RUI: Experimental Seawater Laboratory at the Coastal Studies Center, Bowdoin College

Bowdoin College, Brunswick ME

Investigators

Abstract

The Bowdoin College Coastal Studies Center (http://www.bowdoin.edu/coastal-studies-center/) is awarded a grant to expand the capabilities of an existing flowing seawater system so that climate variables can be independently manipulated in experimental aquaria. The Coastal Studies Center (CSC) on Orr's Island in mid-Coast Maine, is an educational and research laboratory serving Bowdoin College and visiting students and researchers. The CSC has a sentinel position at the southern boundary of the Gulf of Maine, a cold-water boundary that is moving northward as the Earth's climate warms. Further, the once highly productive Gulf of Maine faces other synergistic impacts including overfishing and invasive species that are changing the structure and function of kelp forests, the rocky intertidal, seagrass beds, and salt marshes. While several research-focused marine laboratories rim the Gulf of Maine, the CSC is a unique RUI focused center that is focused on facilitating undergraduate engagement on the problems of a rapidly changing ocean. This project improves the RUI capabilities of Bowdoin College, which has significantly increased female and minority enrollment over the last ten years. The new experimental seawater capabilities are also likely to attract new visiting students and faculty, expanding the CSC research community. Finally, the improvements will allow increased experimentation and monitoring of estuarine systems. Estuaries support high biological productivity, yet they also experience stronger and more variable impacts of ocean acidity than the open ocean due to the reduced buffering capacity of freshwater inputs and high biological contributions of carbon dioxide. A new cluster of sensors will sample key climate change variables (including crucial pCO2) in Harpswell Sound and stream this data to Internet portals year round, providing a much-needed estuarine node in the Gulf of Maine. The project has two major elements: 1. building four experimental seawater modules that will independently control temperature, oxygen levels, pH, and sterilize effluent; and 2. constructing a pier-mounted instrument array to continuously monitor climatic variables. Element 1 includes a seawater cooling system that combines an external centralized chilling unit with four independent chilled water loops (modules) that can cool 400 gallons of seawater from summer ambient temperatures to 4 degrees Celsius. Additionally, each module will be fitted with the plumbing, controls, and sensors to manipulate dissolved oxygen levels and pH via addition of nitrogen and carbon dioxide gasses respectively. An inline UV filter system will be added for experimental applications that culture non-native organisms and require effluent sterilization. Element 2 will install a pier-based environmental monitoring platform, that will stream temperature, salinity, pH, and pCO2 data to a global research community 365 days a year. This new monitoring location in Harpswell Sound will provide key environmental data on how estuarine marine systems are responding to climate change, and provide essential data for parameterizing climate change experiments.