Non-indigenous ascidians in southern California harbors and marinas
Non-indigenous ascidians in southern California harbors and marinas
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DOI：
10.1007/s002270050289
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发表时间：
1998-03-01
期刊：
影响因子：
2.4
通讯作者：
Lambert, G
中科院分区：
文献类型：
--
作者：
Lambert, CC;Lambert, G
南加州的许多大型港口形成了一个重要的沿海生态系统，但它们也是数千艘游艇和货船的主要目的地，这些游艇和货船经常长途跋涉。许多海洋生物群体，包括海鞘生物，现在已经被记录为由于远距离港口之间的快速船舶运输现象而经历了范围扩大。这导致了世界范围内非本土物种引入的速度迅速增加，但在南加州，船只交通的这些影响在很大程度上仍未得到研究。海鞘是固着的海洋滤食性动物，雌雄同体，经常自交；许多物种对各种环境条件都有耐受性，只需几周就能达到性成熟，繁殖期很长。本文记录了本世纪14种非本土物种抵达南加州港口的情况，其中13种持续存在：20世纪60年代以前有4种(海鞘、棍棒海鞘、褶皱海鞘、卷叶海鞘)，1972年有另一种(冠脉海鞘，原分枝海鞘)，1983年以来有8种[华南海鞘、丛枝海鞘(原大洋洲海鞘，和爬虫海鞘)]。我们根据历史记录、我们35年的实地考察记录以及我们在1994年秋、1995年春、1996年秋和1997年春进行的最近调查，估计了从圣地亚哥到圣巴巴拉的南加州所有港口中非土著和本地海鞘的相对丰度和季节波动。文中还包括了异类的可能来源和对美国太平洋海岸范围进一步扩大的预测。同时也回顾了本世纪以来南加州港口的本地海鞘数量和种类的减少。
Southern California's many large harbors form an important coastal ecosystem, yet they are also a major destination for thousands of pleasure craft and cargo vessels that have often traveled great distances. Many groups of marine organisms, including ascidians, have now been documented as undergoing range extensions as a consequence of rapid ship-transport between distant harbors phenomenon. This has resulted in a rapid increase in the rate of introductions of non-indigenous species worldwide, yet these effects of boat traffic remain largely unstudied in southern California. Ascidians are sessile marine filter-feeders, hermaphroditic, and often self-fertilizing; many species are tolerant of a wide range of environmental conditions, can reach sexual maturity in just a few weeks, and have a long breeding season. This paper documents the arrival of 14 non-indigenous species in southern California harbors during this century, 13 of which have persisted: four prior to the 1960s (Ciona intestinalis, Styela clava, S. plicata, Botryllus schlosseri), another by 1972 (S. canopus, formerly S. partita), and 8 since 1983 [C. savignyi, Ascidia zara, Ascidia sp., Polylandrocarpa zorritensis, Symplegma brakenhielmi (formerly S. oceania, and S. reptans, Microcosmus squamiger, and Molgula manhattensis)]. We estimate the relative abundance and seasonal fluctuations of both non-indigenous and native ascidians in all harbors in southern California from San Diego to Santa Barbara based upon the historical record, our 35 yr of field notes, and our recent surveys carried out during fall 1994, spring and fall 1995, fall 1996 and spring 1997. Possible points of origin of the exotics and predictions on further U.S. Pacific coast range-extensions are included. The concomitant decline in numbers and species of native ascidians in the harbors of southern California during this century is also reviewed .