SEA Currents: News
April 15, 2015
SEA Professor Co-Authors New Study on Ocean Plastics Trends
Co-author Dr. Kara Lavender Law
The abundance of plastic debris in our world’s oceans has become increasingly well documented, thanks in part to decades of intensive data collection by SEA scientists and SEA Semester students. But determining just how much plastic has entered the ocean, and where it all goes, remains a challenge.
A new study co-authored by Dr. Kara Lavender Law, SEA Research Professor of Oceanography, sheds new light on one piece of this puzzle: Can plastics from the bellies of deceased seabirds provide an accurate sense of pollution levels in a given ocean environment?
There are practical reasons why it’s important to understand this question more fully: Two formal European ecological protection policies are already using plastic levels in seabird stomachs as a way to measure acceptable levels of pollution.
New Insight on Plastics in Seabirds and the Ocean
The study, published online this week and led by Jan A. van Franeker of Wageningen University and Research Center in the Netherlands, compares the findings of two long-term datasets:
- Dutch data from the North Sea measuring the amount of plastic found in the stomachs of beached fulmars, a seabird resembling a gull.
- SEA data documenting numbers of floating plastic pieces collected by plankton nets in the North Atlantic subtropical gyre, where surface currents cause floating debris to accumulate.
Sure enough, their findings indicate that seabird stomach contents are effective at measuring trends in floating plastic debris in the ocean. Although long-term trends in overall plastic abundance are difficult to detect, both datasets clearly showed a 75% decrease in the amount of pre-production plastic pellets since the 1980s.
“The reduction in plastic pellets observed from fulmars in the North Sea, a likely source region of plastic to the ocean, and in the subtropical North Atlantic, where floating plastic ends up, suggests that changes in plastic input to the ocean can be rapidly observed even in the middle of the ocean, “ says Dr. Law. “While we don’t fully understand what ultimately happens to the plastic accumulating in the gyre, once we stop putting new plastic into the sea we should rapidly see an essentially plastic-free surface ocean.”
This study originated from discussions in the Marine Debris working group at the National Center for Ecological Analysis and Synthesis (NCEAS), with support from Ocean Conservancy. Dr. Law is the co-principal investigator of the working group.