas stayed at the subsurface FAD for up to 31 days, with daytime vertical movement depths averaging 60–80 m at a maximum depth of 250 m. At night, the tuna gathered at a shallow depth of 40 m. The mean depth of vertical movement in the daytime is significantly different from that of the nighttime (P |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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