Mark Van Arsdale: Marine Debris, September 22, 2018


NOAA Teacher at Sea

Mark Van Arsdale

Aboard R/V Tiglax

September 11 – 26, 2018

 

Mission: Long Term Ecological Monitoring

Geographic Area of Cruise: North Gulf of Alaska

Date: September 22, 2018

Weather Data from the Bridge

Southeast wind to 20 knots, rain showers, 6-8 with occasional 12 feet seas

59.913 N, 144.321 W (Kayak Island)

 

Science Log

Marine Debris

The wind came up a bit today, and so did the waves, but we are far enough ahead of schedule that the captain and head scientist decided we should take a two-hour excursion to Kayak Island before taking the eighteen-hour trip into Prince William Sound.  The Tiglax has a pretty deep draft, and the waters surround Kayak Island are shallow, so the boat was anchored about a mile off shore.  The waves were pretty mellow when we departed and it was a pleasant zodiac ride to shore.

The ocean side of Kayak Island is as remote as you can get, but it is covered with human trash. Marine debris is not new, fishing lines, nets, and glass floats have been washing up on beaches for hundreds of years, but the issue changed with the advent of plastics in the 1950’s.  Plastic is buoyant, supremely durable, and absolutely ubiquitous in modern human society.

The beach we walked on faces the ocean and the intense energy of winter storms was obvious.  There were logs thrown up to the high tide of the beach that were nearly four feet in diameter.  The rocks on the beach were polished, rubbed free of their edges.  Driftwood pieces were sanded smooth by the energetic action of waves smashing against rocks.  There were all kinds of interesting things to discover, including fresh bear tracks and some rather large piles of scat.  But more than anything else, there was plastic.  Plastic bottles, plastic fishing floats, fishing line, and wide variety of other refuse.  Some of it below the high tide line, and much of it thrown far back into the dense alder and salmon berry bushes above the high tide line.  Labels and lettering indicated much of the debris was from Asia.  Some of it may have been debris from the large tsunami that hit Japan on March 11, 2011, but much of it was just fishing gear lost during ordinary storms or accidents.

The Kuroshio Current

The Kuroshio Current

So how does fishing gear from Taiwan or Japan end up on a remote Alaskan beach?  Currents is the simple answer, specifically, the Kuroshio Current that flows towards the northeast from Japan.  The Kuroshio Current is a swift moving, warm water current, and it pushes debris into the North Pacific Gyre.  A Gyre is clockwise moving merry-go-round of ocean moved by the rotation of the Earth around its axis and by the prevailing winds.  Much of the debris from Asia gets trapped in that Gyre and coalesces into a floating soup of trash known as the Great Pacific Garbage patch. Some of that debris ends up washing ashore on the islands of Northwestern Hawaiian Archipelago, and some of it takes a left-hand turn, getting caught up in the counterclockwise movements of the Gulf of Alaska Current.  Kayak Island sticks out into the Gulf of Alaska like a hitchhiker’s thumb, and does a good job of catching floating debris.

Kayak Island Alaska

Kayak Island Alaska

Marine debris is more than a problem of unsightly litter.  Fishing gear lost in the water keeps on fishing, catching fish, birds, and sea turtles.  Plastic breaks apart into smaller pieces and ends up in the bellies of seabirds, turtles, marine mammals, and fish.  It’s not uncommon to find dead sea birds in the Northwest Hawaiian Islands with bellies completely filled with human trash.  Seabirds don’t consciously eat plastic, but in lower light conditions floating plastic can look like squid or krill.  To a hungry sea turtle, plastic bags and bottles can look like floating jellies and may clog the digestive system of an animal that eats them.  Plastics also concentrate potentially toxic organic chemicals that can work their way up the food chain into the fish and seafood that we eat.

Much to the annoyance of the crew, we picked up some of the larger floats and brought them on board the Tiglax. Larger efforts have been organized to do summer clean-up work on the outer islands of the Prince William Sound, but their efforts are a drop in a very large bucket.  The problem of plastic debris is enormous and in desperate need of a global solution.

Marine debris, Kayak Island.

Marine debris, Kayak Island.

Marine debris, Kayak Island.

Marine debris, Kayak Island.

Marine debris, Kayak Island.

Marine debris, Kayak Island.

Marine debris, Kayak Island.

Marine debris, Kayak Island.

Personal Log

Big Wave Riders

A rainbow visible as we left Kayak Island.

A rainbow visible as we left Kayak Island.

It doesn’t take long for waves to build in the Gulf of Alaska.  Within an hour and a half, the waves had risen to six feet with occasional ten foot monsters cresting just off the beach.  You could see white caps and even a mile away on the beach you could see the Tiglax bobbing up and down.  Marin, our ever-calm skiff driver, told us in a pleasant voice that the ride would be a little bumpy and that we might be “uncomfortable.”  In reality, it was a harrowing fifteen minutes that seemed to take much longer. I was sitting in front of the zodiac and was thrown several feet in the air more than once as we crested waves much larger than our boat. While on the beach I had discovered an intact 500-watt red lightbulb, used as a squid attractor by fishermen in Asia.  We had seen some of these floating on the surface the last few days, and to me it was the perfect piece of marine debris to take back to my classroom.  Unfortunately, that meant I was riding the bucking bronco that was our zodiac with a very fragile piece of glass in my left hand.  As I was getting air going over each wave, I was very conscious of the potential laceration I was risking to my hand or worse to the rubber zodiac.  Somehow we made it back to the boat, light bulb intact.  For the last two weeks, the Tiglax has grown to feel quite small, even confining, but as we approached the boat it seemed gigantic, dwarfing our skiff with its large steel hull crashing up and down in the waves like a giant hammer.  We tossed our bow line to the crew waiting on the back deck and they held us marginally in place as each of us timed our climb up a safety line with a rising wave.  “Don’t jump, take it slow, wait for the next wave if you need to,” said the captain.  The three other passengers on the zodiac did just as instructed.  The last passenger out, I grabbed the safety line with my right hand, but was unable to climb because of the glass treasure in my left hand. I jumped, skidding onto the back deck as if it was home plate, light bulb still in my left hand.

[Postscript: That lightbulb survived a trip across the Pacific Ocean, washing ashore on a rocky beach, and a trip to the Tiglax by a possibly foolish collector.  However, it only survived 24 hours in my classroom, smashed by an unknown student while I was visiting the bathroom.  Just so you know, high school students are rougher than the Pacific Ocean.]

Red Light Bulb Marine Debris

Red Light Bulb Marine Debris

We all managed to get back on board safely.  The experience and training of the crew really showed through.  When asked later if that was crazy, they answered with a casual dismissal, “just another day at the office.”

We got underway in large seas, six to eight feet, with the occasional twelve-footer.  I don’t know the techniques used to calculate such things, but some of those waves were huge.  As we positioned the boat perpendicular to the waves, each dip into a trough sent spray crashing over the bow of the boat.  I went up to the flying bridge, held on tight to a railing, and enjoyed the ride. The waves were wild and beautiful.  The sun occasionally peaked out from the clouds and the seas reflected a diverse assortment of blue and grey hues.

At the end of Kayak Island there stands the sharp cliffs of Point Elias, a lighthouse at its base, and a rock spire called Pinnacle Rock in front of it.  I’ve seen pictures of this place. It’s an iconic Alaskan image.   I felt lucky to be watching it as we rounded the point and headed into Prince William Sound for the last leg of our trip.

Did you know?

The size of a wave is determined by the multiplication of three variables.  The speed of the wind, the duration the wind blows, and the fetch (distance the wind blows.)  Increase any of those three and waves get bigger.  The size of waves can also be impacted by changing tides or currents and the specific topography of a shoreline.

Animals seen today

  • Stellar Sea Lions
  • Sea otter
  • Lots of birds including Haroquin ducks, double crested cormorants, gulls, common murres, and a blue heron

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