An OceanGybe Dispatch

Our immediate initial impression was that the image of the gyre as a floating island of plastic is completely false, and is a media generated fantasy rather than a scientific fact. There was nowhere where the entire surface of the ocean was covered with plastic. It would be better described as a gigantic plastic soup or plastic potpourri.

 

 

Vancouver, 31 October 2010 

An OceanGybe Dispatch: Lessons leant from our trip through North Pacific Gyre on a small sailboat

 

An OceanGybe Dispatch: Lessons leant from our trip through North Pacific Gyre on a small sailboat

© OceanGybe

 

By Bryson Robertson, The OceanGybe Expedition  

The OceanGybe crew and Khulula departed Maui, Hawaii on the 24th of July on route to the North Pacific Gyre and then onwards to Vancouver, British Columbia, Canada. We had been looking forward to our trip through the gyre since we first heard about it in 2000, and we anxious to see the “floating island” of trash in the middle of the Pacific. The route to get into the gyre from Maui is relatively simple: Sail north into the beginning of the High (approximately 30′N), then motor East to 35′N and 145′W - where Charles Moore of the Algalita Marine Research Foundation had suggested the highest density of plastic may be located. From there we planned to spend a few days doing manta trawls and visual studies before taking a 90′ turn and heading due north into the westerly winds in the 45′N vicinity. This was our plan at least…

Unfortunately, the North Pacific High is far from a stationary weather system. It is always present in some form and is generally located between 30′N - 50′N and between 135′W and 165′W - which may not seem that much. Well, those co-ordinates sketch out an area approximately 2000km X 3000km. In Khulula, given perfect sailing conditions, it would take us approximately 10 - 15 days to cross this area just once. So when the North Pacific High decided to move 2000km in three days while we were sailing north, we are powerless to change our course dodge it and will be left powerless (aka wind-less).

 

An OceanGybe Dispatch: Lessons leant from our trip through North Pacific Gyre on a small sailboat

© OceanGybe

 

When planning our trip to the ‘Center of the Gyre’, we thought we may get lucky and be able to cross it with just 900km of diesel fuel. In order for us to carry this amount of fuel, we purchased spare jerry cans from all over Maui and had strapped them to all the outside rails of the boat - it seemed rather odd to be purchasing all this petroleum to go looking for a petroleum product ! Unfortunately, the reality of the situation rapidly set-in once we looked at the weather charts after having left Maui and were 400 km from land. It was not going possible for us to venture as far as the ‘centre’ of the High due to our limited diesel range. So we decided to follow the western and northern edges of the High/Gyre for 5 days of slow motoring and manta trawling.  We were not sure if this portion of the gyre had been sampled before and thought it would provide good reference data for the Algalita team. 

 

An OceanGybe Dispatch: Lessons leant from our trip through North Pacific Gyre on a small sailboat

© OceanGybe

 

The manta trawl features a rectangular opening measuring 0.45m X 0.30m, and a decreasing cone of 500 μm mesh, which ends in a collection bottle. The collection bottle accumulates everything bigger than 500μm that has been collected during the trawl. According to the NOAA Manta Trawl procedure, we were directed to complete 15 min trawls while travelling at 4 knots (approx. 7km/hr) and maintain the trawl net at 50% of its depth. So in essence we were trawling the top 15cm of a 45cm wide swath of the North Pacific. An infinitesimally small amount when contrasted to the size of the North Pacific. 

 

An OceanGybe Dispatch: Lessons leant from our trip through North Pacific Gyre on a small sailboat

© OceanGybe

 

Completing a manta trawl from a small sailboat is not impossible, but requires a little extra work. We rigged our spinnaker pole to the mast, attached a block (pulley) through the end of the spinnaker pole and ran a line from a winch to the trawl net. We were able to raise and lower the trawl net, via use of the manual winch. This entire system was then held in place by two other static lines to deal with the stresses and ensure the net was kept out of the area of disturbed water created by the boat. While trawling, we recorded both final and initial latitude and longitude, boat speed, wind speed, sea conditions, water temperature, and atmospheric pressure. All this data is invaluable to correlating the amount of plastic collected to the conditions of the North Pacific High Pressure. 

Our immediate initial impression was that the image of the gyre as a floating island of plastic is completely false, and is a media generated fantasy rather than a scientific fact. There was nowhere where the entire surface of the ocean was covered with plastic. It would be better described as a gigantic plastic soup or plastic potpourri. Sitting on the boat pulpit doing 30 min visual counts, one sees uncountable thousands of tiny pieces of plastic floating past the hull of the boat. They are literally uncountable in any sense, they are too numerous. We counted only items bigger than 10mm, and still resulted in counts well over 500 in the 30 min span. As you start to gaze around towards the horizon, it is very likely that a fishing float, milk crate, plastic bottle, net or other forms of flotsam will impede you view towards the horizon. It seemed that for every bit of minute marine life, there are numerous more pieces of small plastic floating in the water. Shocking when you consider how extremely small our path through the North Pacific was… 

 

An OceanGybe Dispatch: Lessons leant from our trip through North Pacific Gyre on a small sailboat

© OceanGybe

 

Every time we winched the net back on board Khulula, there was plastic in the collection jar - after just 15 minutes of towing. We are amazed to find significant amounts of plastic in every trawl we completed along our route to and from Hawaii, regardless of whether it was in the “Gyre” or not. This could indicate that a much larger portion of the ocean is filled with these tiny pieces than we previously thought. Almost every trawl collected had higher proportions of plastic than natural marine life - the sample analysis is currently on-going and complete results will be forthcoming. 

 

An OceanGybe Dispatch: Lessons leant from our trip through North Pacific Gyre on a small sailboat

© OceanGybe

 

Interestingly enough, we saw far fewer pop/beverage bottles than assumed. The majority of the large pieces we saw were fishing floats, crates, styrofoam blocks, fishing nets and plastic bags. Every time we pulled one of these pieces from the ocean, we left a small ecosystem of small pelagic fish swimming around looking for shelter. Crabs, goose-neck barnacles, and small pieces of tropical coral were found on many of the plastic pieces studied, thus giving credence to the fears of invasive species movement around the globe via plastic debris. 

While the ‘plastic island’ may not truly exist out in the middle of the Pacific, there is no doubt that we are only just beginning to see the extent of the damage caused by these tiny pieces of plastic. Check back to www.oceangybe.com to see full results.

 

An OceanGybe Dispatch: Lessons leant from our trip through North Pacific Gyre on a small sailboat

© OceanGybe

 

 

Related information

Calling all Garbage Patch Enthusiasts: NOAA Samples Plastics in North Pacific!

De-mystifying the “Great Pacific Garbage Patch”

The Pacific Garbage Patch: Myths & Realities



One Response to “ An OceanGybe Dispatch ”

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