Showing posts with label Bongo Trawl. Show all posts
Showing posts with label Bongo Trawl. Show all posts

Tuesday, August 11, 2009

Pacific Garbage Patch Revisit


What I find most disheartening about this report is the complete lack of any visible capability to even begin addressing this problem on an international basis. Everyone is producing the garbage and it is magically finding its way into the sea. It needs a shared funding plan and that plans needs to focus on simple recovery.

Submerged mesh belts can be used to strain the material from the sea water. Such a device can be as wide as can be made and as deep as necessary. It does not have to be continuous. The collected debris would come off continuously into a transport belt or even an augured channel. This is the emulation of a large whale feeding on the debris at its leisure. Once collected, it is a simple next step to compress to the point of fusing all the plastic organics together and expelling remaining biota to produce dense blocks or cylinders.

This material is then safe to either throw overboard or even reprocess.

It is not hard to imagine a vessel collecting 10,000 tons per year. The density implied certainly suggests this level of productivity.

I do not think that we will solve the supply problem easily so long as the need exists and plastic is the cheapest and best technical solution available. In any case, ending supply will not remove the huge debris problem. A system such as I have just described could hugely reduce the problem since it is gathering naturally

So far we have about three or so serious visits to the problem. I would like to see work done on aging all the plastic components. Perhaps by undeserved good fortune all that junk is only several years old. I do not believe that but a half life estimate would be nice to have.



Aug 6, 2009 10:28 AM in


Voyage to the Pacific Ocean's garbage patch: Sadness, anger and a plea to help avoid catastrophic changes in the marine ecosystem


By
Larry Greenemeier in Voyage to the Pacific Garbage Patch

http://www.scientificamerican.com/blog/60-second-science/post.cfm?id=voyage-to-the-pacific-oceans-garbag-2009-08-06&sc=CAT_INNO_20090807

Editor's Note: Scuba instructor and underwater videographer
Drew Wheeler is traveling on board the Algalita Marine Research Foundation's 50-foot Ocean Research Vessel, Alguita, on a two-month voyage to sample and study portions of a 10-million-square-mile 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 eighth blog post for Scientific American.com.

6,714 miles traveled


With less than 200 miles to Honolulu, we are in the final stretch of the 2009 ORV Alguita Dateline Journey, and every one of the crew can now reflect on what they have experienced and the knowledge they have gained.


Personally, I have learned several things on this voyage, some related to the mission of substantiating the vast amounts of plastic in the ocean and others just related to life. You can't spend over 50 days on a 50-foot boat with five other people and come away entirely the same person!


This journey has allowed me to experience everything from the bewilderment and amazement of swimming among the alien life forms that exist and thrive in the most remote location on the planet. To the sadness and anger I feel when I see, first hand, what we are doing to that life, which most people will never lay their eyes upon.


The increase in plastic from the 2002 voyage to now is frightening. In just seven years, it seemed to me that everywhere we went has become a "high-accumulation zone". The amount of tiny fragments and small bits of plastic that I collected and saw, either floating past the boat or in the trawl samples on any given day was flat out disgusting.


Then add that to plastic material I saw in the water intermixed with the billions of planktonic life, and I don't need a scientific study to tell me that it is a serious problem that ultimately will affect all life on this planet. There is NO WAY a passive plankton feeder can filter out the plastic lingering among it's food supply.


My conclusion: we must stop this from getting worse by reducing or eliminating the use of non biodegradable plastic for disposable products and product packaging. If the increasing rate of plastic in the ocean does not change, then I do not see how we can avoid catastrophic changes in the health of our marine ecosystem and, as a result, to human life itself.


Now that is something to think about!

Monday, June 22, 2009

Pacific Garbage Patch

The existence of the Pacific garbage patch and its apparent longevity is naturally troubling however we wish to ignore it and hope it goes away. Except that begs two issues. The plastic itself keeps coming because we have not decided to make all plastics either reasonably biodegradable which in the presence of sea water cannot be a major trick, or alternatively make it dense enough to simply sink and let geological processes complete the task. Ignoring the problem is not a good option.

We also have little sense of the actual lifetimes of the plastics now adrift. There is a lot of small pieces which graphically shows us that most of the material has likely already been mechanically reduced on the beach. How long do these little pieces stand up? I would love to know that the problem is resolved naturally at the level of fines in say five years. More likely, we are talking about twenty years.

The point I wish to make is that we need some real answers. Mother Nature has ultraviolet and oxidation in seawater to throw against the problem and that is pretty potent. It would be a blessing if that were enough. The evidence so far shows us that Mother Nature is struggling.

The question then is that is it possible to mechanically remove the problem in part at least. The short answer is perhaps, but it will certainly cost.

I can envisage a horizontal drum float acting as the upper jaw and a lower jaw below holding a flow through conveyor belt formed from a strong mesh. Behind we have the other end of the fairly short conveyor belt held above water and naturally dropping debris into a recovery trough holding an auger that draws the debris into a compactor. Compacted blocks are then dense enough to dump. I think that is about as simple as it gets. It is all sort of a simulation of a whale. I hope the whales do not try to eat this crap. Operating in the areas of high density, it is plausible that real headway could be made.

Who knows, we may get enough torque of the drum float to drive the conveyor belt somehow. Anyway this becomes an engineering problem whose difficulty may be that the problem is simply too big. Particularly when a net catches material deeper than it capability.

Today, science needs to provide some answers to difficult questions and troubling concerns.

Voyage to the Pacific Ocean's 'Garbage Patch'
By
Larry Greenemeier

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 (a.k.a. "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 first blog post for ScientificAmerican.com.

Well, we are one week into our journey, and already Mother Nature has proved to be the boss. We expected to have a day or two of northwesterly winds. But we thought once we left shore behind, our catamaran would catch the prevailing northeast trade winds and take us to our objective—the international dateline, north of Hawaii.

Not so fast. We had five days straight of almost pure north wind that kept pushing us farther and farther south. At one point Alguita Captain Charles Moore made the famous call, "We can't there from here." So we then started discussing other objectives, finally settling on an area where some plankton are blooming, just northeast of the Hawaiian island chain.

There is a theory that the same current and weather patterns that lead to plankton clouds may also corral the plastics on the ocean surface, so we are going to see if this is the case. According to [National Oceanic and Atmospheric Administration (NOAA)]
coastal watch scientist Dave Foley, there is a bloom occurring as we speak, and we are only a few days away, so we are going for it.

Up to this point we have had three successful trawls of the water's surface, gathering data from a region never sampled before. We found plastic material in all three runs, but at a rather low concentration. The results weren't all that surprising because we are on the outside edge of the Northern Subtropical Gyre. Still, it is disturbing to find plastic in any sample taken in the middle of the Pacific.

I have had two chances to go for quick swims and check out my underwater video system. Both times I followed the captain as he spotted plastic floating beneath the surface and gathered it up with his trusty aquarium net.

We found a piece of a plastic packing band and a fragment of a disposable grocery bag along with other small particles. It is important to note that these plastic pieces were found and recovered from depths deeper than the
Manta Trawl could collect. It will be interesting to see what the bongo trawls will reveal.
The crew is getting along fine, which is a good thing because we are stuck on a 50-foot (15.2-meter) catamaran for the next five weeks. Everyone contributes by pulling watch and assisting with the sampling. Spirits are still high despite the slow start and change of plans.

So with our new target location set into the navigation system, it's off into the wild blue yonder.
The journey continues…