Ecosystems

Plastic Pollution and ecosystems

While that may be the most obvious answer it is by far not the only answer. There are many ways our human-produced polymers can enter ecosystems without us thinking about it. Microplastics have all the opportunities to do so. Directly affecting animals and wildlife is the entry of microplastics via the food chain. Scientist found out that mosquito larvae, small fishes and lugworms, as well as other small animals have consumed microplastics. Thereby, introducing these small, yet not less dangerous parts of plastic into the food chain. Almost all bacteria are not able to properly digest long synthetic polymers (plastics), therefore, the plastic accumulates in the body of the animal. When these small creatures are now being eaten by larger creatures, the plastic spreads in the food chain. Almost all carnivore animals can be affected by this. As an example, birds have been found to eat mosquitos contaminated with plastic.

Consequences on ecosystems

It is not hard to imagine that plastics do bring consequences onto the ecosystems in which they gather. Be that as it may, it is hard to imagine the sheer scale of impacts. Especially focused by the public and many scientists are marine ecosystems. Research shows that diverse marine systems are heavily disturbed by plastics.

 

Sea-surface and beaches

Clearly visible is the plastic accumulation at the sea-surface area. However, not every location has the same chances of being the spot for plastic to gather. If you get where I am going with this, then there will be one word in your mind “the great Pacific garbage patch”. If you already knew the infamous great pacific garbage patch, you will have known that it is a place, where a majority of the marine debris is gathering. But hold on – why is it gathering there?  In order to answer this question, we first need to be able to tell what a gyre is. A gyre is an enormous circular system of water current. There are 11 major gyres which in return create a system that circulates the water in our oceans. The biggest 5 of these gyres are collecting the most plastic and other marine debris. Once the plastic reaches the core of one of these 5 gyres, it is unlikely to ever leave the gyre again. Exposed to the sun, wind, waves and small animals brake the plastic down into smaller chunks (microplastics). So, even if these places are called garbage patches or plastic islands, in reality, they look more like a thick soup of small plastic bits. In places like this, where plastic has a significant dense concentration in the water, are lethal consequences for local animals (you can read more about it in (placeholder)). Now, I understand the currents are the places where all the plastic garbage gathers. Unfortunately, the gyres are not the only places where plastic debris is common. Even in a sea with almost no connection to the worldwide system of circulating water, like the Baltic Sea, there are massive plastic debris problems. So much so that every 100 meters between 50 to 300 litter items can be found on a Baltic sea beach.

Plastic in the deep sea

 

 It is hard to get a good overview of plastics in the deep sea. As a matter of fact, no one knows exactly, how many grams of plastic found their way into deep-sea ecosystems. That being said, scientist calculated that a big amount of plastic was missing in the survey of other ecosystems. A Royal Society paper takes a closer look at plastics in the deep sea and found significant evidence for an unknown microplastic sink. In the study, it is mentioned,

 

“Our results show for the first time, to the best of our knowledge, that substantial quantities of microplastic debris have accumulated in the deep sea.”

(RSOS paper)

 

 Further, the same study revealed that microplastic fibres are 4 times more abundant in the deep sea than in the sea surface area

Coral reefs and plastic

Coral reefs are in grave danger from anthropogenic influences. Climate change and plastic pollution harm them in many different ways.

More specifically, plastic affects the reproduction, growth, disease susceptibility and causes high fatality rates. The findings of several studies support that coral reefs with a higher concentration of plastics have an increased risk of disease development. The risk of disease could increase from 4% to 89% with the introduction of plastic, a study declares. Further, plastic trash suffocates the coral reefs. The photosynthesis of algae can be influenced and stopped by plastics; thereby, depriving considerable amounts of oxygen from the reef and suffocating it.