第33章　海洋プラスチック汚染

Most of the surface of our planet is covered by ocean. The seas surround every continent, and they play a quiet but vital role in shaping the global climate. Without the ocean, life on land could not exist for long.

In recent decades, however, our seas have been ruined by an extraordinary amount of plastic waste. Every year, plenty of garbage is washed into streams and rivers, and from there it flows steadily into the sea, where it joins an already enormous mass of floating trash.

Plastic does not simply disappear. Under the action of sun and salt, it slowly breaks down into tiny particles, but it does not return to nature. Some of these particles float on the surface of the sea; others spread through every layer of water before sinking to the deep ocean floor.

Tide and ocean currents then carry the waste in every direction. Beaches that were once clean now collect bottles and broken nets from coasts hundreds of kilometers away. Almost no shoreline today is an exception to this trend.

Severe storms and sudden floods make the problem much worse. A single flood can sweep huge quantities of garbage from a city into the sea in a few hours, and a changing climate is making such weather events more frequent.

The damage to wildlife is heartbreaking. Many marine animals swallow small bits of plastic and slowly die, while seals and whales sometimes drown when caught in fishing nets. Tiny particles can also infect fish, and through them eventually reach our own dinner tables.

Even the most remote parts of the ocean are no longer safe. Sailors aboard a small vessel far from any port report seeing floating bottles every day. Coral reefs around the world have been devastated by repeated waves of plastic waste. What can be done? Governments and ordinary citizens must work together to reduce plastic, to remove waste already in the water, and to refuse to ruin one of the planet's greatest treasures. A sea full of sinking trash is not a future any child deserves.