Over the years, NOAA's Office of Response and Restoration (OR&R) and other NOAA offices have used drift cards--originally plastic but now thin, biodegradable pieces of wood, colored with bright non-toxic paint--to learn more about the direction of ocean currents in a particular region. On the cards are instructions asking the finder to report the date and location found.
Drift cards are often released as part of an oil spill response exercise or drill. Our goal in releasing the cards is to gather information about the possible drift of an oil spill. Drift cards can also indicate where other things, such as stricken fishing boats, marine debris, plankton, or even sewage, might drift.
Drift card studies have a number of benefits to us. They are inexpensive, allow us to do a small study over a broad range of environmental conditions and over a fairly long period of time, and give us the advantage of volunteer assistants!
From 2002 to 2004, OR&R scientists conducted an exploratory study to learn more about the direction of ocean currents off Oahu, Hawaii. The purpose of the study was twofold: to find a trend in where floating pollutants might go under different environmental conditions, if released from the south shores of Oahu, and to give us an idea of where we should direct our efforts in future studies.
About once a month, volunteers from the oil spill cooperative, Clean Islands Council, released a batch of 100 cards from Barber's Point, near Honolulu. We also released several sets of special cards during Kona wind events. These events, with winds from the south and southwest, usually occur several times during the winter months in Hawaii and have the potential to carry pollutants to the Waikiki and Diamond Head areas.
Safe Sanctuaries (Florida)
In 2005, a drift card release was one component of the pollution response drill, Safe Sanctuaries 2005 [PDF, 283 KB]. We designed the study to model floating pollutants in the Florida Keys National Marine Sanctuary, where the drill took place. In this exercise, OR&R and its co-lead, the National Marine Sanctuary Program, worked closely with partners in NOAA, the U.S. Coast Guard, and Florida State Department of Environmental Protection to exercise their emergency response capabilities and to provide training. (You can learn more about this event in the video, Safe Sanctuaries 2005: Emergency Response Drill. Drift cards are discussed at about 10:30.)
Safe Seas (California)
The following year during the Safe Seas 2006 oil spill–preparedness exercise, we simulated spilled pollutants by releasing hundreds of drift cards at the site of hypothetical spills west of San Francisco. The results of this study are available on an earlier, archived version of our website. Our drift card FAQ answers many of the questions that people have asked about drift card releases, and the U.S. Geological Survey has more information and photos from the drill.
More Information about Drift Card and Ocean Studies
The Threat of Humboldt County’s Spartina Population to Other West Coast Estuaries [PDF, 1.4 MB]: This Portland State University research team used drift card releases from Washington state and California bays to help model the potential spread of an invasive marsh grass, Spartina, to Oregon estuaries. More information is available in the Spartina Dispersal Study: Drift Card Release FAQ [PDF, 87 KB].
Using Oceanographic Linkages to Guide Marine Protected Area Network [PDF, 489 KB]: Scientists have used drift cards to infer the movement of larvae of various marine species in the waters off northwestern Washington state to aid in planning networks of Marine Protected Areas.
Flotsametrics and the Floating World: Retired oceanographer Curt Ebbesmeyer operates the Beachcombers Alert, an international network of beachcombers who gather and interpret traceable flotsam (floating trash). For some NOAA drifter releases that are no longer funded, NOAA has entrusted Dr. Ebbesmeyer as keeper of the drift card records. He can be reached through the Contact section of the Flotsametrics site.
Video: Adopt a Drifter: Scientists can also collect and analyze ocean data by using larger, more sophisticated drifting buoys. Through the NOAA Adopt a Drifter program, kids help deploy "drifters" from ships at sea to learn about ocean currents in real time.
Drift Cards in the News
Found: World's Oldest Message in a Bottle, Part of 1914 Citizen-Science Experiment: A Scottish fisherman has found the world's oldest message in a bottle--98 years old, cast into the ocean by a scientist at the Glasgow School of Navigation, who was studying the currents in the North Sea.
After Floating Around in the Atlantic for 26 Years, NOAA Drift Card Comes Ashore on Irish Beach: A small yellow plastic card released off the East Coast of the U.S. was found on a west Ireland beach in summer 2003, after spending 26 years floating in the North Atlantic Ocean.
Alaska boy finds plastic card 33 years after it was set afloat: A plastic drift card, released near Kodiak, Alaska, from a NOAA vessel in May 1979, was one of thousands NOAA sent into the waters around Alaska in the late 1970s and '80s. Almost exactly 33 years later, a 12-year-old boy spots the card among some drift logs on a beach at Sealion Cove.
40-year-old experiment still lingers in the North: An oil field supervisor on Alaska’s North Slope, working at an annual cleanup day in July 2011, found a small, yellow plastic disc on a nearby creek bed. Scientists 30 years ago tossed the disc into the sea as part of a study on Arctic oil spills.
Interesting Find from the Cleanup - A Drift Card: A NOAA drift card, released in July 1979, was found on the Padre Island National Seashore south of Corpus Christi, Tex. in 2011 by a volunteer in the 16th Annual Billy Sandifer Big Shell Cleanup.