Pelicans In Peril: Understanding Pollution's Impact

Pelicans are large water birds characterised by a long beak and a large throat pouch used for catching prey. They are gregarious birds, travelling in flocks, hunting cooperatively, and breeding colonially. They are also highly susceptible to pollution.

Pelicans, along with cormorants, are among the birds most affected by human disturbance and environmental pollution, particularly by chlorinated pesticides such as DDT and dieldrin. Pelicans and humans have a long history of association, and freshwater pelican species are vulnerable to habitat loss and pollution. Fishermen have persecuted pelicans and other fish-eating birds in times of low fish catch, but most studies indicate that the take by pelicans is primarily of non-commercial fish.

In addition to oil pollution, pelicans are threatened by reduced prey availability, hurricanes, global climate change, rising sea levels, offshore wind development, entanglement in fishing lines, and numerous other factors. A 2015 study found that nine out of every 10 seabirds have plastic in their stomachs.

Oil spills

The 2010 Deepwater Horizon oil spill, for example, killed an estimated one out of every 10 brown pelicans in the Gulf of Mexico. The spill also placed the eastern brown pelican, which primarily nests in Louisiana, back in grave danger just months after it had been removed from the endangered species list.

In addition to oil spills, pelicans face threats from plastic pollution, including fishing lines and nets, which can entangle and injure birds. Pelicans and other seabirds may also mistake plastic items for food, leading to starvation. Oil spills and plastic pollution can have devastating effects on pelican populations and highlight the importance of conservation efforts to protect these vulnerable birds.

Plastic pollution

Pelicans are vulnerable to plastic pollution in their marine environment, particularly from discarded fishing gear. Fishing nets, ropes, and pots made from plastic can entangle and trap pelicans, leading to starvation, injury, and increased vulnerability to predators. In California, rehabilitators treated nearly 3,000 aquatic birds, including many pelicans, for fishing gear-related injuries over a 13-year period. Pelicans can also mistake small plastic fragments for food, leading to ingestion and toxic contamination. Microplastics, in particular, are invisible to the naked eye, making it easy for pelicans to consume them. These microplastics can adsorb toxins, which then transfer to the fatty tissues of the birds. Additionally, larger plastic items can smother and break coral reefs, impacting the pelican's marine habitat and food sources.

The impact of plastic pollution on pelicans highlights the broader issue of plastic's harmful effects on nature. Plastic does not degrade and can persist for hundreds or even thousands of years. It escapes into natural environments, from the oceans to the tops of mountains, disrupting the cycles of renewal that natural ecosystems depend on.

Addressing plastic pollution requires a systemic transformation and a shift in how we view and use plastic. This includes improving waste management, recycling, and product design, as well as reducing the manufacturing and use of unnecessary single-use plastics.

Pesticides

Pelicans are among the birds most affected by human disturbance and environmental pollution, particularly by chlorinated pesticides such as DDT and dieldrin. Pelicans and humans have long been associated, and freshwater pelican species are vulnerable to habitat loss and pollution. Fishermen have persecuted pelicans and other fish-eating birds in times of low fish catch, but most studies indicate that the take by pelicans is primarily of non-commercial fish.

Pesticide contamination of the marine food web led to drastic reductions in brown pelican populations throughout their range in the mid-20th century. However, pollution abatement and environmental protection efforts have allowed populations to recover. Pelicans now serve as an icon for conservation success, but many populations are still under threat.

Fishing lines

In Florida, biologists have reported that fishing lines kill more pelicans than any other hazard. The Sunshine Skyway pier in particular has been identified as a site where a large number of pelicans become entangled. Over the past two years, more than 2,300 pelicans have had to be rescued from entanglement at this location, prompting discussions between bird advocates and fishermen to find solutions.

The Florida Fish and Wildlife Conservation Commission has implemented measures to reduce the number of pelican entanglements. These include educational requirements for anglers, prohibiting the use of multi-hook rigs during certain months, and limiting the number of hook-and-line gear anglers can use simultaneously. However, some bird advocates believe that more stringent measures are necessary, such as banning fishing during busy winter months or hiring full-time rescuers.

The problem of pelican entanglement is not limited to Florida. In California, for example, rehabilitators at just two wildlife clinics treated at least 2,957 aquatic birds for fishing-gear-related injuries from 2002 to 2015, with pelicans and gulls being the most common patients. The majority of these incidents are avoidable, and proper disposal of fishing lines and education for anglers are key to reducing the impact on pelican populations.

To address this issue, efforts are being made to increase the availability of monofilament recycling bins at popular fishing locations and to educate anglers on responsible disposal practices. Additionally, programs such as the California Lost Fishing Gear Recovery Project employ divers to clean up trash-filled fishing sites, removing monofilament lines and other debris that can harm pelicans and other wildlife.

Climate change

Pelicans are among the birds most affected by environmental pollution, particularly by chlorinated pesticides such as DDT and dieldrin. Pesticide contamination of the marine food web led to drastic reductions in brown pelican populations throughout their range in the mid-20th century. The eastern brown pelican, for example, was nearly driven to extinction by nest failure caused by organochlorine pesticides in the early 1970s.

In addition to pesticide pollution, pelicans are threatened by oil spills, plastic pollution, and entanglement in fishing lines. Oil spills can cause their feathers to absorb water, leading to drowning or hypothermia. It is estimated that 82,000 birds were killed in the 2010 Deepwater Horizon oil spill, including one out of every 10 brown pelicans in the Gulf of Mexico.

Plastic pollution, such as lost or abandoned fishing lines, can injure and kill hundreds of species, including pelicans. Birds can become entangled in the lines, leading to loss of limbs or strangulation. They may also mistake plastic items for food, leading to starvation. A 2015 study found that nine out of every 10 seabirds have plastic in their stomachs.

The effects of climate change, such as rising sea levels and reduced prey availability, also pose a threat to pelican populations. Additionally, pelicans are sensitive to changes in temperature and food supply, which can impact their breeding patterns.

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