Chloe Zhang
Marine animals are increasingly consuming plastic, mistaking it for food. This is a pressing issue, as it affects hundreds of species, from zooplankton to whales. The reasons for this are twofold: plastic can look like food, and it can smell like food. Sea turtles, for example, often mistake plastic bags for jellyfish, while the smell of dimethyl sulfide (DMS)—a substance emitted by algae as it breaks down—can attract sea birds, drawing them into an 'olfactory trap'.
| Characteristics | Values |
|---|---|
| Number of animal species known to have consumed plastic | 200+ |
| Examples of animal species that consume plastic | Turtles, whales, seals, birds, fish, camels, sea cucumbers, plankton, shellfish, marine mammals, albatrosses, fulmars, shearwaters, and more |
| Reasons for consuming plastic | Resembles food in appearance, smell, feel, and sound; availability of plastic in feeding areas; mistaken identity of plastic for familiar food items |
| Health consequences | Serious health problems, starvation, death |
| Impact on offspring | Marine debris passed on to offspring during feeding |
Explore related products
![Gamma2 Vittles Vault Pet Food Storage Containers - Sealed Dog and Cat Food Storage Container, Fits up to 35lbs, Made in the USA - [12"L x 16.75"H]](https://m.media-amazon.com/images/I/71XEiKbubIL._AC_UL320_.jpg)
What You'll Learn
Plastic debris often smells like food to animals
Seabirds are especially at risk of consuming plastic. A study by scientists in Australia concluded that virtually all seabirds have consumed plastic. While scientists have long known that ocean plastic is consumed because it looks like food, a new study reveals that it is also because plastic debris often smells like food to animals.
As the oceans fill with plastic debris, hundreds of marine species eat astonishing amounts of it. The question of why so many species, from the tiniest zooplankton to whales, mistake so much of it for food has never been fully explored. Now, a new study explains why: It smells like food.
Algae are consumed by krill, a small crustacean that is the primary food source for many seabirds. As algae break down naturally in the ocean, they emit a stinky sulfur odor known as dimethyl sulfide (DMS). Seabirds in the hunt for krill have learned that the sulfur odor will lead them to their feeding grounds. It turns out that floating plastic debris provides the perfect platform for algae to thrive. As the algae break down, emitting the DMS odor, seabirds, following their noses in search of krill, are led into an "olfactory trap".
To investigate what attracts birds to plastic debris, scientists put beads made from the three most common types of plastic—high-density polyethylene, low-density polyethylene, and polypropylene—into the ocean at Monterey Bay and Bodega Bay off the California coast. The beads were sewn into mesh bags and tied to buoys to avoid any of them being eaten by wildlife. After three weeks, the beads were collected and the smell they gave off was analyzed. It didn't take long to identify DMS as a strong predictor of plastic consumption and the "keystone infochemical" that drew marine animals to plastic as if it was krill. Odor extraction tests confirmed that three common varieties of plastic acquired a "DMS signature" in less than a month.
The birds most attracted to the DMS odor are albatrosses, petrels, and shearwaters, which are the most severely affected by plastic consumption. Many of these birds nest in underground burrows, and juvenile birds spend many more months on the ground than birds that nest above the surface. Consequently, burrow-nesting birds rely much more heavily on their sense of smell to get around.
Plastic Surgery and BTS: Fact or Fiction?
You may want to see also
Explore related products
Marine animals mistake plastic for prey due to echolocation
Marine animals, including fish, turtles, whales, seals, and birds, are known to mistake plastic for prey. A study published in 2014 estimated that there are about a quarter of a billion metric tons of plastic in the ocean, with much of it in the form of small rice-sized particles.
Deep-diving toothed whales, such as sperm whales and beaked whales, are known to rely on echolocation, or biosonar, to locate and identify their prey. They emit clicks and create echoes that bounce off objects, and the strength of the returning echo helps them identify their prey. However, studies have shown that plastic debris in the ocean can confuse these whales, causing them to misinterpret their echolocation signals and mistake plastic for food.
Research has found that 100% of the plastics typically found in the stomachs of stranded whales, such as plastic bags, rope, and bottles, have similar or stronger acoustic target strengths compared to the echoes of their primary prey items, such as squid. This indicates that the whales are consuming plastic due to a "misperception of acoustic signals."
The accumulation of plastic in the oceans is a serious threat to marine life, leading to physical impacts such as perforation of tissues, infections, suffocation, and gastrointestinal tract blockage, which can result in starvation and death. Additionally, the chemicals carried by plastic waste can have unknown consequences for the health of marine animals.
While the exact number of animals that mistake plastic for food is challenging to determine, the problem is widespread and affects a diverse range of species.
Plastic Electrical Boxes and Bushings: When Are They Necessary?
You may want to see also
Explore related products
![Gamma2 Vittles Vault Pet Food Storage Containers - Sealed Dog and Cat Food Storage Container, Fits up to 50lbs, Made in the USA - [14"L x 20"H]](https://m.media-amazon.com/images/I/81IfhdDWS5L._AC_UL320_.jpg)
Plastic can get stuck in animals' digestive systems
Marine animals are consuming plastic in alarming amounts, and this is having devastating effects on their health. A sperm whale washed up at Wakatobi National Park in Indonesia in 2018 with 115 cups, 25 bags, four bottles, two slippers, and over a thousand pieces of plastic in its stomach. This is not an isolated incident, and such large amounts of plastic ingestion are proving fatal to many species.
In the United Arab Emirates, plastic ingestion causes half of all camel deaths. Camels eat garbage and lumps of plastic weighing between ten and sixty kilos. As the plastic cannot pass out of the stomach, it continues to grow until the animal dies of starvation.
Another example is the Laysan albatross, where chicks that ingested large amounts of plastic were found to have lower weights. The plastic prevents them from consuming enough food, affecting their growth and development.
Furthermore, plastic ingestion can also lead to the transfer of ingested debris to offspring. This was observed in adult Laysan albatrosses, which passed plastic debris to their chicks while feeding them. This not only affects the health of the chicks but also contributes to the spread of plastic pollution within the ecosystem.
The issue of plastic ingestion by animals is a pressing concern, and understanding the factors that lead to this behaviour is crucial for the preservation of many species.
Plastic Visors vs. Masks: Which Offers Better Protection?
You may want to see also
Explore related products
Plastic debris collects in areas where marine animals feed
The Great Pacific Garbage Patch is not an island of trash, but rather a gyre where debris is constantly moving with ocean currents and winds. It is located far out in the middle of the ocean, making it difficult to study and understand its impact on animals. However, we know that marine debris found in garbage patches can have detrimental effects on wildlife, including entanglement, ghost fishing, ingestion, and the transportation of non-native species.
One of the significant issues with plastic debris in the ocean is that it breaks down into smaller pieces, known as microplastics. These microplastics can be as tiny as rice-sized particles, making them easily ingestible by marine animals. Sea turtles, for example, often mistake clear plastic bags for jellyfish, one of their favorite foods. Other animals, such as fish, may consume microplastics because they resemble the small particles they typically eat.
In addition to resembling food visually, plastic debris can also smell like food to marine animals. A recent study found that as algae break down on floating plastic debris, they emit a sulfur odor known as dimethyl sulfide (DMS). This odor attracts seabirds that are hunting for krill, a small crustacean that feeds on algae. The birds follow the DMS scent, leading them into an "olfactory trap" where they mistake plastic for food.
The ingestion of plastic has severe consequences for marine animals. It can cause choking and intestinal injuries, and the false feeling of fullness can lead to starvation. The plastic debris also serves as a transport mechanism for chemical pollutants, potentially transferring toxic substances up the food chain to larger marine animals and even humans who consume seafood.
Plastic Discs: Easy Setup for A-130s
You may want to see also
Explore related products
Animals mistake plastic for familiar food items
Marine animals are consuming plastic in astonishing amounts. Over 200 animal species, including turtles, whales, seals, birds, and fish, have been documented consuming plastic. This is due to a variety of reasons, including the fact that plastic can resemble food items.
Sea turtles, for example, often mistake clear plastic bags for jellyfish. Similarly, fish eat plastic particles that resemble the small particles they normally eat. Plastic pellets, for instance, are thought to resemble tasty fish eggs. Young turtles prefer white plastic, while seabirds called shearwaters opt for red plastic.
In addition to visual similarities, plastic can also acquire the scent of food. As algae break down naturally in the ocean, they emit a sulfur odor known as dimethyl sulfide (DMS), which attracts seabirds searching for krill, a small crustacean that is their primary food source. Floating plastic debris provides a great surface for algae to grow on, and as the algae break down on the plastic, seabirds follow their noses into an "olfactory trap."
The amount and type of plastic ingested by animals often relate directly to their feeding behavior. Passive feeders may unintentionally eat microplastics with their food, while active feeders ingest plastic while searching for and capturing prey. Marine mammals, such as whales, are also highly susceptible to ingesting plastic, as they may mistake it for prey or inadvertently consume it through their prey.
Plastic License Plate Covers: Legal or Not?
You may want to see also
Frequently asked questions
More than 200 animal species are known to have consumed plastic, including turtles, whales, seals, birds, and fish.
Animals mistake plastic for food because it looks, smells, feels, and even sounds like food. For example, sea turtles often mistake clear plastic bags for jellyfish.
When animals eat plastic, it can get stuck in their digestive system and cause serious health problems. It can also lead to starvation, as in the case of camels in the United Arab Emirates, where plastic causes half of all camel deaths.
