Antifouling potential of marine sessile organisms from the southeast coast of china against the barnacle Balanus albicostatus
【英文摘要】Marine fouling organisms constitute a worldwide technical and economical problem. Environmental and human health problems associated with the use of toxic antifoulants makes it a necessity to develop environmentally friendly alternatives (Yebra et al., 2004). The present study investigated the antifouling activity of a series of hexane, ethyl acetate, ethanol and aqueous extracts from Ulva pertusa, Thalassia hemprichii, Enhalus acoroides, Tedania anhelans, Halichondria sp., Bugula neritina, Tubularia mesembryanthemum, Anthopleura sp., Notarcus leachii cirrosus, Styela plicata and Styela canopus from the southeast coast of China. Settlement inhibition of cyprid larvae of the barnacle Balanus albicostatus was used to evaluate antifouling efficacy. The EC50 value (the concentration of extract that reduced the settlement rate by 50% relative to the control) was estimated using the Spearman–Karber method. Screening of the 44 extracts showed antifouling activity in 90.9% of the hexane extracts followed by 90.9% of ethyl acetate, 72.7% of ethanol, and 36.4% of aqueous extracts. The hexane extracts of T. mesembryanthemum, N. leachii cirrosus and S. canopus, the ethyl acetate extracts of B. neritina and N. leachii cirrosus, and the ethanol extracts of B. neritina and Anthopleura sp. were the most active in inhibiting B. albicostatus settlement, with EC50 all below 50 μg/mL. At least 1 of the 4 extracts of each tested species exhibited antifouling activity, suggesting that all 11 marine sessile organisms harbored antifouling substances and they may have evolved chemical defenses against biofouling on their surfaces. The present findings could form the basis for exploring the compounds responsible for antifouling activity in these marine sessile organisms, which could be exploited not only for elucidating their potential chemical antifouling mechanisms but also for developing novel antifouling technology.