Special issue: Wetlands

insect-eating pitcher plants in an Irish bog

Marshes, billabongs, mangroves, fens, bayous, mires, swamps, deltas, and bogs. What do these places all have in common? They’re all wetlands.


This issue of Explorer magazine is going to tell you a lot about wetlands and why our planet depends on them. But first, let’s learn some basics.


What is a wetland? It’s an area of land that is entirely covered by water for at least part of the year. Wetlands are transition zones. They are neither totally dry land nor totally underwater; they have characteristics of both. The water can be saltwater, freshwater, or brackisha mixture of saltwater and freshwater.

You’ll find wetlands on every continent except Antarctica. They vary in size, and they can be very different from each other. Some are flooded woodlands. Others are flat, watery grasslands. Still others are choked by thick, spongy mosses. Yet, all wetlands are distinct ecosystems that teem with life. And they are vital to Earth.


Wetlands act as water filters. They prevent floods and erosion. They provide food and homes for fish and wildlife. They absorb nutrients, sediment, and pollutants before they reach rivers, lakes, and oceans.

a small marsh village in the Philippines

a mangrove forest in Brazil

As important as they are, wetlands are under threat across the world. People are draining, dredging, damming, and channeling them. They are converting wetlands into cropland, pasture, and places for housing. They are using them for dumping grounds for waste and sewage. And when people aren’t interfering with them, climate change is. Climate change can bring floods or droughts. It can increase water temperatures, killing wetland plants and animals.


In this issue, we’ll take a guided tour of some wetlands. Our National Geographic Explorers will help you understand the beauty and power of our world’s wetlands and the challenges we all face to protect them.

Brenna Maloney, managing editor, Explorer