見于北美大西洋沿岸的海洋入侵物種巖藻（Fucus serratus）和歐洲玉黍螺（Littorina littorea）很可能是在19世紀(jì)跟隨英國和愛爾蘭船只而來到這里的,。那時(shí)候，跨大西洋的船只通常使用巖石作為壓艙物,，這些壓艙物在港口或沿岸淺水區(qū)被拋棄,。
Susan Brawley及其同事提出，這種傾瀉壓艙物的方式很可能也把這兩種海洋物種引入了加拿大的沿岸地區(qū),。巖藻持續(xù)在加拿大沿岸擴(kuò)散,，而歐洲玉黍螺已經(jīng)向南推進(jìn)到了特拉華州的沿岸。這組科學(xué)家對來自新斯科舍省Pictou 港的當(dāng)代巖藻和歐洲玉黍螺樣本進(jìn)行了一次遺傳分析,，,，結(jié)果顯示它們和來自蘇格蘭和愛爾蘭的巖本相匹配，這兩個(gè)地區(qū)與Pictou有頻繁的貨運(yùn)聯(lián)系,。
這組作者發(fā)現(xiàn),，巖藻表現(xiàn)顯出的自主擴(kuò)散的本領(lǐng)有限，它們分別從愛爾蘭的Galway和蘇格蘭的Greenock到達(dá)了新斯科舍，而且這組作者把新斯科舍的歐洲玉黍螺和見于愛爾蘭和蘇格蘭的物種的遺傳指紋聯(lián)系了起來,。這組作者認(rèn)為巖藻和歐洲玉黍螺在北美的引入是“入侵的冰山一角”,，并且提出這類入侵物種新的到來可以對海洋生態(tài)系統(tǒng)產(chǎn)生廣泛的影響。（生物谷Bioon.com）
生物谷推薦原始出處：
PNAS May 4, 2009, doi: 10.1073/pnas.0812300106
Historical invasions of the intertidal zone of Atlantic North America associated with distinctive patterns of trade and emigration
Susan H. Brawleya,1, James A. Coyerb, April M. H. Blakesleec, Galice Hoaraub, Ladd E. Johnsond, James E. Byerse, Wytze T. Stamb and Jeanine L. Olsenb
aSchool of Marine Sciences, University of Maine, Orono, ME 04469;
bDepartment of Marine Benthic Ecology and Evolution, Center for Ecological and Evolutionary Studies, University of Groningen, 9750 AA Haren, The Netherlands;
cMarine Invasion Laboratory, Smithsonian Environmental Research Center, 647 Contees Wharf Road, Edgewater, MD 21037;
dDepartment of Biology, Université Laval, Québec, QC, Canada G1V 0A6; and
eOdum School of Ecology, University of Georgia, Athens, GA 30602
Abstract
Early invasions of the North American shore occurred mainly via deposition of ballast rock, which effectively transported pieces of the intertidal zone across the Atlantic. From 1773–1861, >880 European ships entered Pictou Harbor, Nova Scotia, as a result of emigration and trade from Europe. The rockweed Fucus serratus (1868) and the snail Littorina littorea (≈1840) were found in Pictou during this same period. With shipping records (a proxy for propagule pressure) to guide sampling, we used F. serratus as a model to examine the introductions because of its relatively low genetic diversity and dispersal capability. Microsatellite markers and assignment tests revealed 2 introductions of the rockweed into Nova Scotia: 1 from Galway (Ireland) to Pictou and the other from Greenock (Scotland) to western Cape Breton Island. To examine whether a high-diversity, high-dispersing species might have similar pathways of introduction, we analyzed L. littorea, using cytochrome b haplotypes. Eight of the 9 Pictou haplotypes were found in snails collected from Ireland and Scotland. Our results contribute to a broader understanding of marine communities, because these 2 conspicuous species are likely to be the tip of an “invasion iceberg” to the NW Atlantic from Great Britain and Ireland in the 19th Century.
