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Something small and bad

A new international study reveals the alarming dimensions of the danger of microplastics to the animals in the sea

A plastic bag at sea. Source: Ben Mierement, NOAA NOS (ret.
A plastic bag at sea. source: Ben Mierement, NOAA NOS (ret.

By Racheli Vox, Angle, Science and Environment News Agency

Last month it was placed in front of the Houses of Parliament in London A huge statue of a whale, made entirely of plastic bottles, disposable drinking straws and plastic bags. The statue is 10 meters long and weighs 250 kilograms, and these dimensions were not chosen randomly: according to some estimates, this is the amount of plastic that reaches the world's oceans every second. The sculpture, which last summer traveled throughout Britain, was placed as a protest against the harm to whales and other marine animals due to the plastic that pollutes their living environment.

The whales eat the plastic, thinking that it is animals that they feed on naturally (such as jellyfish), and this may cause them great suffering from blockage of the digestive system and even death from starvation. Now, new evidence shows that these large pieces of plastic aren't the only ones harming life in the sea. Even really tiny pieces of plastic, even microscopic, can harm the large marine animals.

Plastic instead of plankton

בReview Article Published last month in the journal Trends in Ecology & Evolution, an international team of researchers warns of the danger posed The microplastic, microscopic particles of plastic that move in sea currents, to large marine animals: species of whales, some species of sharks, as well as manta rays and finfish. All these marine animals belong to the group of plankton eaters: they filter tiny marine creatures, called plankton, from hundreds or even thousands of cubic meters of sea water per day.

"If there are also microplastic particles in the area, the animals have no way to avoid ingesting them and entering the plastic into their bodies," says Noam van der Haal, a doctoral student in the Department of Marine Civilizations at the University of Haifa, who studies the issue of microplastics under the guidance of Dr. Dror Ang 'To.

When the microplastic enters the body of large marine animals it causes devastating results. The plastic may block the absorption of nutrients in their bodies and damage their digestive system. In addition, it is possible that various toxins reach the body of the animals together with the microplastics. "There are persistent organic substances in the water, called Persistent organic pollutants," Van der Hal explains. "These are organic toxins that do not dissolve in water and when they are in a plastic environment there is a relatively high chance that they will be attached to it." That is, when an animal feeds on microplastics, it may introduce into its body a dose of toxins that may harm it as well.

Even if the plastic is not impregnated with these toxins, it does not lack other substances that may harm an animal that is exposed to it. "Many times there are materials in plastic that are intended, for example, to make the plastic flexible or to make it not burn, such as Bisphenol A And phthalates, which are problematic for health," says van der Hal.

These toxins accumulate in the body over the years, which may damage, for example, hormonal processes in those animals and even reduce the survival of that species.

Many species of whalessharks and bats are in danger today, due to factors such as hunting and entanglement in fishing nets. Almost half of the manta and fin whale species, two-thirds of the plankton-eating shark species and a quarter of the minke whale species are defined as endangered species. The impact of microplastics could make the situation even worse, bringing these animals even closer to extinction.

Not just big fish

Van der Hull emphasizes that the large marine animals are not the only ones that filter the water in search of plankton - so they are not the only ones that can be harmed by microplastics. "There are many more invertebrates (oysters, crabs, molluscs, etc., RO) that use this mechanism than sharks," he says.

And what is the situation in Israel? Although it is unlikely that we will soon see a blue whale on the shores of Israel, plankton eaters also live in our waters, which may be harmed by the microplastics in the Mediterranean Sea and the Gulf of Eilat, such as whale sharks and fin whales and, rarely, manta rays.

The origin of microplastics is in plastic products that have worn out and broken down, as well as in plastic parts that have been purposely produced in microscopic sizes for various uses, such as the plastic balls that are added to cosmetic products. The microplastics may also harm animals that do not eat plankton, and especially those who believe that the tiny plastic is food. Beyond the plankton eaters, many animals that are attached to the bottom or live near it, such as sponges, acetylenes, oysters, crabs and worms, are exposed to microplastics. The effects of microplastics are also evident in plankton, in many different types of fish, both carnivores and herbivores, and even in various seabirds such as The albatrosses who collect food from the water - and think that microplastic is also food. The microplastic and the toxins it absorbs may also pass through the food chain, harming animals that feed on the animals that ate it.

In various studies it was found that when the microplastic reaches the body of the various animals, it may cause, among other things, neurological problems, developmental problems, changes in the secretion of hormones and effects on growth and fetal development.

As mentioned, it was recently announced that microplastics were also found in bottled water, a fact that emphasizes the enormous dimensions of the phenomenon of microplastics in water in the world, although it is not yet known what the effect of microplastics is on humans.

The researchers suggest focusing long-term research and conservation efforts in several main areas: the Mediterranean Sea, the Gulf of Mexico, the Bay of Bengal in the Indian Ocean and the Coral Triangle (an area of ​​coral reefs in Southeast Asian waters). All these areas are home to large plankton eaters and the microplastic levels in the water are high.

Despite the knowledge that already exists on the subject, and considering that the production of plastic in the world is only increasing and the large marine animals continue to be at risk, the researchers emphasize that a lot of research is still needed in order to better understand the phenomenon of microplastics and how it harms the large marine animals.

Until we know more about the effects of microplastics, part of the solution to this problem is in our hands. The plastic reaches the sea as a result of excessive consumption of plastic products and the dumping of plastic waste in the coastal and marine environment and to reduce the use of plastic and prevent it from flowing into the sea, we do not have to wait for scientists.


More of the topic in Hayadan:

2 תגובות

  1. The interesting question is when a new type of marine animal will develop that will feed on plastic. Will it take 1000 years from a million years or do such creatures already exist and they will soon take over the oceans because they have endless food?

  2. An important paragraph is missing on the possibility that microplastics enter our food system in two ways,
    The simple and direct one when we eat fish,
    Also, desalinated water originating from the sea contains microplastics that pass through the membranes,
    The indirect second: purified sewage water that originates from desalinated water
    Used for irrigation, the microplastic penetrates vegetables and fruits
    and we eat

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