Ocean Breathing

INTRODUCTION

Plastic has transformed modern life, but its durability has created a pollution problem that extends from cities and rivers to coastlines, the open ocean and the deep sea.

Once plastic enters the marine environment, it does not behave like most natural materials. Larger objects can persist for long periods while sunlight, waves, heat and physical abrasion gradually fragment them into increasingly smaller pieces.

Plastic particles smaller than 5 millimetres are generally called microplastics. Some enter the environment already small, while others form as larger products, packaging, fishing gear, synthetic fibres and other materials break apart.

The ocean also receives many other pollutants. Industrial chemicals, pesticides, excess nutrients, wastewater, oil and persistent contaminants can enter marine ecosystems through rivers, atmospheric transport, coastal development, shipping and direct discharge.

Pollution therefore exists at many scales — from fishing nets visible at the surface to microscopic particles and dissolved chemicals that cannot be seen at all.

Because ocean currents transport pollution across enormous distances, waste released in one place can eventually affect ecosystems far from its original source.

NOAA documents plastic fragmentation and the widespread distribution of microplastics throughout marine environments. marinedebris.noaa.gov

WHY IT MATTERS

Marine animals can become entangled in plastic debris. Lost fishing gear, ropes, packaging and other materials can injure, trap or kill wildlife.

Plastic can be mistaken for food. Marine organisms ranging from small animals to seabirds, turtles and larger species can ingest plastic debris.

Microplastics are difficult to remove once dispersed. Their small size allows them to spread through surface waters, sediments, polar environments and marine food webs.

Pollution does not respect national borders. Rivers, winds and ocean currents transport debris and contaminants far from where they originally entered the environment.

Some chemicals persist and accumulate. Persistent organic pollutants can resist degradation, travel long distances and accumulate in the tissues of living organisms.

Pollution adds pressure to ecosystems already affected by climate change, habitat loss and overexploitation. Reducing pollution can therefore improve the overall resilience of marine ecosystems.

Preventing pollution before it enters the environment is generally far more effective than attempting to recover widely dispersed material later.

NOAA describes marine debris as one of the most widespread pollution problems affecting the ocean, while UNEP documents the persistence and bioaccumulation characteristics of persistent organic pollutants. National Ocean Service

KEY FACTS

An estimated 19–23 million tonnes of plastic waste leak into aquatic ecosystems each year.

An estimated 75–199 million tonnes of plastic are already present in the ocean.

Microplastics are plastic particles smaller than 5 millimetres.

Microplastics come from many sources. They include fragments of larger plastic products, industrial pellets, synthetic fibres and particles generated through wear and use.

Microplastics have been found across the planet. They occur from tropical waters to polar ice and have also been detected in freshwater, air, food and drinking water.

Ocean garbage patches are not floating islands of solid trash. Debris is widely dispersed through the water, and much of it can consist of small pieces and microplastics that are difficult to see.

Human-health questions remain under investigation. Human exposure to microplastics occurs, but significant uncertainties remain about the health implications of different particle sizes, materials and exposure pathways.

UNEP provides the current 19–23 million tonnes per year and 75–199 million tonnes estimates. NOAA defines microplastics as particles under 5 mm and explains their distribution. WHO identifies important remaining uncertainties regarding human-health effects. UNEP - UN Environment Programme

Main Threats

Single-use and poorly managed plastic waste. Packaging, bags, bottles, food containers and other discarded products can enter waterways when waste-management systems fail or litter is transported by wind and stormwater.

Lost and abandoned fishing gear. Nets, lines and traps can continue catching or entangling marine animals after they have been lost at sea.

Microplastic fragmentation. Larger plastic debris gradually breaks into smaller pieces, making recovery increasingly difficult.

Synthetic fibres and wear particles. Clothing, fishing equipment and other synthetic materials can release microscopic fibres, while products such as tyres generate particles during normal use.

Chemical pollution. Persistent chemicals can remain in the environment for long periods, travel large distances and accumulate within organisms.

Wastewater and runoff. Rivers and drainage systems can transport plastics, chemicals, nutrients and other contaminants from inland areas to coastal waters.

Excess nutrient pollution. Fertilizer and wastewater inputs can stimulate excessive algal growth. Decomposition of this material can consume oxygen and contribute to low-oxygen coastal waters.

The accumulation problem. Continued inputs matter because many plastics persist rather than disappearing. Without prevention, pollution can continue accumulating even while cleanup efforts are underway.

NOAA identifies stormwater, inadequate waste handling and fragmentation among important pathways and processes for plastic marine debris.

SOLUTIONS

Prevent pollution at the source. The most effective strategy is to stop unnecessary plastics and hazardous pollutants from entering the environment in the first place.

Reduce unnecessary and problematic plastic products. Product redesign, reuse systems and alternatives can reduce demand for short-lived products that generate persistent waste.

Improve waste collection and management. Reliable collection, recycling where appropriate and safe disposal can prevent waste from leaking into rivers, coastlines and the ocean.

Design products for a circular economy. Products should increasingly be designed for durability, reuse, repair and recovery rather than becoming waste after a short period of use.

Improve wastewater and stormwater treatment. Better infrastructure can reduce plastics, fibres, nutrients and chemical contaminants reaching waterways.

Prevent and recover lost fishing gear. Gear marking, retrieval programs, improved management and fishing-industry cooperation can reduce abandoned gear.

Control hazardous chemicals. International regulation, safer chemical design and stronger pollution controls can reduce persistent contaminants entering marine ecosystems.

Target cleanup where it works. Beach, river and harbour cleanup can remove concentrated debris and prevent some material from reaching the open ocean. Cleanup is useful, but it cannot replace prevention.

Improve monitoring and research. Standardized measurements are needed to understand where microplastics and chemicals originate, how they move through ecosystems and which interventions work best.

The long-term solution is therefore not simply cleaning the ocean. It is redesigning the systems that allow pollution to reach it.

UNEP emphasizes waste prevention, improved management and a transition toward a more resource-efficient circular economy, while NOAA stresses prevention because fragmented plastics become extremely difficult to remove.

WHAT YOU CAN DO

Reduce unnecessary single-use plastics. Reusable products can reduce demand for items designed to be discarded after only a short period of use.

Dispose of waste responsibly. Litter dropped far from the coast can still travel through storm drains and rivers before reaching the ocean.

Avoid releasing plastics into drains and waterways. Small pieces can be difficult or impossible to recover once they enter aquatic environments.

Reduce synthetic microfibre pollution where practical. Keeping clothing longer, washing only when needed and choosing durable materials can help reduce unnecessary fibre shedding and consumption.

Participate in local cleanups. Removing debris from beaches, rivers and coastlines can prevent some material from being transported farther into marine environments.

Support better waste infrastructure. Individual behaviour alone cannot solve plastic pollution. Collection systems, product standards, wastewater infrastructure and producer responsibility all matter.

Support policies that prevent pollution upstream. Effective solutions can include reducing unnecessary plastic production, improving product design and controlling hazardous chemicals.

Be careful with health claims. Microplastics have been detected in food, water and air, but scientists are still determining what different levels and types of exposure mean for human health.

Focus on prevention rather than fear. The environmental case for reducing plastic pollution is already strong even while researchers continue investigating its full effects on human health.

WHO has called both for reducing plastic pollution and for more research to resolve uncertainties around human exposure and health effects. Verdenssundhedsorganisationen

SOURCES

UN Environment Programme — Plastic Pollution and Marine Litter
Global overview of plastic leakage, environmental impacts and strategies for reducing marine plastic pollution. UNEP - UN Environment Programme

UNEP — Plastic Pollution and Marine Litter

NOAA Marine Debris Program — Plastic
Explains how plastics enter marine environments, persist and fragment into progressively smaller pieces. marinedebris.noaa.gov

NOAA — Plastic Marine Debris

NOAA Marine Debris Program — Microplastics
Overview of microplastic definitions, sources, fibres, fragmentation and environmental distribution. marinedebris.noaa.gov

NOAA — Microplastics

NOAA — What Is Marine Debris?
Overview of how marine debris moves through the ocean and why accumulation zones are not literal floating islands of garbage. NOAA

NOAA — What Is Marine Debris?

UNEP / GESAMP — Sources, Fate and Effects of Microplastics in the Marine Environment
Scientific assessment of microplastic sources, distribution, environmental behaviour and potential ecological effects. UNEP - UN Environment Programme

UNEP — Global Microplastics Assessment

World Health Organization — Dietary and Inhalation Exposure to Nano- and Microplastic Particles
WHO assessment of human exposure, potential health implications and important remaining research gaps.

Plastic, Microplastics & Chemical Pollution