頁籤選單縮合
題 名 | 綠島珊瑚及星野黑皮海綿覆蓋率之空間分布及年間變動調查=Spatial Distribution and Temporal Variation of the Cyanobacteriosponge, Terpios Hoshinota, and Benthos Composition on the Coral Reefs of Green Island |
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作 者 | 陳淑麗; 郭兆揚; 陳昭倫; | 書刊名 | 國家公園學報 |
卷 期 | 19:4 2009.12[民98.12] |
頁 次 | 頁32-45 |
分類號 | 361.526 |
關鍵詞 | 底棲群聚; 星野黑皮海綿; 石珊瑚生長形; 珊瑚群聚功能群; Benthos community; Terpios hoshinota; Hard coral morphology; r-K-S; |
語 文 | 中文(Chinese) |
中文摘要 | 綠島周圍海域珊瑚礁生態系受到星野黑皮海綿大量出現的威脅,所以星野黑皮海綿在綠島的空間分布與年間的變化須進一步的調查。本研究分別於2007和2008 年在綠島,包括北岸的柴口、公館、龍門岩;東岸的柚子湖、睡美人、朝日溫泉、西岸的大白沙與石朗等8 個樣點,使用隨機穿越線攝影調查法,針對珊瑚礁底棲群聚、星野黑皮海綿覆蓋率、活珊瑚受星野黑皮海綿覆蓋率及星野黑皮海綿覆蓋珊瑚生長形專一性進行隨機穿越線攝影普查,此外也進行不同深度(1-3 m、5-6m、8-10m)的調查。其中公館在2008 年進行重複調查,以了解各指數在地點間、深度間與時間尺度上是否具有顯著性差異。底棲群聚調查結果顯示,各樣點皆是以珊瑚為主,其中在大白沙、龍門岩、公館、石朗和柚子湖的珊瑚覆蓋率超過50%,此外軟珊瑚在石朗為28.63%,顯著高於其他海域。星野黑皮海綿分布在8 個地點間的覆蓋率亦有顯著的差別。整體而言在北岸與東岸較西岸高,其中柚子湖(東)12.09%最高、其次為公館(北) 10.92%、睡美人(東) 9.78% 與柴口(北) 6.95%。星野黑皮海綿的分布會隨著深度遞減,顯示其好發在非常淺(1-3 m)的海域。而星野星野黑皮海綿對覆蓋不同生長形的珊瑚並無專一性,但多覆蓋在表覆形軸孔和表覆形珊瑚上,推測由於這兩種珊瑚在淺水域為優勢,因此此現象可能為海綿與優勢珊瑚在空間上的競爭結果。在公館進行不同年度重複調查結果顯示,底棲群聚及星野黑皮海綿覆蓋率在不同年間皆無顯著差異(F = 2.46, p = 0.08, F =3.04, p = 0.09)。整體而言,星野黑皮海綿好發的地區,可能和當地的底棲群聚組成、珊瑚生長形及深度有很大的關係。珊瑚群聚功能群分析(r-K-S analysis)顯示綠島海域中,珊瑚生長形多樣性較高的地點為龍門岩、柚子湖和睡美人,並非是珊瑚覆蓋率高的大白沙與石朗。生長形多樣性高不僅表示當地海域的珊瑚功能群種類較多,受到環境影響時的耐受力(resistance)較佳,也會增加棲地複雜度,提供生物生存、發育的空間,因此應將龍門岩、柚子湖和睡美人列為重點保育標的。此外,r-K-S 分析也顯示綠島底棲群聚受到環境的影響而面臨緊迫,包括颱風、季風、環境變遷與人為活動影響等。 |
英文摘要 | Coral reefs around Green Island have been threatened by a massive outbreak of Terpios hoshinota, a cyanobacteriosponge, but there is little baseline information on this outbreak. The spatial distribution of benthos around Green Island was was initiated in 2007. The distribution of horizontal coverage and depths of T. hoshinota, T. hoshinota that had invaded coral and other benthos community were studied using random video transect method at eight sampling sites at various depths (1-3m, 5-6m and 8-10m). The investigation also included scleractinia morphology and specific invasion behavior in relation to coral morphologies. The eight sites were distributed in three regions, i.e. north coasts of Gongguan (GN), Chaiko (CK), and Longmenyan (LY); east coasts of Youzhu (YH), Shuimeiren (SR) and Wenquan (WQ); and west coasts of Daibaisha (DS) and Shilang (SL). The same investigation was repeated in Gongguan (GN) in 2008 to examine yearly variation. Results showed that benthos community, regardless of sites, were dominated by corals, with over 50% at 4 sites (i.e. DS, LY, GN, and YH) and 35.53% at SL. As for soft coral coverage, SL showed largest coverage with 28.63 %. Area covered with T. hoshinota varied significantly with sites. The coverage of T. hoshinota was found larger at northern and eastern coastal sites than at the western coastal site of the Island. The highest coverages were 12.09%, 10.92%, 9.78% and 6.95% at YH, GN, SR and CK, respectively. All these sites were found in northern and eastern coasts of the Island. The coverage of T. hoshinota, more abundant at 1- to 3-m depths, decreased with depth. T. hoshinota was a non-specific species to the morphology of coral, but invaded massively on encrusting form of corals. This was perhaps due to the competition of T. hoshinota with dominant. growth form of encrusting corals. The coverage of benthos communities including T. hosinota at GN was not significantly different between the two-year investigation. It was concluded that the distribution of T. hoshinota was controlled by the type of benthos, composition of coral morphology and depth. The r-K-S analyses indicated that biodiversity varied with sites with higher at LY, YZ, and SR, and lower at DS and SL sites that were higher in coral coverage. The r-K-S analyses also indicated benthos community of Green Island has been subjected to natural disturbances (such as typhoon, monsoon) and anthropogenic disturbances at various intensities. |
本系統中英文摘要資訊取自各篇刊載內容。