Editor's Note: Scuba instructor and underwater videographer Drew Wheeler is traveling on board the Algalita Marine Research Foundation's 50-foot (15.2-meter) Ocean Research Vessel, Alguita, on a two-month voyage to sample and study portions of a 10-million-square-mile (25.9-million-square-kilometer) oval known as the North Subtropical Gyre (aka "Pacific garbage patch"). Wheeler and the rest of the Alguita crew left Long Beach, Calif., on June 10 with a plan to cross the International Date Line and investigate regions of reported high plastic concentrations, northwest of the Hawaiian Islands. This is his second blog post for ScientificAmerican.com.
June 22, 2009
Over 2,000 miles (3,218.7 kilometers) traveled.
Despite having plans changed by the poor wind of week one, week two has been a bit more eventful.
Once we decided to take on the task of sampling the area indicated by NOAA Coastal watch, (see previous installment of Wheeler's blog) we set a course almost due west. With brisk trade winds, we had some fun days of solid sailing with just the spinnaker flying. We had gusts up to 30 knots (34.5 miles per hour) and the Alguita scooted along at 14 knots (16.1 miles per hour). We made such good time that Capt. [Charles] Moore decided to stow the chute and run with the main and staysail up to slow us down so we wouldn't arrive on location in the middle of the night. It's never fun to set trawls at 2 a.m.
There was a brief moment of excitement on Saturday afternoon (June 20) when a black-footed Albatross snagged itself on one of our trolling fishing lines. Fortunately, the line—not a hook—caught one of its wings. Once we got the bird on board, we freed the wing and returned it to the sea. The last we saw, it was attempting to take off with an awkward run across the water.
We arrived at the start of our trawling transect location on Sunday. Our plan was to trawl a cross section of the bloom area in two-hour increments, so we get a good gradient of results as we pass from lower to higher concentrations and vice versa.
We ran our trawls all day and into the night despite the increasingly rough sea conditions. Our best estimate was that we were working in Force 6 winds, according to the standard Beaufort scale, or 25 to 30 knot (28.8 to 34.5 miles-per-hour) winds and nine to 12-foot (2.7 to 3.7-meter) seas.
We had more than half a dozen trawls completed when disaster struck. Around midnight First Mate Jeff Ernst saw the top towline get taught and the Manta plunge below the surface. The Manta trawl is designed to skim the surface, while being pulled by a control line that attaches to the base of the opening.
However, there is a towline, affixed to the top of trawl, used to retrieve it. That towline must remain slack or the manta will dive under the water. When a tangled knot got caught on a deck block, the towline went taught and the Manta plunged underwater. The large swells snapped a bracket for the towline on the aluminum-framed trawl, putting all the forces upon the control line and the "J" bar on the boat. We scrambled to regain control of the trawl before losing it to the ocean depths. Jeff and Joel [Paschal] struggled to get the control line around a winch and start pulling the trawl on board.
It was very close; we almost lost the whole trawl overboard. The J bar, that incidentally holds the entire radar navigation system, bent aftward about two-to-three inches (5.1-to-7.6 centimeters), snapping the lifelines like twigs and almost broke free of the deck.
At that point I ditched the camera and somehow Jeff, Joel and I got the Manta back on board. Still, the trawl was badly beaten up, with the float wings bent on both sides and the top tow connector sheared off, it was obvious that our beloved Manta trawl was out of commission for a while.
We made the best of it and used the education sample net and the bongo trawl and to gather some samples.
We plan to do a few more trawls near the end of the bloom transect then throw up some canvas and ride the trades to Honolulu for repairs.
Fortunately, as Captain Charles Moore said, "Nobody got hurt and all the gear can be fixed." When I look back at the video and pictures of that night, I completely agree.
The journey continues…
Images © Drew Wheeler