AbstractAbout 30 species of exotic marine organism have been int roduced to China for mariculture and planting at present , including ten species of fish , two species of shrimp , nine species of mollusks , one species of echinnoderm , four species of alga and two species of halophytic weeds. Among the alien mariculture species , only a few of them such as kelps , L aminaria japonica and Undaria pinnatifidab , and scallops , Argopecten irradians and Patinopecten yessoensis , have been developed into industries and brought big economic value. Most of them have failed to succeed in culture and perhaps produced potentially adverse impacts on native marine ecosystems. Over 27 aquaria have been built in the coastal cities in China in the last decades , and hundreds of marine ornamental plant s and animals were imported and exhibited in these aquaria. Hundreds of exotic species were t ransported to the harbors by ship hull fouling , boring , dry and semi-dry ballast , and water ballast in China.

The alien marine species have produced a great deal of dest ructive impact on the native marine eco - environment . First , the exotic marine species compete with natives. For example , Spartina anglica was introduced to Fujian Province coast from Britain and cultured on the beach , but the weed has exiled native fish , shrimp and mollusks and killed the mangrove on the beach in the past years. The decline of the native echinoderm , Strongylocentrotus nudus ,on the coast in Dalian corresponds closely with the arrival of another echinoderm , Strongylocentrotus intermedius , from Japan , which was introduced in 1989 for mariculture and can compete for food with the native urchin. Second , mating between some alien and native species can lead to an extinction of the native marine species by replacement of its genes. Forexample , the Japanese scallop , Patinopecten yessoensis , can hybridize with thenative species , Chlamys farreri , because they have a similar propagation period and have completed hybridization in the laboratory. Thirdly , pathogens can be int roduced by alien species. Forexample ,large scale mortality broke out in the northern coast in China among maricultured Chinese shrimp , Penaeus chinensis , in 1993 and has continued to date. One of main reasons was that propagules of Japanese shrimp , Penaeus japonicus , with virus pathogen was int roduced. Fourthly , brown tide harms more and more of the coast in China. Many species of red tide alga are believed to have been introduced in ship water ballast and are considered to be responsible for the ecological disaster. We proposes the following strategic recommendations on invasive alien marine species management in China : (1) limit the int roduction of alien marine species for mariculture or planting ; (2) st rengthen quarantine of imported alien marine organisms and their products ; (3) take integrated measures and policies to prevent and eradicate harmful alien marine species ; (4) establish an effective and harmonious management system for alien marine species.