Here are answers to questions that people have asked us about our drift card study.
Q. How will the cards be released?
A. Approximately once a month for the next two years (winter 2002 - winter 2004), a volunteer team will travel to a location between the mooring buoys located about a mile offshore of Barber's Point. Each time, the team will release a batch of 100 cards into the water. A total of 2400 cards will be released during the 2-year period of this study.
Q. Why will the cards be released each month instead of all at once?
A. Winds and currents usually shift speed and direction as the seasons change, so cards released during different seasons of the year may drift to very different places. We will be releasing cards approximately once a month to get an idea of the distribution of card drift under different environmental conditions.
Q. Will you release each batch of cards at the same point in the tide cycle?
A. No, we are not coordinating the card releases with the tides. We are guessing that the variations in the winds and non-tidal currents will dominate the movement of cards over the several days it will take for the cards to come ashore.
Q. When will you release the cards?
A. We've released cards on these dates, and will continue to release them about once a month for two years.
Q. Why is Barber's Point of special interest?
A. Barber's Point is of interest for two reasons: (1) There are complicated tidal effects offshore of Oahu. This is an area where currents are highly variable and difficult to predict with any certainty. (2) The location between the Barber's Point mooring buoys is a good fixed point that can be returned to month after month. Should someone wish to repeat or extend this drift card study five years from now, we would expect that the moorings would still be there.
Q. What does a drift card look like?
A. Our drift cards are thin pieces of wood, about 4 inches [10 cm] wide by 6 inches [15 cm] long, coated with orange, non-toxic paint. Here is a picture (16K PDF file) of one of them.
Q. Won't your experiment contribute to the problem of trash on our beaches?
A. The worst beach trash problems are items like plastics, or things that take a very long time to biodegrade. In contrast, our drift cards are made of thin pieces of wood, coated with a non-toxic paint, and are specially designed to biodegrade within a few months in the marine environment. As we run our study, we are careful to comply with relevant laws and regulations, especially MARPOL Annex V (33 CFR 151), which was intended to protect our oceans and coasts from trash and garbage.
Q. How many cards from each batch do you expect to be found and reported back to you?
A. We're expecting to get back approximately 5 to 10 reports from each batch.
Q. What does the date when a card is found tell you?
A. It does not tell us how long it took the card to float from the Barber's Point mooring buoys to the location where someone found it, since the card might have remained on the beach for some time before someone noticed it. It does tell us the maximum length of time it took for the card to get to that location, and generally gives us some idea of how long it might take for floating material to travel from Barber's Point to that location.
Q. What if people find a lot of cards at a particular location?
A. That finding might indicate that the location is a "collection beach," at least at some times of the year. A collection beach is a coastal location where floating materials--driftwood, Styrofoam products, our drift cards, and potentially floating pollutants--naturally collect. In the event that our drift cards identify a "collection beach," we would repeat our experiment, releasing more cards to see if we obtain the same result. We would also ask local residents whether the area is known to be a collection beach.
Q. Why did you choose to use drift cards?
A. Drift cards are inexpensive devices that allow us to do a small study over a broad range of environmental conditions and over a fairly long period of time. Using these drift cards also allows us to take advantage of volunteer assistants!
Q. How can I contact you to tell you where I found a drift card? The card I found is too "weathered" to read.
A. There are several ways to let us know about your find:
NOAA HAZMAT Drift Card Study
7600 Sand Point Way NE
Bldg 3 / N-ORR1
Seattle, WA 98115
Q. How well do the drift cards simulate floating pollutants and debris?
A. The movement of a floating object is controlled, in large part, by how much of the object is out of the water and how much is under the water. This determines how much the wind will blow the object downwind. No one (that we are aware of) has studied drift cards to see how they compare with floating pollutants or debris, such as Styrofoam cups, driftwood, paper, etc. One thing we can compare is the density of our drift cards with the density of some oil products.
Q. What will the results of this study prove?
A. This is an "exploratory study." It's meant to give us an idea of where we should direct our efforts in future studies. We expect to see a trend of where floating materials might go if released from the south shore of Oahu.
