Wetlands

Table of Contents

Introduction

Wetlands are a critical part of our water cycle, protecting us from floods and storing water in aquifers which we can use for generations. 

Biodiversity

Wetlands host many species from common migratory birds and fish, to very rare and specialized species including mangrove plants and peatland insects. Amphibians, crabs, and many other call wetland home year-round, while others just use them as a stepping stone to distant breeding or feeding grounds.

Clean Water

The plants including mosses, grasses, and even trees can help clean our environment by filtering pollutants from the air and water. They help keep our groundwater clean, and prevent dangerous pollutants from reaching our oceans. 

Tall grasses can capture plastics that have washed into waterways, and a growing number of species have been found to help remove PFAS.

Type of Wetland

The following are some types of wetland, divided into coastal and inland examples. They are listed alphabetically. Some are permanent, while other examples may disappear and reappear depending on season or tides.

Coastal

Estuaries

These wetlands are characterized by the mixing of fresh and salt water. Different parts of the estuary will have different levels of salinity, which in turn means different plants in different areas, according to how salt tolerant they are. 

Migratory fish and birds rely heavily on these ecosystems, for example salmon fry which hatch up in mountain streams come down and spend time eating, growing, and gaining strength in estuaries before heading out to see. Where estuaries have been destroyed, and these young salmon are flushed directly out to sea, scientists have found they can stunted by the sudden shock of ocean water, making survival much harder than for those with the benefit of their historical transitional zones.

Mangroves

These coastal forests consist of trees that help protect coastlines from incoming storms including hurricanes and the flooding they produce. The trees are adapted to saline water, and are full of species who rely on brackish water including oysters and crabs.

Mangroves are under threat from shrimp farms, unsustainable oyster harvesting, as deforestation both for wood harvesting and livestock farming (mostly cattle).

Mudflats (Slob in Ireland)

These are found world wide, and support diverse ecosystems for crabs, sea birds, and fascinating species such the mud skipper, a fish that survives on land and breathes using water trapped inside their large gill chambers.

Salt Marsh

Also known as a coastal salt marsh. These coastal ecosystems are found in the upper interdental zone between land and open salt or brackish water. They are regularly flooded by tides.

Inland

Basin Wetlands

These are much like vernal pools, in that they can be seasonal, but can vary massively in size.

Freshwater Marsh

These can be found in a variety of landscapes including spaces along side estuaries, canals, rivers, lakes, or ponds.

Peatland

Also known as bogs and mires. These diverse ecosystems can support all sorts of species, including grassland and scrubland type plants, with rich layers of moss which help sequester greenhouse gases such as CO2. 

Around the world peatlands have been drained for agriculture, as well as harvested for mosses used in gardening. 

Pocosin

These are palustrine wetlands with deep, acidic, sandy, peatsoils. Groundwater saturates the soil except for short seasonal dry spells as well as prolonged droughts. Their soils are nutrient deficient, especially in phosphorus. - Wikipedia: Pocosin

Pocosins are characterized by dense, waxy shrub and woody vine vegetation. Sometimes they include sweet bay, loblolly bay, swamp bay, and pond pines. - Carolina Wetland Association: Types of Wetlands

Seeps

Seeps are created when ground water reaches the surface, and are defined by their unique proximity to slow moving ground water. They usually occur over an impermeable layer that prevents the water from draining, keeping the area wet for most of the year.

Swamps

These consist of trees suited to damp and wet growing conditions. A swamp might be vast and consist of waterways and lake-sized water bodies, or may only exist at one end of a lake, depending on the terrain and geological characteristics of an area.

Riparian Zone

These zones exist along the edges of waterways, helping to protect water quality, reduce erosion, and prevent damage from floods or even reducing flooding itself. These spaces provide rich habitat for wildlife and can act as wildlife corridors in otherwise urban or agricultural spaces.

Vernal Pools

These are seasonal pools or ponds, also called ephemeral pools. They are created by rainy weather, providing critical habitat for frogs and other species, then drying up and disapearing till the next adequate rain fall event.

Wet Meadow

These are often part of a larger complex that may include shrub swamps, forested swamps, and marshes.

Threats to Wetlands

This sections covers some of the threats to wetlands.

Agriculture

Drained Wetlands

Over the last 100 or so years, many wetlands have been drained for farming and urban expansion. We have turned around half of the planet's habitable land into farm land with 77% of that being used for livestock and their feed, while only around 1% of habitable land has been built up for urban or industrial purposes. 

In addition to draining wetlands for grazing, coastal wetlands such as mangroves have also been destroyed to make way for aquaculture, particularly shrimp farming.

Chemical Pollution

Humanity produces a ton of chemical pollutants, but farming releases many tons of raw animal sewage which is full of microplastics and PFAS from contaminated animal feed, and the majority of antibiotics which are used on livestock instead of for humans. In addition there are pesticides, synthetic fertilizers, fungicides, and various livestock medications including de-wormers. All of these impact aquatic ecosystems, particularly wetlands where these chemicals can accumulate, killing off fish, amphibians, often through their insect prey or simply via contaminated water itself.

Water Extraction

We all need water to live, and wetlands can help provide us with safe drinking water. However the amount used by agriculture and industries is increasingly unsustainable. By comparison people use very little water in and around their homes, but every little counts.

Click the Water button to learn which of our choices have the biggest impact on humanity's water use. Which small changes can save the most water, such as picking different foods or borrowing and reusing instead of buying new products. The page also touches on what at-home changes we can make, including the installation of rain barrels and grey water systems.

Deforestation

For the mangroves and other types of wetland that are characterized by trees, deforestation for farming and lumber are a grave threat. 

Sea Level Rise

As water levels rise, salt water intrudes deaper into mangroves, estuaries, and other coastal weltands, killing off the less salt-tollerant plants, often leaving dead trees to rot and give off greenhouse gases. When sealevel rise and flooding cause salt water to infiltrate fresh ground water, this can kill off entire coastal ecosystems including forests.

Light Pollution

Many species who dwell in and around wetlands rely on light to communicate, navigate, and find mates. These species include turtles, migratory birds, and fireflies. When nearby communities, tourists, and industries flood the area with artificial lights, they throw off these natural activities, causing baby turtles to get crushed on roads instead of swimming out to sea, preventing fireflies from finding mates, and causing migratory birds to get lost or even crash into buildings.

Benefits of Wetlands

Water Cycle: Drought & Flood Protection

Biodiversity

Wetland Species

Animals

Amphibians

Birds

Fish

Insects

Plants & Algae

Aquatic Plants

Resources & Guides

Europe

Scotland

Oceana

Australia

NSW

Queensland

Organizations

International

Africa

Cameroon

Chad

Libya

Mauritania

Senegal

Asia

Turkey

United Arab Emirates

Europe

Belgium

Czech Republic

Finland

French Southern & Antarctic Lands

Hungary

Ireland

Luxembourg

Netherlands

Poland

Romania

Sweden

United Kingdom

North America

Cuba

Haiti

USA

North Carolina

South Carolina

Oceana

Australia

Grants & Funding

Europe

UK

Scotland

North America

USA

Minnesota

Oceana

Australia

Western Australia