Why water timing matters
The Ramsar Convention, signed in Ramsar, Iran, in 1971, defines wetlands broadly: marshes, fens, peatlands, rivers, lakes, mangroves and shallow coastal waters. What unites them is saturation. Plants rooted in waterlogged soil cope with low oxygen; animals time breeding to rising or falling water; nutrients are carried in and trapped. Ecologists call the seasonal rise and fall the "flood pulse", and in many large wetlands it is the single most important driver of life.
Three ways water builds a habitat
Okavango Delta and Pantanal
The Okavango Delta in Botswana, inscribed as a UNESCO World Heritage Site in 2014, is an inland delta that never reaches the sea. Rain falls in the Angolan highlands, and the floodwater takes months to arrive, peaking in Botswana's dry winter. Elephants, red lechwe and hippos concentrate as surrounding land dries. In the Pantanal, the annual flood spreads across grasslands, and when it retreats, fish are trapped in shrinking pools, feeding jabiru storks, caimans and giant otters. Traditional cattle ranching families, the pantaneiros, have long worked around these cycles.
Sundarbans and coastal forests
Mangroves live where fresh and salt water mix twice a day. The Sundarbans of Bangladesh and India form one of the largest mangrove forests in the world and are home to Bengal tigers adapted to swimming between islands. Mangrove roots trap sediment, build land, and shelter young fish and crabs that later support coastal fisheries. Honey collectors, the mawali, and fishing communities rely on the forest and hold detailed knowledge of its tides and dangers.
Peat bogs and fens
Where waterlogging slows decay, dead plant material accumulates as peat over thousands of years. Sphagnum mosses acidify the water and hold many times their weight in it. Carnivorous sundews and bog rosemary thrive in nutrient-poor conditions. The Flow Country of northern Scotland, a World Heritage Site since 2024, is one of the largest blanket bogs in the world. Drained peat releases stored carbon, so restoration often means blocking old ditches to raise the water table again.
The Everglades: a river of grass
Writer and activist Marjory Stoneman Douglas called the Everglades a "river of grass" in her 1947 book of the same name. Water once flowed slowly south from Lake Okeechobee across a vast sawgrass plain to Florida Bay. Canals and levees broke that sheet flow in the twentieth century, contributing to declines in wading-bird nesting and to saltwater intrusion. The Comprehensive Everglades Restoration Plan, authorised in 2000, aims to restore more natural water flow. It is a case study in how expensive it is to rebuild a water cycle once it is broken.
- Seasonal rain
- Sheet flow
- Periphyton mats
- Small fish
- Wading-bird colonies
Stewardship on the water's edge
Many of the world's best-functioning wetlands are also working landscapes. Rice farmers in the Camargue, reindeer herders around northern mires and fishers in the Inner Niger Delta all adjust to water levels. Effective conservation usually involves them: Ramsar's "wise use" principle explicitly recognises sustainable human use as compatible with protection.
Observation panel: visiting a wetland
- Use boardwalks; trampling compacts peat and crushes nests.
- Keep distance from wader colonies during breeding season.
- Check tide tables and listen to local boat operators.
- Join a monitoring day: water depth and bird counts are valuable data.