Showing posts with label drifters. Show all posts
Showing posts with label drifters. Show all posts

Thursday, June 2, 2011

Look What the Current Dragged In, Part III

Last year I spent a couple posts (first and second) looking at how ocean currents move in my little corner of the world. I learned that Saco Bay is fed by the Labrador Current from the northeast. Which explained why Canadian lobster trap tags and claw bands sometimes wash up on my shore.
Recovered today, after a 150+ mile trip
Those studies taught me that the complex Gulf of Maine is really, in an elegant term I just saw, a "Sea Within a Sea." A system of mini-gyres, upwellings, deep basins, river outflows that comes together to make a rich & vibrant ecosystem all its own. I also learned about the wealth of resources available to a budding Flotsam Diarist in trying to make sense of it all. So when today's walk along the beach revealed a minor mystery, I knew where to turn.

What was the mystery? A batch of lobster claw bands, all but one of them absolutely pristine. Soft, supple, full, unscuffed, unbitten. Including the far-traveling "Wild Canada" band.
Only 1 of the 8 was old & battered (back right)
In my year at Bay View, I've never seen so many fresh bands come in at once -- they usually are a mix of new & old, pliable & brittle.

The Canadian band has a cargo of young marine life stuck to its inside, proof that it had actually made the journey by sea. But it, with its friends, was so fresh. How'd it get here so fast?

Enter NOAA's Northeast Fisheries Science Center and its Drifter Program. For nearly a decade, students at Maine universities have been working with NEFSC to release drifters into the Gulf of Maine (and elsewhere -- sometimes far afield), then tracking their motion. The data is delivered real-time, and is accessible to anyone with the Internet. As it turns out, just two weeks ago, a batch of drifters was released from Downeast Maine -- very near to where a Canadian lobster boat could have been fishing, actually. And those drifters are still afloat, and sending their data back. The image below came from the tracking page literally 15 minutes ago!
("Saco Bay" and "Jonesport" notations are my own)
They show the drifters just zipping along SW down the coast. Within a week, the dark blue one had almost entered Casco Bay (just north of Saco Bay). The dark red one hovered at the entrance to Saco Bay briefly just a day or two ago before heading back eastward. Clearly, things like lost claw bands could have made the journey just as fast; and the currents/winds were perfect for getting them into Saco Bay and onto the beach at Bay View. The proof is in the picture.

I may never know precisely where this Canadian lobster band (and its freshly dropped friends) originated. But thanks to the awesome work of a lot of dedicated folks, I can tell you this: When the conditions are right, something dropped 150 or more miles away could wash up to your feet within just a couple weeks. And that's pretty cool to know.

It's a shame that there's litter in the ocean. But if it's there, it would be a worse shame not to try to learn something from it.

Monday, December 13, 2010

Look What the Current Dragged In, Part II

Back in August I wrote a little piece on a curious lobster trap tag that had floated in on the tide. With help from the good folks at the Gulf of Maine Lobster Foundation, I learned that the tag had taken a 200-mile journey from Canada.

Since then, I've recovered many "Wild Canada" claw bands, as well as half of a recycling bin from New Brunswick. The reason for all this Canadian flotsam is simple. Coastal Maine is fed by the Labrador Current, an ice-cold flow that originates on the western side of Greenland, arcs past eastern Canada, and washes down through the Gulf of Maine.

So it's little surprise that Canadian litter reaches Saco's shores. It's also little surprise that, given the complexity of the Gulf of Maine, things sometimes go a bit wacky.
from http://www.nefsc.noaa.gov/publications/
crd/crd0807/images/f8.gif
Occasionally, a Flotsam Diarist stumbles upon the coolest resources to help learn about the world. Take Environmental Monitors on Lobster Traps, an ingenious collaboration between local researchers, universities, and fishermen. Together, they collect live data on surface currents by launching dozens of drifters with GPS transmitters. Here's a good one that was tracked for several months just this summer:
Released May 8 near Portland, ME
Died Sept. 4, Georges Bank, 150 mi E of Cape Cod
Victim of Hurricane Earl
As the eMOLT track above shows, not everything that flows from the north ends up at Bay View beach. Wind & current may just as easily pull it southeast. If so, it can get caught in one of the Gulf of Maine's many small gyres -- vortexes of swirling waters. There, a piece of flotsam may be trapped for years, and eventually flung out in most any direction. (In larger gyres like the infamous Great Pacific Garbage Patch, millions of scraps of plastic debris churn endlessly in a toxic soup. There are five such gyres of swirling trash now recorded in the world's oceans; there is no known way to effectively clean them up.)

So what happens if a piece of Maine or Canada flotsam gets dragged farther and farther southeast?

Take the example of this little guy:
Just an average Maine lobster trap tag
Sometime after 2007, this tag broke free from its trap, and rose to the surface. Bobbing on the waves in the Gulf of Maine, it stumbled into a gyre or two. Mother Nature eventually cast it southeastward. One fateful day, it met the famous Gulf Stream.

The Gulf Stream gets its start in the tropical waters of the Caribbean and southern Florida. It flows northward along the eastern U.S., veering eastward south of Long Island, NY. It rides south of Cape Cod, warming the shorelines of southern New England on its way.* Eventually its tropically-toasted waters cross the entire Atlantic and flow past the UK and Ireland. These isles, even though they lie nearly 10° farther north than Maine, are made temperate by waters originally heated thousands of miles away.

That little red lobster trap tag, still in nearly perfect condition? Found here:
Gower, South Wales, UK
(image snapped from Google Earth)
In early November 2010, beachcomber Rik Bennett was wandering his local shores in southwest Wales, when he came across this tag. Curious, he scanned the Web to see if he could learn anything about it. Eventually, his search brought him to The Flotsam Diaries. And brought this tag's 3,500 mile journey to light!

A wonderful and poignant reminder that the world is a small place. Everything connects, somehow, with everything else. And water -- the ocean -- is the constant. If you treat your part of it well, it will remember. If you treat your part of it badly, it will remember.
from www.oceanmotion.org - another priceless resource
for a budding Flotsam Diarist


* The warm Gulf Stream waters never reach Maine. All we get is the Labrador -- which is why Maine's ocean temperatures rarely break 60 degrees F, even in August. Actually, Saco Bay records the warmest ocean temps in Maine, being fed by the major Saco River, which is heated by the sun as it travels its 134-mile course.