七股地區淺坪虱目魚塭及文蛤池底棲動物相之研究

A Study on the Benthic Fauna of Shallow-water Milkfish Ponds and Hard Clam Ponds in Qigu

本研究自 2012-2013 年於七股針對 9 個淺坪虱目魚塭及 10 個文蛤池進行調查，共採得底棲動物 3633 隻，分 19 科 23 種。各類群中以多毛類 12 種最多，螺貝類 7 種次之。其它生物包含水生昆蟲幼蟲（搖蚊及牙蟲）、端足類及海葵。兩種魚塭底棲動物的組成有顯著差異。虱目魚塭共紀錄 8 種，以小頭蟲（Capitella sp.）、栗螺（Stenothyra sp.）及搖蚊幼蟲為優勢。文蛤池共紀錄 21 種，以腺帶刺沙蠶（Neanthes glandicincta）及褐皮粗米螺（Didontoglossa koyasensis）為優勢。在群聚結構比較上，文蛤池採得底棲動物的種類數及多樣性較高。虱目魚塭則具較高的平均密度並以小頭蟲等投機物種為優勢。利用 AMBI（AZTI’s Marine Biotic Index）及 M-AMBI（Multivariate-AMBI）評估兩種魚塭底土的生態環境品質。兩指標評估的一致性程度屬好的等級。多數文蛤池被歸為好的生態環境狀態；虱目魚塭則為中等至差。由底棲動物群聚結構及兩指標評估結果暗示，淺坪虱目魚塭可能承受較高的有機質物，導致底質生態環境品質較差。 Nine shallow-water milkfish (chanos chanos) ponds and ten hard clam (Meretrix lusoria) ponds in Qigu were surveyed for benthic fauna from 2012 to 2013. A total of 3,633 individuals belonging to 19 families and 23 species were collected. Overall, 12 polychaete species and seven mollusc species were found. Others include aquatic insect larvae (chironomidae and hydrophilidae), amphipod, and sea anemone. Benthic fauna communities were significantly different between the two pond types. A total of eight species were found in milkfish ponds, in which Capitella sp., Stenothyra sp., and chironomid larvae were dominant. A total of 21 species were found in hard clam ponds, in which Neanthes glandicincta and Didontoglossa koyasensis were dominant. Benthic fauna species richness and diversity were higher in hard clam ponds, but the mean density was higher in milkfish ponds and the dominance of opportunistic species such as Capitella sp. AZTI's Marine Biotic Index (AMBI) and Multivariate-AMBI (M-AMBI) were applied to access the benthic ecological status of ponds. A “good” level of agreement was between AMBI and M-AMBI. Most hard calm ponds were classed at “good” ecological quality, but milkfish ponds ranged between “moderate” to “poor”. The results of benthic fauna community and the two indices suggest that shallow-water milkfish ponds might have higher organic matter loading, which led to poorer ecological quality status.

Nine shallow-water milkfish (chanos chanos) ponds and ten hard clam (Meretrix lusoria) ponds in Qigu were surveyed for benthic fauna from 2012 to 2013. A total of 3,633 individuals belonging to 19 families and 23 species were collected. Overall, 12 polychaete species and seven mollusc species were found. Others include aquatic insect larvae (chironomidae and hydrophilidae), amphipod, and sea anemone. Benthic fauna communities were significantly different between the two pond types. A total of eight species were found in milkfish ponds, in which Capitella sp., Stenothyra sp., and chironomid larvae were dominant. A total of 21 species were found in hard clam ponds, in which Neanthes glandicincta and Didontoglossa koyasensis were dominant. Benthic fauna species richness and diversity were higher in hard clam ponds, but the mean density was higher in milkfish ponds and the dominance of opportunistic species such as Capitella sp. AZTI's Marine Biotic Index (AMBI) and Multivariate-AMBI (M-AMBI) were applied to access the benthic ecological status of ponds. A “good” level of agreement was between AMBI and M-AMBI. Most hard calm ponds were classed at “good” ecological quality, but milkfish ponds ranged between “moderate” to “poor”. The results of benthic fauna community and the two indices suggest that shallow-water milkfish ponds might have higher organic matter loading, which led to poorer ecological quality status.