The Development of Subtidal Fouling Assemblages on Artificial Structures in Keelung Harbor, Northern Taiwan

基隆港水下設施表面附著生物的群聚發展

林幸助(Hsing-Juh Lin) ； 邵廣昭(Kwang-Tsao Shao)

《Zoological Studies》 41卷2期 (2002/04) Pp. 170-182

摘要

我們在基隆港內持續進行了18個月的試版掛放實驗，以了解不同基質、不同掛放季節與時間長短對亞熱帶海域水下附著生物群聚發展的相對重要性。四種基質包括裸鋼、不銹鋼、陰極保護鋼及混凝土，分別於秋季及春季時掛放於水下，每隔3-6個月回收部分試版進行採樣。結果顯示基質並不會影響其附著生物的群聚發展，但是春季掛放試版較秋季掛放試版有較高生物量與較多的附著生物種類生長。春季及秋季試版之生物量在掛放時間18個月時皆達到最高，但是生物種類在12個月時卻是最多。聚類與空間排序分析結果亦顯示附著生物群聚結構會受到掛放季節與掛放時間的影響，但不會因基質而有所不同。在18個月的掛放期間內，巨牡蠣（Crassostrea gigas）為春季試版的主要優勢種類，但秋季試版的優勢種類則隨掛放時間的長短而改變，因此掛放季節與時間對水下附著生物群聚發展的影響較大。然而春季試版與秋季試版在附著生物量與群聚結構間的差距會在掛放12個月後縮小，顯示即使試版於不同季節時掛放，其附著生物群聚的發展仍會依循類似的途徑，這可能是由於這些群聚的發展是取決當時水中附著生物幼生的量與種類。因此亞熱帶海域水下附著生物群聚的發展過程會同時受到當時水中幼生的種類與數量，以及該基質先前已著生的生物種類的影響。

關鍵字

基質 ； 掛放季節 ； 掛放時間 ； 巨牡蠣

並列摘要

Effects of substratum, its submersion season, and submersion period on the development of subtidal fouling assemblages were examined for a period of 18 mo in a subtropical harbor. Four types of artificial surfaces, including steel, stainless steel, cathodically protected steel, and concrete, were initially submersed in fall and spring, respectively, and sampled every 3-6 mo. There is little evidence that type of substratum influenced the development of fouling assemblages. However, richer taxa and greater biomass of fouling assemblages occurred on spring-than on fall-submersed plates. Fouling biomass reached a maximum at the end of the study period, but the taxa were richest at the end of 12 months. Classification and ordination analyses show that the species compositions of fouling assemblages were structured by submersion season and submersion period of the substratum, but not by the nature of the substratum itself. The oyster, Crassostrea gigas, dominated spring plates throughout the study period, but the assemblages on fall plates were highly variable. This indicates that submersion season and submersion period of the substratum are more important than type of substratum in the development of subtidal fouling assemblages. However, the abundance and species composition on spring and fall plates became less dissimilar by the end of 12 mo. This suggests that development takes the same course even with different seasons of submersion. It is likely that the fouling species acted in individualistic manners, and the assemblages were composed simply of fouling species which arrived at that time. Our results demonstrate that the developmental process is greatly affected by seasonal fluctuations in larval abundance and historical components on a substratum.

並列關鍵字

Substratum ； Submersion season ； Submersion period ； Crassostrea gigas