Invasive species in Alaska waters are focus of grad student’s work on Smithsonian project
APU graduate student Danielle Verna, MSES ’13 and a Graduate Fellow with the Smithsonian Environmental Research Center, is working with a team of SERC scientists studying ways that marine species hitch a ride in the ballast water of oceangoing ships.
“Given the right conditions, non-native species like some crabs and sea squirts have potential to become invasive in coastal Alaska waters, raising biologic, economic and social concerns,” Verna told the APU Blog.
Verna is a Coast Guard Academy graduate pursuing her degree with APU Assistant Professor Brad Harris in APU’s Applied Fisheries Science Lab.
“Danielle is a perfect example of the blend of experience and academic excellence that our students bring to Alaska-based problems and opportunities,” Harris said. “Ballast water management is critically important to maintaining healthy marine ecosystems in Alaska.”
Ballast water as a vector for invasive species is a growing concern in Alaska, where more ships – and increased risks of non-native species – are anticipated with the opening of the Arctic to vessel traffic.
Compared with other regions, Alaska so far sees relatively few invasive species. Verna says that studies such as the one she took part in add to understanding of current conditions and potential risks.
Verna and the SERC team conducted ballast water biology studies at different U.S. ports, including Port Valdez. The site 300 miles east of Anchorage on Prince William Sound is the terminus of the trans-Alaska oil pipeline and serves tankers loading Alaska North Slope crude.
The researchers collected water samples from the ballast tanks of 26 vessels during weeks-long fieldwork from June to September 2012.
“Commercial ships may arrive any time, day or night, so we were prepared for that,” Verna said.
After spending two or three hours sampling a tank, the team hurried to a lab at nearby Prince William Sound Community College to analyze and fix samples, noting the taxa and count of zooplankton in each sample.
Ballast is brought on board for a variety of reasons, including for stability when vessels are traveling without cargo. Current regulations call for ships to dump coastal water taken on at one port and replace it with open ocean water before arriving at the next port.
Verna said that a goal of ballast water management is to limit the introduction of non-native species, especially coastal organisms like clams, urchins and worms that are more likely than oceanic organisms to survive at a receiving port. Valdez samples contained crab larvae and numerous species of copepods, among other organisms.
A key finding of the Valdez study concerns the type of organisms collected: Significantly fewer coastal organisms were found in tanks that had been exchanged for open ocean water, Verna said.
“Ballast water exchange is an important step forward to reducing invasion risk,” Verna and SERC co-authors Drs. Kim Holzer and Jenny Carney concluded in a feature story published in January by the Marine Invasions Research Lab.
Verna’s MSES thesis, which incorporates Valdez fieldwork, examines general ballast water management practices of vessels arriving in Alaska from 2004 to 2011. Her research includes a risk assessment of invasive species at Alaska ports.