The world's oceans are under attack from man-made disasters

2024 Author: Seth Attwood | [email protected]. Last modified: 2023-12-16 15:55

The mass death of sea animals in the Avachinsky Bay in Kamchatka was due to toxic algae, according to experts of the Russian Academy of Sciences. But there are also signs of technical pollution - increased concentrations of oil products and heavy metals in water. After natural disasters, the ocean recovers itself. And what are technogenic fraught with?

For most of its history, humanity has been more consumerist about the ocean. Only in recent decades a new understanding has begun to form: the ocean is not just a resource, but also the heart of the entire planet. Its beating is felt everywhere and in everything. Currents affect the climate, bringing cold or heat with them. Water evaporates from the surface to form clouds. The blue-green algae that live in the ocean produce virtually all the oxygen on the planet.

Today we are more sensitive to reports of environmental disasters. The sight of oil spills, dead animals and garbage islands is shocking. Each time the image of the "dying ocean" is strengthened. But if we turn to facts, not pictures, how destructive are man-made accidents on big water?

Annushka has already spilled … oil

Of all oil and oil product pollution, the majority is associated with day-to-day leaks. Accidents account for a small part - only 6%, and their number is decreasing. In the 1970s, countries introduced stringent requirements for tanker ships and restrictions on shipping locations. The world tanker fleet is also gradually being renewed. The new vessels are equipped with a double hull to protect against holes, as well as satellite navigation to avoid shoals.

The situation with accidents on drilling platforms is more complicated. According to Peter Burgherr, an expert in assessing technological risks at the Paul Scherrer Institute, the risks will only increase: “This is connected, firstly, with the deepening of wells, and secondly, with the expansion of production in areas with extreme conditions - for example, in the Arctic . Restrictions on deep-sea drilling offshore have been adopted, for example, in the United States, but big business is struggling with them.

Why are spills dangerous? First of all, the mass death of life. On the high seas and oceans, oil can quickly take over vast areas. So, only 100-200 liters cover a square kilometer of water area. And during the disaster on the Deepwater Horizon drilling platform in the Gulf of Mexico, 180 thousand square meters were contaminated. km - an area comparable to the territory of Belarus (207 thousand).

Since oil is lighter than water, it remains on the surface as a continuous film. Imagine a plastic bag over your head. Despite the small thickness of the walls, they do not allow air to pass through, and a person can suffocate. The oil film works the same way. As a result, "dead zones" can form - oxygen-poor areas where life is nearly extinct.

The consequences of such disasters can be direct - for example, the contact of oil with the eyes of animals makes it difficult to navigate normally in the water - and delayed. Delayed ones include DNA damage, impaired protein production, hormone imbalances, damage to cells of the immune system, and inflammation. The result is stunted growth, decreased fitness and fertility, and increased mortality.

The amount of oil spilled is not always proportional to the damage it causes. Much depends on the conditions. Even a small spill, if it fell during the fish breeding season and happened in the spawning area, can do more harm than a large one - but outside the breeding season. In warm seas, the consequences of spills are eliminated faster than in cold ones, due to the speed of the processes.

Accident elimination begins with localization - for this, special restrictive booms are used. These are floating barriers, 50-100 cm high, made of special fabric that is resistant to toxic effects. Then comes the turn of water "vacuum cleaners" - skimmers. They create a vacuum that sucks the oil film along with the water. This is the safest method, but its main disadvantage is that collectors are only effective for small spills. Up to 80% of all oil remains in the water.

Since oil burns well, it seems logical to set it on fire. This method is considered the easiest. Usually the spot is set on fire from a helicopter or ship. Under favorable conditions (thick film, weak wind, high content of light fractions), it is possible to destroy up to 80–90% of all pollution.

But this should be done as quickly as possible - then the oil forms a mixture with water (emulsion) and burns poorly. In addition, combustion itself transfers pollution from water to air. According to Alexei Knizhnikov, head of the environmental responsibility program for WWF-Russia business, this option carries more risks.

The same applies to the use of dispersants - substances that bind oil products and then sink into the water column. This is a fairly popular method that is used regularly in the event of large-scale spills, when the task is to prevent oil from reaching the coast. However, dispersants are toxic by themselves. Scientists estimate that their mixture with oil becomes 52 times more toxic than oil alone.

There is no 100% effective and safe way to collect or destroy spilled oil. But the good news is that petroleum products are organic and are gradually decomposed by bacteria. And thanks to the processes of microevolution in the places of the spill, there are more precisely those organisms that are best at coping with this task. For example, after the Deepwater Horizon disaster, scientists discovered a sharp increase in the number of gamma-proteobacteria, which accelerate the decay of oil products.

Not the most peaceful atom

Another part of oceanic disasters is associated with radiation. With the onset of the "atomic age", the ocean has become a convenient testing ground. Since the mid-forties, more than 250 nuclear bombs have been detonated on the high seas. Most, by the way, are organized not by the two main rivals in the arms race, but by France - in French Polynesia. In second place is the United States with a site in the central Pacific Ocean.

After the final ban on testing in 1996, accidents at nuclear power plants and emissions from nuclear waste processing plants became the main sources of radiation entering the ocean. For example, after the Chernobyl accident, the Baltic Sea was in first place in the world for the concentration of cesium-137 and in third place for the concentration of strontium-90.

Although precipitation fell over land, a significant part of it fell into the seas with rains and river water. In 2011, during the accident at the Fukushima-1 nuclear power plant, a significant amount of cesium-137 and strontium-90 were ejected from the destroyed reactor. By the end of 2014, the isotopes of cesium-137 had spread throughout the Northwest Pacific.

Most of the radioactive elements are metals (including cesium, strontium, and plutonium). They do not dissolve in water, but remain in it until the half-life occurs. It is different for different isotopes: for example, for iodine-131 it is only eight days, for strontium-90 and cesium-137 - three decades, and for plutonium-239 - more than 24 thousand years.

The most dangerous isotopes of cesium, plutonium, strontium and iodine. They accumulate in the tissues of living organisms, creating a danger of radiation sickness and oncology. For example, cesium-137 is responsible for most of the radiation received by humans during trials and accidents.

This all sounds very disturbing. But now there is a tendency in the scientific world to revise early fears about radiation hazards. For example, according to researchers at Columbia University, in 2019, the plutonium content in some parts of the Marshall Islands was 1,000 times higher than that in samples near the Chernobyl nuclear power plant.

But despite this high concentration, there is no evidence of significant health effects that would prevent us from, say, eating Pacific seafood. In general, the influence of technogenic radionuclides on nature is insignificant.

More than nine years have passed since the accident at Fukushima-1. Today, the main question that worries specialists is what to do with radioactive water, which was used to cool fuel in destroyed power units. By 2017, most of the water had been sealed off in huge cisterns onshore. At the same time, groundwater that comes into contact with the contaminated zone is also contaminated. It is collected using pumps and drainage wells and then purified using carbon-based absorbent substances.

But one element still does not lend itself to such cleaning - it is tritium, and around it most of the copies break today. The reserves of space for storing water on the territory of the nuclear power plant will be depleted by the summer of 2022. Experts are considering several options for what to do with this water: evaporate into the atmosphere, bury or dump into the ocean. The latter option is today recognized as the most justified - both technologically and in terms of consequences for nature.

On the one hand, the effect of tritium on the body is still poorly understood. What concentration is considered safe, no one knows for sure. For example, in Australia the standards for its content in drinking water are 740 Bq / l, and in the USA - 76 Bq / l. On the other hand, tritium poses a threat to human health only in very large doses. Its half-life from the body is from 7 to 14 days. It is almost impossible to get a significant dose during this time.

Another problem, which some experts consider a ticking time bomb, are barrels of nuclear fuel waste buried mainly in the North Atlantic, most of which are located north of Russia or off the coast of Western Europe. Time and sea water "eat up" the metal, and in the future, pollution may increase, says Vladimir Reshetov, associate professor of the Moscow Engineering Physics Institute. In addition, water from spent fuel storage pools and waste from nuclear fuel reprocessing can be discharged into wastewater, and from there into the ocean.

Time bomb

Chemical industries pose a great threat to communities of aquatic life. Metals such as mercury, lead and cadmium are especially dangerous for them. Due to strong ocean currents, they can be carried over long distances and not sink to the bottom for a long time. And off the coast, where the factories are located, the infection primarily affects benthic organisms. They become food for small fish, and those for larger ones. It is the large predatory fish (tuna or halibut) that get to our table that are most infected.

In 1956, doctors in the Japanese city of Minamata encountered a strange illness in a girl named Kumiko Matsunaga. She began to haunt sudden seizures, difficulties with movement and speech. A couple of days later, her sister was admitted to the hospital with the same symptoms. Then polls revealed several more similar cases. Animals in the city also behaved in a similar manner. Crows fell from the sky, and algae began to disappear near the shore.

Authorities formed the "Strange Disease Committee", which discovered a trait common to all infected: the consumption of local seafood. The plant of the Chisso company, which specialized in the production of fertilizers, fell under suspicion. But the reason was not immediately established.

Only two years later, the British neurologist Douglas McElpine, who worked a lot with mercury poisoning, found out that the cause was mercury compounds that were dumped into the water of Minamata Bay more than 30 years since the start of production.

Bottom microorganisms converted mercury sulfate into organic methylmercury, which ended up in fish meat and oysters along the food chain. Methylmercury readily penetrated cell membranes, causing oxidative stress and disrupting neuronal function. The result was irreversible damage. The fish themselves are better protected from the effects of mercury than mammals due to the higher content of antioxidants in the tissues.

By 1977, authorities counted 2,800 victims of Minamata Disease, including cases of congenital fetal abnormalities. The main consequence of this tragedy was the signing of the Minamata Convention on Mercury, which banned the production, export and import of several different types of mercury-containing products, including lamps, thermometers and pressure measuring instruments.

However, this is not enough. Large quantities of mercury are emitted from coal-fired power plants, industrial boilers and home stoves. Scientists estimate that the concentration of heavy metals in the ocean has tripled since the start of the industrial revolution. To become relatively harmless to most animals, metallic impurities must travel deeper. However, it could take decades, scientists warn.

Now the main way to deal with such pollution is high-quality cleaning systems at enterprises. Mercury emissions from coal-fired power plants can be reduced by using chemical filters. In developed countries this is becoming the norm, but many third world countries cannot afford them. Another source of metal is sewage. But here, too, everything depends on money for cleaning systems, which many developing countries do not have.

Whose responsibility?

The state of the ocean is much better today than it was 50 years ago. Then, at the initiative of the UN, many important international agreements were signed that regulate the use of the resources of the World Ocean, oil production and toxic industries. Perhaps the most famous in this row is the UN Convention on the Law of the Sea, signed in 1982 by most countries in the world.

There are also conventions on certain issues: on the prevention of marine pollution by dumping of wastes and other materials (1972), on the establishment of an international fund for compensation for damage from oil pollution (1971 and 1974), and harmful substances (1996) and others.

Individual countries also have their own restrictions. For example, France has passed a law strictly regulating the discharge of water for factories and plants. The French coastline is patrolled by helicopters to control tanker discharges. In Sweden, tanker containers are labeled with special isotopes, so scientists analyzing oil spills can always determine which ship was discharged from. In the United States, a moratorium on deep sea drilling was recently extended to 2022.

On the other hand, decisions made at the macro level are not always respected by specific countries. There is always an opportunity to save money on protective and filtering systems. For example, the recent accident at the CHPP-3 in Norilsk with the discharge of fuel to the river, according to one of the versions, occurred for this reason.

The company did not have equipment to detect subsidence, which led to a crack in the fuel tank. And in 2011, the White House Commission to investigate the causes of the accident on the Deepwater Horizon platform concluded that the tragedy was caused by the policy of BP and its partners to reduce security costs.

According to Konstantin Zgurovsky, Senior Advisor of the WWF-Russia Sustainable Marine Fisheries Program, a strategic environmental assessment system is needed to prevent disasters. Such a measure is provided for by the Convention on Environmental Impact Assessment in a Transboundary Context, which has been signed by many states, including the countries of the former USSR - but not Russia.

"The signing and use of SEA allows to assess the long-term consequences of a project in advance, before the start of work, which makes it possible not only to reduce the risk of environmental disasters, but also to avoid unnecessary costs for projects that can be potentially dangerous to nature and humans."

Another problem that Anna Makarova, Associate Professor of the UNESCO Chair “Green Chemistry for Sustainable Development,” draws attention to is the lack of monitoring of waste burials and mothballed industries. “In the 90s, many went bankrupt and quit production. Already 20-30 years have passed, and these systems began to simply collapse.

Abandoned production facilities, abandoned warehouses. There is no owner. Who is watching this? " According to the expert, disaster prevention is largely a matter of managerial decisions: “The response time is critical. We need a clear protocol of measures: which services interact, where the funding comes from, where and by whom the samples are analyzed."

The scientific challenges are related to climate change. When ice melts in one place and storms break out in another, the ocean can behave unpredictably. For example, one of the versions of the mass death of animals in Kamchatka is an outbreak of the number of toxic microalgae, which is associated with climate warming. All this is to be studied and modeled.

So far, there are enough ocean resources to heal their "wounds" on their own. But one day he may present an invoice to us.