Sea Birds' Stomachs: A Plastic Pollution Story

Plastic pollution in the ocean is a pressing issue, with an estimated 4.8 to 12.7 million metric tons of plastic dumped into the ocean each year. This plastic pollution has severe consequences for marine life, including seabirds, who often mistake plastic for prey or food. The problem has grown exponentially, with recent studies finding plastic in the stomachs of 90% of seabirds. This plastic ingestion has led to the coining of a new term, plasticosis, to describe the stomach damage and health issues caused by ingesting plastic. The presence of plastic in seabirds' stomachs can cause kidney damage, higher concentrations of uric acid, and negatively impact cholesterol and enzymes. It also reduces the volume of the stomach, leading to malnutrition and starvation. With the rate of plastic manufacturing increasing, the threat to seabirds and other marine life is only expected to grow, highlighting the urgent need for systemic change to address plastic pollution.

Plastic ingestion by seabirds has increased from 5% in 1960 to 80% in 1980

Seabirds are birds that live primarily over the open ocean, far away from humans. They have unique adaptations, such as specialised feathers and a desalination system that allows them to drink seawater safely by converting it into freshwater. However, the growing presence of plastic in the oceans poses a significant threat to these birds.

In the 1960s, less than 5% of seabirds were found with plastic in their stomachs. However, by 1980, this number had surged to 80%. This drastic increase is attributed to the rising global production and use of plastic, with plastic pollution saturating the oceans. The link between plastic manufacturing and seabird ingestion of plastic is evident, as the ingestion rate mirrors the increase in plastic production, which doubles every 11 years.

The impact of plastic ingestion on seabirds is profound and far-reaching. It affects the birds' health, growth, and survival rates. Ingested plastic can cause kidney damage, leading to higher concentrations of uric acid and negatively affecting cholesterol and enzyme levels. Additionally, plastic reduces stomach volume, often resulting in starvation. The presence of plastic in the stomach can also lead to a lower likelihood of seabirds surviving to adulthood, as it can hinder their growth and development.

The problem of plastic ingestion is not limited to adult seabirds; it also extends to their chicks. Adult birds may inadvertently collect plastic debris, mistaking it for prey, and bring it back to their nests to feed their young. Unfortunately, chicks are unable to regurgitate the plastic pieces, leading to fatal consequences. This issue is particularly prominent in albatross colonies, where approximately one-third of the chicks perish annually due to plastic ingestion.

The plastic found inside seabirds varies in size and type, including bags, bottle caps, synthetic fibres from clothing, and tiny rice-sized bits that have broken down over time. The ingestion of plastic by seabirds is not only detrimental to their health but also serves as a stark reminder of the pervasive nature of plastic pollution in our oceans.

Plastic ingestion is projected to affect 99% of seabird species by 2050

Seabirds are birds that primarily live in the ocean, far away from humans. They have unique adaptations such as specialised feathers and a desalination system that allows them to drink seawater safely. Unfortunately, the ocean is a source of plastic pollution, which poses a serious threat to these birds. Humans dump an estimated 4.8 to 12.7 million metric tons of plastic into the ocean each year, and this plastic is often ingested by seabirds, causing harmful and even fatal effects.

The problem of plastic ingestion by seabirds has grown exponentially over the years. In the 1960s, less than 5% of birds were found with plastic in their stomachs, but by the 1980s, this number had risen to over 80%. According to a study published in 2015, if current trends continue, plastic ingestion is projected to affect 99% of seabird species by 2050. This means that almost all seabirds will have eaten plastic, including bags, bottle caps, and plastic fibres from synthetic clothes.

The Southern Ocean boundary in the Tasman Sea between Australia and New Zealand is predicted to be one of the areas with the highest impact. This is due to the large number of seabird species in the region that are prone to plastic ingestion, even though plastic concentrations are lower than in other sites. The ingestion of plastic can lead to gut impaction, weight loss, and even death in seabirds. It can also affect their kidney function, leading to higher concentrations of uric acid and negatively impacting their cholesterol and enzymes.

Additionally, plastic ingestion can have indirect effects on seabird populations. Adult birds may mistake plastic debris for prey and feed it to their chicks, who are unable to regurgitate the plastic pieces and often die as a result. This reduces the survival rate of juveniles, impacting the overall population of seabirds. Furthermore, plastic ingestion can also lead to a false sense of fullness, causing the bird to stop eating and slowly starve to death.

While the problem of plastic ingestion by seabirds is severe, there is still an opportunity to mitigate its impact. Effective waste management and reducing the use of plastic, especially single-use plastics, can help reduce the threat to these vulnerable creatures.

Plastic ingestion causes internal wounds, digestive blockages, starvation, and death

Seabirds are among the most vulnerable animals to plastic pollution. An estimated one million seabirds die each year from ingesting plastic, with the problem growing exponentially. In the 1960s, less than 5% of birds had plastic in their stomachs, but by the 1980s, this number had soared to over 80%. It is predicted that by 2050, 99% of seabird species will be consuming plastic.

The presence of plastic in seabirds' stomachs also impacts kidney function, increasing uric acid concentrations and negatively affecting cholesterol and enzyme levels. The chicks of seabirds are particularly vulnerable to plastic ingestion. Adult birds may mistake plastic debris for prey, feeding it to their chicks, who are then unable to regurgitate it and often die as a result.

Plastic pollution in the oceans is a significant contributor to the high mortality rate among seabirds. As plastic breaks down in the ocean, it releases toxic chemicals, which are then ingested by algae, shellfish, and other sea creatures that seabirds feed on. These toxins work their way up the food chain, accumulating in the stomachs of seabirds and leading to severe health issues and death.

The impact of plastic ingestion on seabird populations is severe, with nearly half of all seabird species in decline and 28% already endangered. As plastic pollution continues to infiltrate even the most remote areas of our planet, the survival of seabirds and other marine life is increasingly threatened.

Plastic found in seabirds includes bags, bottle caps, synthetic fibres, and tiny plastic bits

Plastic ingestion is a serious issue for seabirds, with an estimated one million birds dying as a result every year. In the 1960s, less than 5% of seabirds had plastic in their stomachs, but by 1980, this figure had jumped to 80%. It is projected that by 2050, 99% of seabird species will have ingested plastic.

In addition to larger pieces of plastic, seabirds also ingest tiny plastic bits that have been broken down by the sun and waves. These microplastics can cause significant harm as they churn in a bird's stomach. Flesh-footed shearwaters, a species of seabird, have been found to have high rates of plastic ingestion, with plastic pieces stamped with the word "plastic" found in their stomachs. Even millimeter-thick microplastics can lead to severe stomach damage, known as "plasticosis".

The presence of plastic in seabirds' stomachs can impact their kidney function, leading to higher concentrations of uric acid and negatively affecting cholesterol and enzyme levels. It also reduces the volume of the stomach, often resulting in malnutrition and starvation. Plastic debris can accumulate in the digestive tract, giving a false sense of fullness and causing the bird to stop eating and slowly starve.

Seabirds may associate the scent of some plastics with food due to the presence of DMS

Seabirds are increasingly ingesting plastic, causing severe health issues and even death. The problem has grown exponentially, with projections indicating that by 2050, 99% of seabird species will be consuming plastic.

New research has revealed that certain seabirds associate the scent of some plastics with food, which is detrimental to their health. This phenomenon is linked to the presence of dimethyl sulfide (DMS), a gas produced when microscopic animals graze on algae near the ocean surface. DMS acts as a "dinner bell" for tube-nosed seabirds like albatrosses, petrels, and shearwaters, indicating the presence of prey.

Matthew Savoca, a University of California, Davis graduate student, led a study to understand this association. They submerged mesh bags of plastic beads in seawater for a month and found that the beads acquired a DMS signature, emitting significant amounts of DMS at concentrations similar to plankton. This discovery suggests that the DMS produced by algae on plastic debris may confuse seabirds into mistaking plastic for food.

The study analyzed data from 55 studies of 25 different species of tube-nosed seabirds and confirmed that species responsive to DMS, such as Blue Petrels and Short-tailed Shearwaters, are more likely to ingest plastic. Seabirds that nest in burrows, such as the burrow-nesting albatrosses, petrels, and shearwaters, are also more vulnerable to plastic ingestion due to their increased reliance on their sense of smell.

The olfactory regions of these birds' brains are highly developed due to their extended nestling period in near-complete darkness, making them particularly susceptible to the scent cues of DMS-producing plastics. This knowledge underscores the importance of reducing plastic pollution in our oceans to protect the health and survival of seabirds and other marine life.

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