澎湖鎮海海草床大型無脊椎動物之組成分析

Composition analysis of macroinvertebrates in the seagrass beds of Chenhai, Penghu County, Taiwan

澎湖縣白沙鄉鎮海灣海草床係澎湖縣內面積最大的海草床，擁有豐富的生態資源。近年來，由於航道開發的影響，海草床面積有所減少。因此，各單位近年亦執行多項海草床評估計畫，以瞭解海草床現況並制定相應的保育措施。過去澎湖縣內的海草床調查研究多集中在魚類方面，而對無脊椎動物的調查資料則相對較少，因此，本研究於2022年3月至2023年4月，每月至鎮海海草床進行無脊椎動物之生物相調查，旨在瞭解海草床中無脊椎動物的組成，以提供後續保育工作之參考依據。調查期間，共發現107種無脊椎動物，其中以軟體動物門53種最多，其次為節肢動物門41種。在鎮海海草床的螺貝類物種中，海蜷科物種為第一優勢種。螺貝類物種之多樣性指數顯示，種類豐度介於0.29-1.31；優勢度介於0.94-1.00；歧異度介於0.10-0.65；均勻度介於0.07-0.41，根據ANOVA分析，種類豐度無明顯季節變化；優勢度、歧異度及均勻度等3項指數則呈現季節變化。未來須透過持續的基礎生態調查，以更全面評估保護區的可行性。

The seagrass bed in Chenhai Bay, Baisha Township, Penghu County, is the largest within Penghu County and possesses abundant ecological resources. In recent years, the area of the seagrass bed has decreased due to the impact of channel development. Consequently, various organizations have implemented several seagrass bed assessment projects to understand the current status and formulate corresponding conservation measures. Previous research on seagrass beds in Penghu County has mainly focused on fish, with relatively limited data on invertebrates. Therefore, in this study monthly surveys of invertebrate biodiversity in the Chenhai seagrass bed were conducted from March 2022 to April 2023, aiming to comprehend the composition of invertebrates in the seagrass bed and provide a reference basis for subsequent conservation efforts. During the survey period, a total of 107 species of invertebrates were identified, with the phylum Mollusca being the most abundant with 53 species, followed by the phylum Arthropoda with 41 species. Among the gastropod species in the Chenhai seagrass bed, species of the family Batillariidae emerged as the most dominant. Diversity indices for gastropod species indicated a range of species richness from 0.29 to 1.31, dominance from 0.94 to 1.00, diversity from 0.10 to 0.65, and evenness from 0.07 to 0.41. According to ANOVA analysis, species richness showed no significant seasonal variation, while dominance, diversity, and evenness indices exhibited seasonal changes. In the future, continuous foundational ecological surveys are necessary for a more comprehensive assessment of the feasibility of the conservation area.