Tuesday, February 5, 2008

Following a river of trash in the sea

Our noon position: Latitude 33 45.655 N, Longitude 160 21.999 W

An unexpectedly busy, fairly dramatic day for the ORV Alguita. The day progressed quickly from drifting in the “doldrums”, to discovering a concentrated windrow of trash, to spotting an uncomfortably curious Mako shark on a night dive. Sending several of us flippering high speed back to the boat, and others – namely Jeff, to quickly suit up and jump in for a closer look…

First, back to the windrow, one of the more significant findings of this trip thus far. This morning, after another elaborate breakfast session, (Captain’s on a role – omelettes with fried potatoes, toast and butter, and fried plantains) we looked to busy ourselves on what felt like a slow day. We’re in what’s known as the horse latitudes, an area traditionally avoided by mariners due to sluggish winds. Some cleaning, some boat chores – here’s Anna and Jeff lowering the Genoa sail, and we all sprawled on deck to look for debris.

Charles and Marcus, shown here, stood at the bow ready to net any floating debris, an activity usually resulting in a few synthetic strays here and there – bottle caps, large shards, bits of fishing line, etc. Soon however, they were pulling up large pieces every other minute. We’d happened on a Langmuir windrow , a series of circular counter currents that meet, sweeping mixed layer sub surface materials to the top, into a sort of oceanic river, visible as a slick on the ocean surface. In a perfect world, this would consist mainly of nutrients – plankton, spawn, etc. – attracting seabirds and other marine creatures to feed. This, as you may have guessed, was a waste windrow – a visible line

of floating debris.

According to Charles, this was the second most dramatic windrow he’d ever seen, and the widest yet. Many of the larger pieces showed clear signs of “fouling” – covered with growth, and often gnawed to pieces. Both plastic baskets contained fish, the monofilament drift net with a dozen new banana floats was also, along with lots of pelagic crabs. A five foot piece of 3” diameter tubing that looked like PVC tubing, but was white on the outside and black on the inside and floated (PVC sinks in seawater) once removed, housed a triggerfish that came flopping out onto Jeff.

Herb, stuck manning the helm throughout our bustling debris removal, did a masterful job navigating us towards trash while conflicting directions were shouted at him rapid fire…

Here’s the Captain with our day’s haul, an impressive collection. By his accounts, this debris had been at sea for some time, and based on its growth, had resided at deeper levels. The bottle that was floating on the surface not in a windrow was heavily encrusted with barnacles, but the crates and float parts in the windrow had hairy growths characteristic of deeper debris. Future studies may look at ways to determine the depth at which debris has been residing.

The area would, we thought, make for a perfect night dive – thick with jellies and salps, prime night for a bioluminescence display no thoughts of the fins we noticed trailing us earlier in the day…..

After anchoring and waiting for nightfall, we slipped into the cold waters and watched a rich scene of underwater life – waters thick with unusual creatures – Jeff pulled up a bizarre, conical shaped Pyrosoma atlanticum-tightly packed colonial thaliaceans embedded in a tough, rigid tube, a lantern fish, and a leaping shrimp. And Joel mentioned spotting a large fish. Which turned out to be a Mako Shark. The last thing any of us expected to see…..and clearly interested in checking us out! Joel actually kicked it away, as Anna, Herb and Marcus made a beeline for the boat.

Safely back on board, we’re all now reflecting on the magnitude of what we’ve seen today. Though the windrow discovery generated some high excitement it also elicited a dose of disgust, and brought up some questions about how far throughout the water column debris is dispersed.

Tomorrow we’re back on our due east course, expecting a quieter day of travel, but one never knows what the gyre will bring…..

Aloha and cheers from the Captain and Crew of ORV Alguita!


Hermanita de Anna said...

Can you please let us know if your trip is being extended given the new research opportunity? We were unsure after the last message... Some uneasy parents want to know...

Clif said...

what do you do with all the plastic junk you collect? It looks like you are gathering enough to take up quite a bit of room onboard and I can't imagine it gets tossed back in the water.

JEM said...

I docent at Ballona Wetlands and make sure the students see the picture of the albatross with all the plastic. They now know that even a bottle cap is bad to leave in the street. Thank all of you for the most important work you are doing. JEM

Sr. Chief said...

You can't make a Mako Shark into a pet. You are driving your Mother crazy.

Knucklehead said...

I just found you from a link on DK.
I`ve been reading as much as I can find on these gyres of trash since a five part series in the LA Times a few years ago.
I`ll be visiting here often. It`s hard to believe the increase in size of these two patches. A few years ago, I suggested that factory ships powered by solar could start chewing this plastic up & formed into ingots that could be brought back to shore. At some point in the future I believe that it will be profitable to do this, as the cost of not removing it & preventing this kind of natricide ( I just made a word for the homicide of nature) will be even greater. You can see some of my reef specimens at my blog here.

Kaisa said...

Why were you so surprised to see a Mako Shark? What is the most intriguing/interesting animal you've seen thus far?

West Lafayette High School
Grade 9