Marine plastic pollution, an umbrella term used to describe one of the 5 Major Threats to whales and dolphins identified by our ongoing research, encompasses all harmful human-made substances (debris or chemicals) that can have adverse effects on the ocean environment or its inhabitants. The most concerning issue regarding ocean pollution is the number of unknowns surrounding the effects it has on the marine ecosystem and the animals within.
Marine debris in the ocean can have serious negative impacts on the health and well-being of whales, dolphins and other marine life. Here are some of the ways pollution can affect these marine mammals:
Pollutants such as chemicals, heavy metals, and plastic debris can contaminate the animals’ food sources and water, leading to health problems and even death. Some chemicals can also accumulate in the animals’ tissues over time, leading to long-term health impacts.
Pollution can degrade the animals’ habitats by damaging coral reefs, seagrass beds, and other important marine ecosystems. This can reduce the availability of food and shelter for whales and dolphins, making it more difficult for them to survive.
Some debris can entangle whales and dolphins, causing injuries and even death. Entanglement can prevent the animals from swimming, feeding and breathing properly, and can also make them more vulnerable to predation.
Common debris items found along beaches, coastlines and in the water include disposable plastic food ware, cigarette butts and abandoned fishing gear. Due to its pervasive qualities, plastics are particularly concerning as sun, wind and waves eventually degrade larger pieces into progressively smaller and smaller fragments. Known as microplastics, these minuscule pollutants infiltrate the food chain endangering all marine life.
When smaller organisms feed on microplastics, associated toxins become absorbed in organic tissue. These toxins then move up the food chain, ultimately contaminating whales, dolphins and other marine mammals as well as the global seafood supply. A chief concern regarding ocean pollution is the degree of uncertainty regarding its cumulative impact on marine ecosystems and wildlife.
The ocean also now contains large quantities of persistent organic pollutants (POPs). POPs include polychlorinated biphenyls (PCBs), brominated flame retardants and organochlorine pesticides. POPs build up through the food chain (i.e., bioaccumulate) putting top predators such as cetaceans (whales and dolphins) at greatest risk due to the aggregate quantity ingested by prey. When food is scarce, whales and dolphins tend to break down stored blubber for energy, releasing a flood of toxic chemicals into their bodies.
What We Don’t Know
Few scientific studies have been conducted on how chemicals from oil spills affect the bodies of wild dolphins and whales. However, two orca populations have not recovered from the Exxon Valdez oil spill in Prince William Sound, Alaska, in 1989. Ongoing studies are looking at the effects of the huge 2011 oil spill in the Gulf of Mexico; already the Barataria Bay bottlenose dolphins near Louisiana are showing signs of severe ill health.
POPs are not only harmful to the health of marine organisms and their environment. These toxins can be transported over long distances by wind and water currents, which means that even POPs generated in one country can affect marine wildlife in distant regions. POPs persist for extended periods in the environment with unknown long-term effects on cetacean wellness.
Regardless of where one lives, whether seaside or land-locked, improperly discarded trash can enter lakes, rivers, streams and other waterways with the strong potential of making its way to the ocean. It’s up to all of us to do our part in reducing the staggering amount of debris polluting our planet.
Monitoring Marine Debris
We research marine debris’ impact on marine mammals and conduct conservation programs and beach cleanup events enlisting community scientists (volunteers) to collect and record debris along Maui’s coastlines—vital data used to influence legislation and public awareness.
Pacific Whale Foundation (PWF) initiated dedicated marine debris research in 2013 to better understand its effect on Maui’s marine environment and the impact of education, policy and outreach on mitigation efforts.
In 2015 we piloted the Coastal Marine Debris Monitoring Program (CMDMP) encouraging residents and visitors to collect and record coastal debris used to inform legislation and public awareness.
In 2021 alone, CMDMP participants recorded more than 67,000 debris items, prompting the addition of a second program, Adopt a Beach. Adopt a Beach encourages Maui residents to commit to a monthly cleanup and debris documentation of a selected beach or shoreline for a 12-month period, with plans to expand the program to Neighbor Islands to further advance our mission to protect the ocean through science and advocacy and inspire environmental stewardship.
Humpback Whale Biopsy Sample Collection Efforts
As part of the Humpback Whale Sentinel Program (HWSP), PWF researchers collect biopsy samples from humpback whales in Ecuador to evaluate pollutants in Antarctic waters.
In partnership with research groups focused on varied southern hemisphere humpback whale breeding stocks, the HWSP will analyze biopsy samples provided by program participants. By supplying samples from breeding stock G, PWF is actively contributing to a worldwide comprehensive study of persistent organic pollutants in 80% of Antarctic humpback whale stocks.