As ocean enthusiasts we have all heard about plastic pollution and seen evidence while diving, walking the beach, or cruising along in a dive boat to and from a dive site. Plastic seems to be everywhere in seemingly every form: bags, toothbrushes, plastic bottles, even flip flops! It is heartbreaking to find yourself on a beautiful, remote beach only to see mounds of waste washed up from the incoming tide.
Plastic waste does not biodegrade; rather larger plastic pieces slowly break down into smaller pieces referred to as microplastics. Microplastics are extremely difficult to capture and have been found large quantities of protein sources for marine life, livestock, and humans. In fact, 88% of protein sources for human consumption contain some level of microplastic pollution. Even plants have shown evidence of microplastics as the soil and water used for growth contains these ubiquitous, harmful bits.
Ocean pollution is not the only source of microplastics, however. The clothes we wear and then wash breakdown as time progresses. Each time we wear a favorite pullover and then place it in the washing machine some portion of the garment frays away in the form of tiny microfibers.
These small fibers are essentially harmless if they are organic material like cotton or wool which biodegrade. When these fibers originate from synthetic textiles it is a different story. Millions of microfibers are shed during each spin cycle in a regular, residential washing machine. They are then released into the water treatment system and ultimately wind up in our rivers, lakes, and oceans. Most municipal water treatment systems do a good job of catching microfibers shed in the wash but they cannot capture all of them. This unintentional pollution is a serious problem that many people are unaware of.
We may use eco-friendly laundry products and wash our clothes in cold water to reduce our carbon footprint but we unknowingly release microscopic, harmful plastic fibers into our waterways. Nobody wants this to happen, of course, so what can we do about it? The answer might be right in front of you on your next scuba dive!
Manta rays and whale sharks are on every avid diver’s wish list. There is nothing quite like finding yourself in the path of one of these majestic giants of the sea! Ironically, some the largest creatures in the ocean feed on the smallest: plankton.
Manta rays in particular are extremely efficient at filtering out tiny plankton by using their gill rakers. As they open their mouths wide and swim directly into a cloud of plankton, the gill rakers grab onto the plankton as it moves over the rough surface. The water moves over the gill rakers leaving the plankton behind for a delicious and nutritious meal! Mantas are so efficient they manage to gobble up 19 million pieces of plankton every week. On average that is 12% of their body weight and these are not small animals!
This ingenious evolutionary development has been recognized by forward-thinking individuals who realize that nature often already has a solution. For example, Cleveland-based CLEANR utilizes the same concept as a manta ray’s gill rakers to funnel microfibers from washing machines into a filter that can be removed. Washing machines are the #1 contributor to microplastic pollution. This filtration system prevents those fibers from entering the wastewater and therefore reduces the burden on the water treatment plants.
There are also countries who understand that wide-spread change is needed in order to curtail this almost invisible pollution issue. For example, France passed a law in 2020 that will require washing machines sold there to have internal filters installed. This mandate will not go into effect until 2025 but there is at least positive movement towards adoption and implementation of pollution-reducing technology.
It can get very depressing to read about the negative impact improperly discarded plastic has on the environment. It can seem as though there is no hope for a solution. When we learn that solutions are being thought of it shines a bright light of hope. It is even more reassuring that it might actually work when those brilliant ideas are inspired by nature and creatures that have already tested the concept. Manta rays are spectacular animals and have evolved to survive on the tiniest of organisms. They are filter feeding specialists and are helping to pave the way to save our planet, one barrel roll at a time.