Fouling characteristics of cnidarians (Hydrozoa and Anthozoa) along the coast of China

Hydrozoans and anthozoans are an important component of a great variety of marine communities, particularly abundant and ubiquitous as part of the fouling assemblages around the globe. Several negative impacts have been associated to their occurrence on artificial substrata. In the coastal waters of China, a total of 76 species of fouling cnidarians were observed and classified. According to the occurrence frequency or biomass, the major species in the Bohai and Yellow Seas were Ectopleura marina, Bougainvillia sp., and Eudendrium capillare ; in the East China Sea Anthopleura nigrescens, Diadumene lineata , and Ectopleura crocea ; and in the South China Sea Clytia sp., Obelia sp., and Actiniaria spp. The peak period of settlement of most species was mainly in summer and autumn. With the decrease of latitude, species number increased greatly and even cnidarian fouling was observed all year round in the East and South China Seas. Salinity was another factor affecting species distribution. Naturally, immersion time of substrata also directly affects the characteristics of cnidarians in fouling communities.