Technology that Combats Ocean Pollution



Ocean pollution takes many forms; from solids, to liquids, to gasses, and sometimes none of those things. Most people are aware of the worldwide problem of ocean plastics, including the “trash island” floating in the North Pacific Ocean, also called the Great Pacific Garbage Patch. However, lesser known issues include runoff, sunscreen chemicals, offshore drilling, and even noise pollution.

Scientists are still discovering the far-reaching impacts of ocean plastic pollution. It seems nearly everyday we see photos of sea turtles with plastic yokes from cans around their necks, or videos of people pulling plastic straws that are lodged up their noses. Beyond the direct impact to ocean life, plastic pollution poses a threat to humans as well. 

 

 Coordinador copy, CC BY-SA 4.0 

 

Plastics:

Plastics, as we have found out, are hard to break down. That is not to say that they don’t, just not well. Plastics that stay in the oceans long term are susceptible to breaking down into smaller sizes, called microplastics. These are often ingested by marine life, especially fish. Those microplastics are passed on to whatever eats that marine life, be that a human or another animal. 

Plastics also release chemicals into the water as they travel the oceans. These chemicals are typically not safe for consumption, and are slowly poisoning marine life, and through them, humans. These chemicals can be in the form of additives like flame retardants, UV stabilizers and colorants, to name a few.

 

 

 F.Alpizar, F.Carlsson, G.Lanz, B.Carney, R. C.Daniel, M.Jaime, T.Ho, Z.Nie, C.Salazar, B.Tibesigwa and S.Wahder, CC BY-SA 4.0 

Runoff Pollution:

Runoff pollution comes from the land, and can take many forms. A large percentage is from fertilizers and pesticides that make their way from lawns and fields to the waterways. This often happens during or after rainstorms, and can happen especially easily after a field has been freshly plowed. However it can happen all over - motor vehicles tend to drip oil onto the roads everyday, small amounts that add up over time and make their way to the sea. 

These chemicals can make it difficult for marine life, even outright killing aquatic environments. On top of that, fertilizers contain nitrogen to help plants flourish, and when those chemicals make it into larger water sources, they do just that. Typically when this happens we witness what is called an algal bloom.

 

 John Cassani, Public domain, via Wikimedia Commons

 

Algal blooms can be non-toxic, when they deal with algae types that don’t produce toxins, but we will focus on harmful algal blooms. Excess nitrogen, phosphorus, and other growth chemicals in fertilizers can influence algae to go wild, and when they do, algae can rise to the surface of the water in massive amounts. When this happens it can block light to the aquatic environment below the bloom, restricting plants that need light to grow.

Some algae produce toxins that kill fish, birds, and mammals. Even without the toxins, algae can block the gills of fish, or smother coral. The algae eventually dies when they’ve depleted the nutrient supply around them. Their process of decomposition eats up dissolved oxygen in the water, starving the other marine life that relies on it. More information on algal blooms can be found here.

 

 

 USEPA Environmental-Protection-Agency, Public domain, via Wikimedia Commons

Sunscreen chemicals: 

Summer rolls around, bringing fun in the sun and the ubiquitous urge to submerge in cold water. Combine those and we bring sunscreen into the mix - well, most of us do. Unfortunately, it has been discovered that the chemicals in sunscreen, though good at protecting our skin from harsh UV rays, are dangerous to marine life, especially coral. 

Scientists, like Ben Williams (who utilizes the HydroMoth in his projects to help restore and revitalize coral reefs, which we talk about in a different article), have to wear special sunscreen that does not contain oxybenzone and octinoxate, which scientists have determined are a cause of coral bleaching. Not only that, but The Smithsonian’s Ocean Science division tells us that, “Research shows octinoxate degrades into a chemical called benzophenone, which is a known cancer-causing agent and hormone disruptor.” 

Not only do these chemicals cause corals to bleach, but they also can hamper coral reproduction.

 

 

Photo Credit to Ben Williams 

 

Noise Pollution:

For most people, when we think about pollution we think about something physical, whether it be a solid or a liquid. However, noise itself has become a large ocean pollutant. Noise can come from a variety of sources, including offshore drilling, and ships (commercial tankers, naval ships, etc.).

So how does it pollute the ocean? Many aquatic species rely on sound for communication, breeding, feeding, and survival. Some of these species are well known, like whales, dolphins, and porpoises, but a lot of fish species use sound in their daily lives. There are even studies looking into how coral responds to sound - coral polyps are attracted to the sounds of a thriving coral reef, and will gravitate toward living reefs to land and colonize, something I talk about in this article about coral reef restoration.

Excessive noise, especially at the volume that offshore construction, offshore drilling, and naval exercises creates, can cause hearing loss in marine animals, can increase stress levels, can force animals to move from their preferred breeding grounds and migration paths, and can inhibit communication for feeding, breeding, and more.

 

 

 

Across the world we are working to fight ocean pollution before it reaches the oceans - by targeting the rivers that feed into the ocean. 

Great progress has been made setting up collectors in major rivers and harbors to collect trash before it enters the ocean. These can take a few different forms, from the popular Mr. Trash Wheel, created by Clearwater Mills and the Waterfront Partnership, who is a celebrity in Baltimore with his own Instagram account, to The Interceptor, made by The Ocean Cleanup. 

These large floating devices use booms to direct trash and other physical pollutants into a receptacle. There are lots of varieties, including the two from Osprey Initiative; the Litter Gitter and Litter Boom. Another innovative technology being used is The Bubble Barrier,which has been deployed in Amsterdam, Harlingen, Vila do Conde, Katwijk, and Wervershoof.

 

 

 Matthew Bellemare, CC BY-SA 2.0 

 

The next areas of focus include harbors, lakes, and canals. These are often heavily trafficked by humans, and history shows us that where humans go, trash follows. Progress has been made with trash skimmers, like the one created by Open Ocean Engineering, called Clearbot. Clearbot is an electrically-powered, autonomous trash collector that cleans up trash, oil, and invasive weeds.

RanMarine has also created the aquatic verson of the Roomba - the WasteShark. Its an autonomous aquadrone that collects trash, able to consume up to 200 liters of garbage in a single deployment. Pair that with zero greenhouse emissions and you’ve got a killer product. 

One company is attacking lake trash before it even gets to the water. The Keep Tahoe Blue organization has sent BEBOT to sift through the sandy shores of Lake Tahoe, retrieving small debris without harming the local flora and fauna. It is solar powered, and battery powered, and can cover 3,000 square meters in an hour.

 

Syced, CC0, via Wikimedia Commons

Ocean pollution:

For every way the ocean is being polluted, there are as many attempts to fix it. These are only some of the methods, with more being tested and implemented every day. 

• Biofences
• Sea bins
• Plastic-eating enzymes 
• Bubble curtains

 

Biofences: 

Biofences are a great way to reclaim plastic waste for a better cause. They act like booms, catching floating debris in rivers and waterways before it can enter the ocean. The plastic is shoved into nets, as seen in the picture below, before being sealed and deployed. 

Guatemala, one of the first users, has had success using biofences. The plastic that is caught and collected has helped residents in nearby communities to make additional income from recycling and even upcycling the plastic into other products. Other countries are quickly adopting the use of biofences, such as Honduras, the Dominican Republic,and Panama.

 

 Media Room Intendencia of Montevideo, CC BY-SA 4.0 

 

Sea bins:

Seabin is like the trash skimmers and garbage collectors mentioned above, but smaller. They look like little trash cans floating at water level, and are typically stationed in marinas and harbors. It's a relatively new technology, mainly implemented and tested in Sydney, Australia. 

 

Plastic-eating enzymes:

Researchers are delving deep to combat ocean plastic pollution by focusing on polyethylene terephthalate (PET), which is often found in consumer plastic goods - or to put it in perspective, makes up around 12% of global waste. 

However there is an enzyme called polyethylene terephthalate hydrolases (PETases) that breaks down the PET and turns it into something that other microorganisms can biodegrade. More research is being done on ways to synthesize PETase more effectively, but it could present a much needed solution to the massive problem of plastic pollution. More information can be found in this scientific report from Nature.com, and this article by the University of Texas, Austin. 

 

Bubble curtains:

Hero Lang (Fotograf)Fa. Hydrotechnik Lübeck (Rechteinhaber), CC BY-SA 3.0 DE 

 

To mitigate the impact of noise from things like offshore drilling, companies are installing bubble curtains to protect ocean life. 

The BBC explains how it works, saying that “Bubble curtains are based on a simple principle: sound travels faster through water than through air, because water and air have different densities. When sound waves hit the bubble curtain, they slow down, break up, and bounce against the bubbles, resulting in a loss of energy. The remaining sound that emerges on the other side of the curtain is therefore quieter.” 

Beyond noise pollution, these bubble curtains are also being used in conjunction with trash interceptors in rivers to drive floating debris into receptacles.

 

Hydrotechnik Lübeck GmbH, CC BY-SA 3.0 DE 

 

The issue of ocean pollution can seem as massive as the oceans themselves. It's true, the issues are large, and getting larger every year, but each and every one of us can try and make a difference. When you go out, whether you’re enjoying a river walk or sunbathing on the beach, be sure to collect your trash and dispose of it responsibly. When you’re taking care of your garden, and your lawn, please be mindful of the fertilizers and pesticides that you use, especially if you live close to a body of water. When you go swimming, snorkeling, or diving, please wear sunscreen that doesn’t hurt the coral reef. 

Sometimes it's the little things that add up. And sometimes it's all you need to do to help make a difference.