Science Serving Maryland's Coasts

James Saunders Jr., Hampton University

Class Year: 
2009

Project Title: 

Salinity Tolerances of Fouling Organisms and its Implications for Ship Hull Invasive Species

Abstract: 

International shipping is critical for transporting goods around the world but commercial vessels are also known to be a major vector for aquatic invasive species. While solutions to ballast water invasive species have been studied extensively for over 20 years, ship hull fouling has received relatively little attention and there are few solutions beyond specialized coatings. This study explores the option of low salinity exposure as a means to remove fouling organisms on the hulls of ocean-going vessels thus minimizing the risk of hull fouling invasive species. A laboratory experiment was conducted exposing high salinity (32 psu) fouling organisms found in the coastal bays of the Chesapeake Bay region to either (1) an immediate drop in salinity to 5 psu, remain for 24 hours and then an immediate return back to 32 psu, or (2) a slow reduction in salinity to 5 psu and slow increase back to 32 psu, mimicking a vessel's voyage from the Atlantic Ocean up to the Port of Baltimore, then back down the Chesapeake Bay to the ocean. While significant mortalities were found, no significant difference existed between the rapid and slow salinity treatments and some taxa of fouling organisms appeared to withstand low salinity exposure. Although transit into low salinity water by ocean going vessels could kill some hull fouling organisms thereby reducing the risk of invasive species, this approach would not eliminate the problem.