Algae versus animals in early fouling communities of the White Sea

Marine Ecology Progress Series

Sergey S. Malavenda¹  Vyacheslav V. Khalaman¹  Tat’yana A. Mikhaylova¹  Alexander Yu. Komendantov¹ 

关键词: Alternative community states;    Algal-invertebrate interactions;    Substrate orientation;    Competition;    Biofouling;    Community structure;    Shading;   

DOI  :  10.3354/meps11767

学科分类：海洋学与技术

来源: Inter-Research

【 摘 要 】

ABSTRACT: In epibenthic communities algae are usually predominant on sunlit substrates, while animals dominate shaded surfaces. Two possible factors that cause this are a higher competitive ability of algae and the evolutionarily defined differentiation of niches that results in animals avoiding competition with algae. We attempted to shed light on this duality by initally making the following assumption: if the key determinant for algal dominance on sunlit surfaces is niche differentiation rather than competitive exclusion, then a community already formed by animals must be impervious to algal expansion under any light conditions. This hypothesis was tested in a field experiment that used the early fouling communities developing in the upper water layer in the White Sea, Russia. Fouling communities were allowed to develop on the top sides and bottom sides of horizontal plates. After a period of exposure in water, the plates were inverted. It was shown that if the substrate orientation is reversed, the fouling community is transformed into the community that conforms to the new lighting conditions. An increased light intensity resulted in the degradation of the zoocenosis and changed its structure, whereas shading did not lead to degradation and change in the algocenosis, but caused stunting of algal growth. Our results indicate that algocenoses are more stable and have more competitive ability than zoocenoses in early fouling communities. The animal predominance on the shaded surfaces is likely to be a consequence of both competitive displacement of animals from the sunlit surfaces by algae and preferential colonization of the bottom surfaces by animals.

【 授权许可】

Unknown