The tears of the oceans

1. The hydrocarbon pollution over the seas

Many pepole heard of the oil spills, from oil rig or ship shipwreck. But does anybody heard of the iron wreck that lies at the sea's bottom, and are still filled with oil or any hydrocarbon-based fuel for ship?

The title can be translated to "wreck and pollution : the black tears of the ocean". This is the title of a documentary, last less than 1 hour. It draw up a dreadful board : our oceans are constantly threatened by a massive time-bomb that can release huge volumes of hydrocarbon. Following the biologist Dagmar Schmidt Etkin, there are 6338 wreck lying at the bottom of the oceans.

It includes only the ships that weigth more than 150 barrel for the oil tankers and 400 barrel otherwise.

Almost all theses wrecks lies along the commercial shipping ways, or along the coasts. Most of them were sunked during World War II. Taking in account the size and type of ship, supposing the fuel tank are still filled at 10 to 90% of their volume, the ship wrecks contains together 2 (tanker filled up to 10%) to 20 (tanker filled up to 90%) million tons of hydrocarbon.

Moreover, theses ship wrecks also implies other problems, such as the toxicity of the iron. The main danger of theses ship wrecks is their fuel tanker. Indeed, it is known that after a certain time passed under the sea, a piece of iron is eaten by bacteria and other micro organism.

Due to this fact, the ship wrecks became real time bombs.

An another fact, more concerning : due to oil shortage at during WWII, the nazi decided to mix the coal with oil to make the fuel needed for ships. This mix is much more toxic and dangerous for the oceans than the "regular" ship's fuel.

An other risk is the ship wreck rush, in order to find any treasure still in the ship wrecks. Unfortunately, this weakened the tanker's partition, making it harder to pump. In all this story, hte norvegian government is the only one that decided to extract all the hydrocarbon from ship wrecks. The worst is that the technology required for theses operations exists, but nobody want to put money for that.

Moreover, there is a juridic void. The state of the ship sunked doesn't have to pump the hydrocarbon it the ship were sunked during the war. In other cases, it is legal for states to let the wrecks as they are. While many governments refuses to act, the bacteria weaken more and more the ship wrecks.

An another thing are the oil spills. More widely known, they occure because of accidents and catastrophee, that could have been avoided in most of the cases. Let's see some examples :

The 20th april 2020, an explosion on the offshore oil rig deepwater horizon occurs, under the control of the english company British Petroleum or BP. Thisexplosion instantly kills 11 people, and causes a massive ecological disaster, releasing a massive 780 000 meters cube of oil in the mexican gulf, following estimation.

First, the oil leak from the rig as estimated at 159 000L per day, an estimation soon replaced by the 795 000 L per day of the national oceanic and administration, an institution in the USA.

After several days, the 29th april, the oil spill was estimated to be 3000 km²-wide. Its size rose quickly, to reach 9900 km² the 30th april. After three months, the volume of the spill is estimated to be between 300 and 630 million L of oil.

Following BP, only 26% of this oil would be still in the nature in the early 2011. This estimation is supposed to be the half of the truth by the scientific community, estimating that this proportion would be around 50% or more.

The underwater wells isn't just a hole. to prevnet gas or oil to spill out of the well, a special mud is injected in the drilled hole after drilling to maintain a sufficent preasure in the well, and after it is cemented. In the case of deepwater horizon, the well was cemented.

To be sure that the cement use will fill the wall of the well, centralisers are used to stuck the fluid on the walls oif the well. In the case of BP, only 6 centralisers were used instead of the 21 recommended by the local operator, halliburton.

Moreover, BP also dismissed the team of Schlumberger supposed to check that the well was well-cemented. The cost-saving was estimated to 118 000 $ (BBC news).

Also, BP decided to use a single line of cement around the well, cheap but not enough to prevent gas or oil from blowing-up, instead of choosing to add a "liner", an another section that is more secured, but also more expensive.

Finally, a piece of the rig could have prevented all this disaster. It is called the BOP (Blowout Preventer). It iis a piece formed of multiples high-preassure valves, designed to prevent any blowout. But this piece must be conserved in precise condition (cold temperature, around 20 degrees, not more). BP didn't respect that clause (to save money), making the BOP quite obsolete.

All theses errors lead to the disaster we know.

The conceit of compliance flag is that it is a sort of equivalent in the marine language to the fiscal paradise, near of declaring its revenue in an country where the taxes are less important. The constraints on the security and safety controls. This conceit can leads to humanitarian and ecological disaster.

The Erika was an oil tanker built in 1975 in Japan, and was populart for it company because of its inexpensivness with 10% less steel than other similiar tankers. It sunked the 12th december 1999 in the bay of Biscay, releasing tons of hydrocarbon, causing a massive disaster.

The Erika sailed out of Dunkerque the 8th december with 31 000 tons of heavy-fuel oil on board, and entered in the bay of Biscay while a storm ocured, and broke in two before sinking.

The Erika was under the maltese flag, a compliance flag, reducing the cost of registering. Also, expert pointed out that the Erika, due to it age (nearly 25 years) and use (oil-tanker) should have been more controlled. Moreover, there is a lack in the maintenance of the ship and in it own construction.

Finally, the society that owned the Erika and the society that provided thecertificates of good condition were sentenced to pay idemnities of 192 million €, plus individual penalitie.

The Amoco Cadiz is classified as a VLCC (Very Large Crude Carrier). It is owned by a company that subcontract the transport of crude oil for Shell, and is under the liberian flag, an compliance flag.

The ship passed near the western tip of Brittany, then headed the United Kingdom. In the mearly morning it was north of Ushant and 30 km west of Portsall when it had to turn to avoid another ship and jammed her rudder, full over to port. The engine was shut down to make repairs, but they were not successful.

The ship was then driven oward the coast by the wind. After that, a small boat attached a hawser and tried to slow the vessel's drift for two hours, unsuccessfully though. The supertanker captain's decided to drop an anchor, but the cable that join the anchor to the ship broke. Then, a cable was successfully attached 10 hours after the ship began to drift. Unhopefully, it didn't help and the ship hit a rock nearthe coast a first time, but continued to drift. It then hit a second roch, that opened a hole in the engine room, and the wawes finished to broke the ship in two.

Finally, it is again a question of money that lead to an oil spill. The company was sentenced to pay penalities of 223 million $ to the USA.

Today, it is known that there is plastic in the oceans. There is even a 6th continent made of plastic, and we maybe all heard of some turtle that mistaken plastic bags for food, and died after having eaten plastic.

But for the for the majority it isn't plastic as we can imagine, like bags, toys or cloths, it is about microplastic, mostly.

As we can see, the microplastic originates from several sources. The main problem with that it is that microplatic is eaten by little fishes and then went higher in the food chain. Also, all the chemical aditives in the platstic to improve it properties is leached and pass in the water.

Finally, the microplastic went higher in the food chain to us. Everybody doesn't eat the same quantity in average, of course.

Due to human activities, the quantity of CO2 released in the atmosphere increase. But does it impact the oceans?

It is estimated that the oeans aborbed around 25% of the CO2 emited each years ( 1 ). For the atmosphere and for us, it could be a good new, because it limits its warming. But for the oceans, ti's not the case.

Every soda maker know that, putting CO2 in a bottle full of water, and you'll get a fizzy water. Don't panic, the ocean won't turn into a massive soda ! But the more concerning consequence is the reduction of oceans pH (a low pH is equivalent to an acid susbtance). The ocean will be more acid, and the more threatened organism are the living being with a shell (oyster, mussel,and other molluscs).

During the freezig time, the pH of the oceans increased by 0,2 and lowered by 0,2 in the warming period. Since the industrail evolution, where the pH was estimated at 8,1, it is esimated that the pH has lowered by 0,1. It can seam to be nothing, but the pH is a logarithmic value, and it means an increase of acidity by 28%. The forecast to 2100 are an increase of acidity by 150%, and means a pH around 7,8.

This threats doesn't affect all the oceans in the same way : as for the warming, the artic and antartic oceans are the more affected.