2010－2017後壁湖海洋資源保護示範區白棘三列海膽與喇叭毒棘海膽調查報告

Survey of Sea Urchin, Tripneustes gratilla and Toxopneustes pileolus, in Houbi Lake Marine Resource Reserve Exhibition Center, 2010-2017

墾丁國家公園管理處自 2010 年開始在後壁湖海洋資源保護示範區進行海膽數量調查，分析發現海膽族群變動很大。白棘三列海膽（Tripneustes gratilla）月密度介於 0.1-7 顆/10 m2 之間，總平均密度是 1.4 顆/10 m2，月別樣區出現率則在 8%-73%之間。喇叭毒棘海膽（Toxopneustes pileolus）波動較輕微月密度介在 0.3-2.6 顆/10 m2 之間，平均密度為 1.1 顆/10 m2，月別樣區出現率在 22%-85%之間。我們發現兩種海膽族群都是密集結群且不均勻地散佈在監測區中，海膽族群呈現明顯的塊狀分布現象，且有族群常見出沒海域，但在 2013 年 8 月後出現族群量驟減與熱點偏移情形，這可能是颱風造成的影響。唯有連續不中斷的長期調查才能夠作為資源變動的參考基準，因此發展可行的長期監測策略是必要的。本文顯示由國家公園管理處人員加上志工的參與，是未來達成長期監測當地環境的可行策略。 Kenting National Park Headquarters have been conducting a monthly sea urchin monitoring survey in Houbi Lake Marine Resource Reserve Exhibition Center since 2010. As of 2017, the results show that sea urchin populations fluctuate widely from month to month. The average density of Tripneustes gratilla is 1.4 individuals/10 m2 , ranging between 0.1 and 7 individuals/10 m2 , and the monthly distribution occurrence ranges between 8% and 73% of the survey area. The monthly population fluctuation of Toxopneustes pileolus is less than that of T. gratilla, which ranges between 0.3 and 2.6 individuals/10 m2 , with an average density of 1.1 individuals/10 m2 . Distribution occurrence ranged between 22% and 85% of the survey area. We found that the two sea urchin species populations are highly aggregated and unevenly distributed in the surveyed area. Both sea urchin populations show a greatly patched distribution and commonly occurred in certain habitats. There was an abrupt population decline and a shift in distribution hotspot after August 2013, which may be due to typhoon. As a reference for resource fluctuation of sea urchins, continuous and long-term observation are required. It is necessary to develop sustainable strategies to maintain a long-term survey, and this report shows that the involvement of National Park staff and volunteers is a suitable strategy to carry on a long-term environment monitoring project in the future.

Kenting National Park Headquarters have been conducting a monthly sea urchin monitoring survey in Houbi Lake Marine Resource Reserve Exhibition Center since 2010. As of 2017, the results show that sea urchin populations fluctuate widely from month to month. The average density of Tripneustes gratilla is 1.4 individuals/10 m2 , ranging between 0.1 and 7 individuals/10 m2 , and the monthly distribution occurrence ranges between 8% and 73% of the survey area. The monthly population fluctuation of Toxopneustes pileolus is less than that of T. gratilla, which ranges between 0.3 and 2.6 individuals/10 m2 , with an average density of 1.1 individuals/10 m2 . Distribution occurrence ranged between 22% and 85% of the survey area. We found that the two sea urchin species populations are highly aggregated and unevenly distributed in the surveyed area. Both sea urchin populations show a greatly patched distribution and commonly occurred in certain habitats. There was an abrupt population decline and a shift in distribution hotspot after August 2013, which may be due to typhoon. As a reference for resource fluctuation of sea urchins, continuous and long-term observation are required. It is necessary to develop sustainable strategies to maintain a long-term survey, and this report shows that the involvement of National Park staff and volunteers is a suitable strategy to carry on a long-term environment monitoring project in the future.