Alexander Gerst begibt sich für die Fernsehserie “Mission Erde” an Orte, bei denen mittels Forschung versucht wird, das fragile Ökosystem Erde besser zu verstehen. Auf seiner Expeditionsreise traf er auch die Wissenschaftlerin und Leiterin des...
The Ocan Cleanup Project by Boyan Slat seems like an ambitous and revolutionary approach to fight plastic pollution. If we take a second glance, however, its disadvantages and consequences might become more obvious. Even though there is an environmental impact assessment concerning the effect of this project on marine ecosystems and biodiversity, there is critisicm. Scientists, such as the biologist Rebecca Helm, state that important communities of organisms living near the water surface, the neuston, are left out in the assessment. Small animals such as blue buttons and by-the-wind sailors form patches which are crucial for the ecosystem. Why are those tiny organisms so incredibly important?
22.01.2019, The Atlantic, author: Rebecca Helm
Imagine you’re on a small boat in the middle of the open ocean, surrounded by what looks like a raft of plastic. Now flip the whole world upside down. You remain comfortably attached to your seat—the abyss towers above you, and all around, stretching up from the water’s surface, is an electric-blue meadow of life. What you thought was plastic is actually a living island. This meadow is made up of a diverse collection of animals. The most abundant are blue buttons and by-the-wind sailors, with bright-blue bodies that dot the sky like suns, and deep-purple snails found in patches so dense one scientist described collecting more than 1,000 in 20 minutes.
This is the neuston, a whole ecosystem living at the ocean’s surface. I once stumbled upon a raft of neuston when a storm blew it ashore in California. Many neustonic animals are vibrant highlighter colors, and the sand was saturated in bright blues and pale pinks. Together, these small creatures may function like upside-down coral reefs: an oasis of shelter and life far out to sea. As far back as the Cold War era, scientists were describing these colorful and important ecosystems, yet they still remain all but unknown. But now, as efforts to clean the ocean of plastic start up, our ignorance is putting this ecosystem at risk.
The neuston is home to more than blue buttons and bright snails. Erupting through the lawn of blue are crackling purple, red, gold, and yellow strands. These are Portuguese man o’ wars, whose tentacles stretch like lightning from the meadows of blue and pink. And among them, dragons roam.
Small nudibranchs, known as blue sea dragons, feast on blue buttons and man o’ wars, using their winglike cerata to grab and hold onto their tentacled prey. There are sea anemones, barnacles, copepods, color-changing crabs, specialized bacteria, even bugs, all living in this inverted reef in the middle of the open ocean. (Organisms that live exclusively by floating at the surface of the water are called pleuston, while neuston is a broader term, referring generally to the sea-surface ecosystem, which is why I chose to use it here.)
Just like reefs on the seafloor, this ecosystem does not stand apart from the open ocean around it. The neuston is a nursery for multiple species of larval fish and a hunting ground for paper nautilus octopuses. It supports sunfish, leatherback turtles, and diverse ocean grazers, which frequent these islands, relying on them as a food source. At night, soft-bodied jellies rise up to join the neuston, sparkling like fireflies. But all of this, from the blue sea dragons to the by-the-wind sailors, is in peril.
When I learned about the Ocean Cleanup project’s 600-meter-long barrier with a three-meter-deep net, a wall being placed in the open ocean, ostensibly to collect plastic passively as the currents push water through the net, I thought immediately of the neuston. How will it be impacted? But in the 146 pages of the Ocean Cleanup’s environmental-impact assessment, this ecosystem isn’t mentioned once.
As a response to the Biologists concern the founder of the Ocean Cleanup Boyan Slat states, that even though neuston organisms can be found within the area affected by the Ocean Cleanup, they are way more distributed and thus not that heavily affected as Helm claims. By comparing the distribution sizes of the neuston and the area of the garbage patch, according to Slat, not even close to 90% of the neuston will be destroyed and neuston organisms are able to recover from high losses since they have very high reproduction rates.