碩士 / 臺灣大學 / 海洋研究所 / 98 / The Japanese anchovy (Engraulis japonicus) larval fishery is one of the important fisheries in Taiwan, and the fishery catch has significantly decreased since the 1990s. The abundance of spawning adults likely influences the recruitment process and thus the fishery catches. However, Japanese anchovy is known as a multi-batch species with many different spawning grounds, which makes the field study of the onset of spawning migration and its possible migration routes difficult.
Here, an approach based on a coupled fish behavior-hydrodynamic model is used to simulate spawning migration of Japanese anchovy. The physical part consists of an ocean circulation model - Dual-grid Pacific Ocean Model (DUPOM), which is based on the fourth-order accurate, collocated Arakawa-A grid DieCAST (Dietrich/Center for Air Sea Technology) model. The change of Changjiang discharge is also included for investigating the potential influence of reduction in discharge causing by Three Gorge Dam. The biological part uses the Lagrangian particle tracking program to simulating fish migration with a primarily approximation of fish swimming behavior.
The simulation results suggest that the spawning migration of Japanese anchovy may be aided by the China Coastal Current (CCC). In addition, the Changjiang discharge has significant influence on the migration of Japanese anchovy. The swimming behavior of anchovies is crucial during spawning migration, as it provides extra velocity for fish moving farther and closer to the coastal area. Results in this research demonstrate that a physical model coupled with a simplified biological model can help us better understand how the biological processes and marine environment affecting the fish population.
| Identifer | oai:union.ndltd.org:TW/098NTU05279004 |
| Date | January 2010 |
| Creators | Chen-Yi Tu, 杜貞儀 |
| Contributors | Chih-hao Hsieh, 謝志豪 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | en_US |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 43 |
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