Presenter: Sandra Dorning
Faculty Mentor: Craig Young
Presentation Type: Poster 58
Primary Research Area: Science
Major: Marine Biology
Funding Source: Undergraduate Research Opportunity Program Mini-Grant, University of Oregon Undergraduate Research Opportunity Program, $1000
Marine fouling communities on docks and other manmade structures are frequently susceptible to invasions of non-native ascidians—sessile, sac-like marine invertebrates. Botrylloides violaceus, the violet tunicate, has invaded such communities in harbors around the world, including Oregon’s Coos Estuary. In this study, I aim to explain the mechanisms behind the invasion and establishment of B. violaceus in this bay. I propose three potential factors influencing the distribution of this species in the Coos Estuary: 1) abiotic conditions (water temperature, salinity, and water current speed), 2) biotic conditions (competitive relationships with other fouling organisms), and 3)
limited transportation between fouling sites. I conducted quarterly photo quadrat surveys to determine the seasonal distribution of B. violaceus, in addition to short-term permanent quadrat and settlement plate monitoring to document B. violaceus growth patterns and interactions with other fouling species. In addition, I conducted laboratory experiments to determine the temperature and salinity tolerance of B. violaceus. Future experiments in this study will include transplantation of B. violaceus colonies for evaluating survival at currently uninvaded sites. The results of this project will document the extent of and mechanisms behind the Coos Estuary B. violaceus invasion. Understanding the interactions between B. violaceus and native fouling organisms and the potential for this species to expand its distribution is important for conserving native biodiversity and improving invasive species management in the Coos Estuary.