Influence of Whale-watching Boats on Behavior of Cetaceans at Haulien, Taiwan

• Main Authors: Wen-Jyh Yu, 游文志
• Other Authors: Bing-Ming Sung
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/38983317096745326920

碩士 === 國立東華大學 === 自然資源管理研究所 === 88 === The whale watching industry was initiated in 1997 in Taiwan. Up to the summer of 1999, there’re more than 12 whale watching boats, it will continue to grow in the nearly future. This study tried to evaluate the short-term impact on the cetaceans by whale watching activities. Nautical investigation was begun in Hualien during the summer time of 1998 and 1999. 241 groups of cetaceans belong to 11 species were recorded, Grampus griseus, Stenella attenuata, Stenella longirostris and Lagenodelphis hosei are the four common species. These four species are investigated the inter-relationship between whale-watching boats and the behavior of cetaceans. First, this study compared the behavior differences of dolphins displayed during “with-boat period” and “no-boat period”. Stenella attenuata, Stenella longirostris and Lagenodelphis hosei showed more frequently the negative responses when they confront the whale-watching boats, but not for the Grampus griseus. When the whale watching boats approach, diving was the most behavioral state for four kinds of dolphins. At the same time, Grampus griseus, Stenella attenuata and Lagenodelphis hosei will increase the frequency of changing directions. The herd of Stenella longirostris dispersed more frequently. In the patterns of surfacing and diving, the duration of surfacing sequence and the ratio of the Grampus griseus, Stenella attenuata and Lagenodelphis hosei and the diving frequency of the Stenella attenuata and Lagenodelphis hosei are significantly increased, but no significant differences for Stenella longirostris. Nevertheless, the swimming speed, number of aerial displays and diving durations in four kinds of whale don’t have significant responses. As a whole, behavioral state, changing direction, and the duration of surfacing sequence of the cetaceans were the most important factors for evaluating the disturbance to the whale watching boats. Secondly, this study analyzed the effects of whale-watching boats to the dolphins. In terms of the position between dolphins and boats, most whale-watching boats choose to get close to dolphins from the back with slow speed. When dolphins are surfed again, they choose more often far from the boats, not in front of them. When the number of boats increases, dolphins became more difficult to approach and the distances between dolphin diving and boats significantly increased. In order to sustain the ecological environment and economical benefit, this study provided three suggestions: (1)limiting the capacity of boats,(2)controlling the driving behavior of whale-watching boats, and (3) monitoring the cetacean ecology.