小琉球為全球少數的大型珊瑚礁島，潮間帶生物種類眾多且多樣。近年來小琉球每年均湧入大量的遊客，遊憩的衝擊使得潮間帶生物多樣性與生物族群產生急劇的變化。為瞭解遊憩衝擊對小琉球潮間帶物種的組成與族群分布的影響，本研究於2011年5-6月進行潮間帶遊客人數與遊憩密度調查，並於2-6月進行垂直海岸線50公尺的穿越線物種族群監測。在肚仔坪、杉福、蛤板灣、漁埕尾和龍蝦洞等5個主要潮間帶，以遊憩密度較高的漁埕尾和杉福潮間帶的物種豐富度、均勻度和生物多樣性指數最高，但族群密度卻較低。而以遊客數量較少的龍蝦洞和肚仔坪的族群密度較高，其中最優勢的物種為蜈蚣櫛蛇尾（Ophiocoma scolopendrina），其次為梅氏長海膽（Echinometra mathaei）。蜈蚣櫛蛇尾的族群優勢度對遊憩密度有明顯的反應，是小琉球潮間帶遊憩衝擊重要的生物指標。不同潮間帶的族群數量的空間分布型態均不相同，但在每月間之族群分布型態，沒有明顯的改變，其受到每月間時間變化的影響較少。在遊憩密度較大的潮間帶，個體明顯的集中於離岸25公尺的中潮帶以下區域。遊客數量較多的潮間帶的物種族群密度，已降為遊客較少地區的9.1%。為了潮間帶生物資源的保育，未來對小琉球地區潮間帶遊客的人數、遊憩活動與旅遊方式，均需謹慎明智的規劃與管理。

Liuchio Hsu is one of the few big coral islands in the world. Varied and abundant species inhabit its intertidal zones. Recently, numerous visitors have flocked to the island every year, and these recreational visitors have significantly changed the biodiversity and biological populations in the intertidal zones. To understand on and population distribution, this study was conducted from May to June to survey visitor numbers and recreation density. The population was monitored using a 50-meter transection line perpendicular to the seashore from February to June of 2011. Among Duzeiping, Sanfu, Gebanwan, Yuchengwei and Lonshadong, the five main intertidal zones, in Yuchenwei and Sanfu, which have higher recreational densities, species richness, evenness and biodiversity index were higher than elsewhere, but the population densities were lower. There were fewer visitors at Lonshadong and Duzeiping than at the other three zones, and the population densities at these two zones were higher. The most dominant species was Brittle star (Ophiocoma scolopendrina) followed by Mathae's urchin (Echinometra mathaei). The dominant ratio of Brittle star to recreational density, a biological indicator of recreational impact on intertidal zones in Liuchio Hsu. The spatial distribution patterns of populations varied among intertidal zones, but did not obviously differ from month to month. The patterns were little affected by monthly temporal changes. In the higherrecreational- density intertidal zones the individuals were obviously concentrated in the mid-tidal area 25 meters offshore. The population density of the more-visited intertidal zones the less-visited areas. To conserve intertidal biological resources, visitor numbers, recreational activities and tourism patterns for the intertidal zones of this island should be carefully and wisely planned and managed in the future.