Distribution and diversity of tunicates utilizing eelgrass as substrate in the western North Atlantic between 39° and 47° north latitude (New Jersey to Newfoundland)

Management of Biological Invasions
Mary R. Carman; Philip D. Colarusso; Eric P. Nelson; David W. Grunden; Melisa C. Wong; Cynthia McKenzie; Kyle Matheson; Jeff Davidson; Sophia Fox; Holly Bayley; Stephen Schott; Jennifer A. Dijkstra; Sarah Stewart-Clark
By: , and 

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Abstract

Seagrass meadows are ecologically important habitats that are declining globally at an accelerating rate due to natural and anthropogenic stressors. Their decline is a serious concern as this habitat provides many ecosystem services. Eelgrass (Zostera marina) is the dominant seagrass species in the western North Atlantic. It has recently been established that invasive tunicate species possibly threaten the health of eelgrass beds. Colonization of eelgrass leaves by tunicates can inhibit eelgrass growth and may cause shoot mortality. To document the distribution and diversity of tunicate species that attach to eelgrass in the western North Atlantic, we surveyed twenty-one eelgrass sites from New Jersey to Newfoundland. Eight species of tunicates were found to be colonizing eelgrass, of which 6 are considered invasive. Botrylloides violaceus and Botryllus schlosseri were most commonly attached to eelgrass, with B. schlosseri having the largest latitudinal range of any species. Tunicate faunas attached to eelgrass were less diverse north of Gloucester, Massachusetts, where individual survey sites exhibited two species at most and only 4 of the 8 species observed in this study. Percent tunicate cover on eelgrass tended to fall within the 1–25 range, with occasional coverage up to >75–100. Density of eelgrass was highly variable among sites, ranging from <1 to 820 shoots/m². The solitary tunicate Ciona intestinalis was only found on eelgrass at the highest latitude sampled, in Newfoundland, where it is a new invader. The tunicates observed in this study, both solitary and colonial, are viable when attached to eelgrass and pose a potential threat to overgrow and weaken seagrass shoots and reduce the sustainability of seagrass meadows.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Distribution and diversity of tunicates utilizing eelgrass as substrate in the western North Atlantic between 39° and 47° north latitude (New Jersey to Newfoundland)
Series title Management of Biological Invasions
DOI 10.3391/mbi.2016.7.1.07
Volume 7
Issue 1
Year Published 2016
Language English
Contributing office(s) Patuxent Wildlife Research Center
Description 7 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Management of Biological Invasions
First page 51
Last page 57
Country Canada, United States
Online Only (Y/N) N
Additional Online Files (Y/N) N