Did you know that we have at least four common types of coastal wetlands? Each differs due to dissimilarities in water regime, landscape, vegetation, soils, climate, and more.

These coastal inhabitants are too valuable to lose. Unfortunately, they are currently disappearing three times faster than forests.

Coastal wetlands provide important benefits, such as filtering our water and protecting communities from floods
Coastal wetlands provide important benefits, such as filtering our water and protecting communities from floods

Keep reading for simple descriptions of the four common types of coastal wetlands, their benefits to humans, and what you can do to save them.

Mangrove Swamps

Major Feature: Mangrove trees that grow above the shoreline

Impact on the Environment?: 3-to-5 times more efficient carbon sinks than tropical forests

Everglades mangrove swamp
Everglades mangrove swamp

Like all coastal wetlands, mangrove swamps are saturated with water, and plants that tolerate wet soils and low oxygen levels characterize them.

A significant feature of these swamps is the tangled, clumped roots of mangrove trees that grow above the shorelines. They enable the wetlands to buffer coastlines successfully from currents, waves, storm surges, and tides. At the same time, these plants provide the most suitable nursery grounds for some shark species, groupers, and snappers.

 If that’s not enough, imagine how much the tangled, clumped roots protect small fish from predators.

Besides being some of the best coastal wetlands, mangrove swamps are 3-to-5 times more efficient carbon sinks than tropical forests.

Seagrass Wet Meadows

Major Feature: Seagrass growing underwater

Impact on the Environment?: Absorbs about 10% of the carbon sequestered in the ocean

Mixed seagrass meadow
Mixed seagrass meadow

There are many types of wet meadows, and seagrass meadows are one of the most common ones – it’s characterized by seagrass- another plant with a high ability to tolerate moist soils and low Oxygen levels.

Seagrass grows underwater, creating an ecosystem that serves as a suitable nursery ground for wildlife and fish species. Like mangrove swamps, these meadows also help minimize the adverse impact of climate change and reduce soil erosion.

Moreover, the wetland absorbs approximately 10% of the carbon sequestered in the ocean.

Salt Marshes

Major Feature: Saltwater that floods as tides come in

Impact on the Environment?: Arbsorb plenty of water and extract carbon from the atmosphere.

Salt marsh
Salt marsh

Salt marshes are one of the four common types of coastal wetlands found worldwide, particularly in temperate regions. As tides come in, saltwater floods them.

Salt marshes are home to plenty of birds, invertebrates, and fish, making them an outstanding contributor to local economies and fisheries.

The unique ability of salt marshes to absorb plenty of water is one of the reasons it has made it into the list of the four common types of wetlands. This reduces flooding in the coastal areas, thereby protecting the local communities from disasters.

Moreover, like seagrass beds and mangrove swamps, salt marshes extract carbon from the atmosphere and store it safely.

Freshwater Marshes

Major Feature: Shallow water and mineral soils

Impact on the Environment?: Protect the coastal lines from flooding and storms

Crocodiles living in a freshwater marsh
Crocodiles living in a freshwater marsh

According to the National Oceanic and Fisheries Administration (NOAA), freshwater marshes feature among the four common types of coastal wetlands. Periodic or permanent shallow water and mineral soils characterize these coastal wetlands.

Freshwater marshes typically get most of their supplies from surface water, including runoffs from the ocean and floods. However, they derive some water from underground sources as well.  

Plants and animals that aren’t tolerant to salt thrive in these wetlands. Besides offering an essential nursery and rich feeding ground for numerous marine species, they protect the coastal lines from flooding and storms.

3 Benefits of Coastal Wetlands

We’ve discussed the benefits of the four common types of coastal wetlands under each category above to make comparisons easy. In this section, we’ll briefly discuss a few unique benefits and expound a little further on one or two that we’ve already mentioned.

Here are some of the top benefits:

  1. Support sustainable fisheries: Your favorite seafood considers wetlands the safest places to feed, reproduce, and live. In 2018, the US contributed $238 billion in sales and supported 1.7 million jobs. Without wetlands, there would be no fish in the ocean.
  2. Clean water: Coastal wetlands are natural water purifiers. They trap and filter impurities from runoff and agricultural activities. That’s how wetlands can help you to maintain beautiful beaches.
  3. Store coastal blue carbon: Most coastal wetlands remove greenhouse gases from the atmosphere and store them in the soil and plants. By doing this, they minimize the harmful effects of pollution.

Coastal Wetlands: Too Valuable to Lose

We have seen why the four types of coastal wetlands are too valuable to lose. So, what should we do to stop these coastal habitats from disappearing three times faster than forests? Start restoring wetlands, addressing pollution, and using wetlands wisely.


What are wetlands?

Wetlands are distinct ecosystems that are permanently or seasonally saturated with water. All types of wetlands are characterized by plants that tolerate low oxygen levels and wet soils. Coastal wetlands are found in the region in which tidal streams drain to the inland seas or the ocean. Salt marshes, seagrass beds, freshwater marshes, and mangrove swamps are some of the most common coastal wetlands.

What are the challenges that the four common types of coastal wetlands face today?

One of the main challenges the four common types of coastal wetlands face today is habitat loss. Most coastal watersheds lose vast chunks of land to erosion, drainage, development, sea-level rise, and subsistence. The next major one is human activities. Humans alter coastal habitats for selfish reasons, and this trend has led to the degradation, disappearance, and disconnection of many wetlands worldwide. The effects of climate change also pose a significant threat to these resources.

Can wetlands purify wastewater?

Wetlands can treat wastewater in some instances. When water flows through a wetland, the tangled, clumped roots of the growing plants remove large plastics and other unwanted materials from the water. This process helps to keep the ocean plastic-free. However, unless more is done, coastal wetlands can’t remove some pollutants and nutrients naturally from the water.

How do wetlands protect coastal lands from flooding?

Plants that grow in coastal wetlands can efficiently hold back some flood waters or reduce the speed at which they enter the ocean. Thus, they are good at reducing the severity of soil erosion and downstream flooding. Statistics show that flood peaks may increase to 80% in some watersheds where wetlands have been lost.

Why are salt marshes marshy?

Salt marshes are marshy because the soils are often peat and deep mud. Saltwater marshes are also called saltwater wetlands. To know more about these wetlands and why they are marshy, please remember that ocean tides bring the salt water that floods and drains them, and the floods can collect soil from anywhere, including the deep mud.

About Ocean Info

At Ocean Info, we dive deep into ocean-related topics such as sealife, exploration of the sea, rivers, areas of geographical importance, sailing, and more.

We achieve this by having the best team create content - this ranges from marine experts, trained scuba divers, marine-related enthusiasts, and more.

Sea Anemone with Clownfish

Dive into more, the ocean is more than just a surface view

Bottlenose dolphins are known to help stranded humans back to the shore

8 of the Most Intelligent Marine Animals

From dolphins' awe-inspiring communication skills to orcas' social complexity, the ocean is home to some of the most intelligent marine animals.

Share to...