Beachcombing Science from Bath Toys

by Curtis C. Ebbesmeyer

Twelve years and counting — the saga of the tots’
tub toys continues. On January 10, 1992, 28,800 turtles, ducks, beavers and frogs packed in a cargo container — called Floatees by the manufacturer — splashed into the mid-Pacific, where the 45th parallel intersects the International Date Line (44.7°N, 178.1°E). During August- September, 1992, after 2,200 miles adrift, hundreds beached near Sitka, Alaska. Twelve years later, in 2004, beachcombers were still ?nding the bath-time critters.

At Sitka’s second annual beachcomber fair held on
25 July 2004, Dean Orbison and son Tyler Orbison, 22, exhibited a hamper full of 111 toys they’d beachcombed nearby Sitka during 1993-2004. The basket held comparable numbers: 18% turtles, 35% ducks, 26% beavers, and 21% frogs. During years at sea, the ducks and beavers faded to white while the turtles and frogs remained original blue and green, respectively. Animal bites and the surf smashing them against rocks had ruptured many.

Through the years, Dean patiently recorded the date and location where they found ninety of the fist-sized toys.

Dean Orbison with turtles, ducks, beavers, and frogs.
After 12 years adrift, the frogs and turtles remained true-blue to their original colors (green and blue, respectively), whereas the ducks and beavers faded from yellow and red to white, respectively. Dorothy Orbison photo

This astonishing record reveals peak recoveries in five years with intervening gaps of 2, 4, 3, and 3 years, i.e., 1992–1994–1998–2001–2004. Each year, Dean and Tyler conducted comparable beachcombing effort so the
peaks in the time line are not the result of differing times spent along the shore. The first peak occurred before
the Orbisons began recording, but a year in which other beachcombers reported hundreds. We may safely assume an initial peak in 1992, the year the playthings first invaded Sitka.

Jim Ingraham’s computer simulation of ocean surface currents known as OSCURS (Ocean Surface CURrent
Simulator), provides an understanding of the peaks in toy recoveries. OSCURS applies because its trajectories
around the North Pacifc Subpolar and Subtropical gyres have compared well with those of many drifters, including numerous satellite-tracked buoys, migrating salmon and a sea turtle, many MIBs, several derelict vessels, hundreds of Nike sneakers and hockey gloves, and the floatees.

After the tub toys first arrived in Sitka, flocks headed west along coastal Alaska and the Aleutian Islands where
— 3,500 miles from the spill — hundreds invaded Shemya, as reported by Chrystle White. Many continued
on westward to Kamchatka, Japan, then redoubled the Pacific back to Sitka completing the 6,800 mile loop around the Pacific Ocean’s northernmost gyre, the North Pacific Subpolar Gyre (hereafter the Gyre).

OSCURS demonstrated the tracks the toys took, rounding the Gyre to Washington, where Karen Gerber
and Verne Krause recovered a turtle and duck, respectively. In the Queen Charlotte Islands, Guthrie Schweers found two turtles and four frogs. Remarkably, after three years, all three beachcomber finds agreed with OSCURS trajectories around the Gyre.


Subpolar and Subtropical Gyres of the North Pacific Ocean. Heavy lines, average drift path; small arrows, local currents; dots, Great Garbage Patch. Currents carry drifters along the heavy lines around the Subpolar Gyre in three years, and around the Subtropical Gyre in six years. Flotsam may circulate in the Garbage Patch for half a century.

The Orbison data indicate that flocks of toys completed four orbits of the Gyre. The first (2 years) may be faster
than the latter three (4, 3, 3 years), because the toys developed holes but continued floating full of water buoyed
by the low specific gravity of their plastic.

Historic MIBs — Messages In Bottles — provide confirmation of the Gyre’s orbital period as evident in the Orbison time series. In the 1950s, into the Gulf of Alaska Canadian oceanographers hurled 33,869 MIBs in
12-ounce brown beer bottles. Twelve drifted around the Gyre in 1.9-4.2 years, matching the interval between the Orbison peaks (2-4 years). The toys, plus MIBs, provide twenty estimates, indicating the mean time to orbit the Gyre equals 2.9 years. As to speed, the mean orbital period equates to 6.9 miles per day over the 6,800-mile course around the Gyre.

Dean and Tyler beachcombed an important contribution to oceanographic science. The toys provide 40% of
the orbital period estimates and the MIBs the remaining 60%. How many more trips around the Gyre will the toys make in future years? After four circuits, by mid-July 2004 Dean and Tyler found four toys; Kim Elliot located a faded blue turtle. The Orbison data show numbers decreasing six-fold in a decade from 25 in 1994 to four in 2004.

Prior to the Orbison data, OSCURS had suggested that the Subpolar Gyre could trap flotsam like its neighbor
to the south, the North Pacific Subtropical Gyre, famed for its Texas-sized garbage patch. In 2003, beachcombers found flotsam half a century old — a rubber ball and two glass fishing floats — which had been circling the Subtropical Gyre for as many as eight circuits. The Orbison data indicate flotsam wheeling round the Subpolar Gyre for up to four circuits. I wonder if Floatees will appear through five Gyre rotations, with a fifth peak anticipated in 2007?

What became of the thousands of toys beachcombers never reported? Some, the surf buried and others spun out of the Gyre. According to OSCURS, the currents transported a number through Bering Strait into the Arctic Ocean, where the pack ice conveyed them onward over the
North Pole into the North Atlantic Ocean. Bethe Hagens observed a duck in Maine (July 2003); and Sonali Naik observed a frog in Scotland (August 2003). These drifts agree with a score of historic transarctic drifters, including bottles, barrels, and plastic drift cards.

Other toys spun out of the Subpolar Gyre south into the Subtropical Gyre where Lucy Keith recovered a turtle
(Kure Island; July 1996), and Walt Pich reclaimed a beaver and frog (Lanai Island; March 1997). Under the tropical sun, many disintegrated to plastic sherds of the size displayed by Richard Lang and Judith Selby on the cover of this Alert. Ultimately, the toys will turn to dust, joining the scum of plastic powder which rides the global ocean.

I thank Mary Ann and Larry Calvin for putting me up for a week for the Sitka Beachcombers’ Fair, Larry for taking me and 12 other scientists aboard the Morning Mist to beachcomb Fred’s Creek, and Nancy Davis for thoughtful reviews of this article. The Fair continues to be a major feature at the Paths Across the Pacific Conference. The next meetings are scheduled in Sitka for July 20-26, 2005, with the Beachcomber’s Fair held on Sunday, July 24. MIBs: Hollister, H.J., and A.J. Dodimead, 1962. Canadian drift bottle releases and recoveries in the North Pacific Ocean. Fisheries Research Board of Canada, Manuscript report series (oceanographic and limnological) No. 141, October 22, 1962. Statistical notes: time to drift around the Gyre equals 6,800 nautical miles divided by the speed between the drifter’s start and ending observed time and position. Speeds between start and end points: 20 estimates; mean = 6.93 mpd; standard deviation = 2.06 mpd; coefficient of variation (standard deviation/ mean) = 0.30. Time to complete a single-circuit around the Gyre (6,800 nautical miles): 20 drifters; mean = 2.93 years; standard deviation = 0.86 years; coefficient of variation = 0.29; 95% confidence limits on the mean = ±0.40 years (there’s 95% certainty that the mean lies between 2.5-3.3 years); median = 3.0 years; range = 1.9-4.5 years.