Island Ecology for Educators 2020

Salt Marsh

Jackie Waple

Introduction

A salt marsh is a type of coastal wetland that has been flooded and drained by the tides. They are composed of deep mud, peat, and similar soils containing a great deal of decomposing materials. Most of the time they are flooded by the tide and contain very low levels of oxygen - this gives the salt marsh area its infamous rotten egg smell.

This transition from ocean to land though smelly, is extremely nutrient-rich. The tides bring with them nutrients from the ocean and carry away waste materials that become food for fish and other marine organisms. This ecosystem is considered among the most productive on earth. It’s where saltwater and freshwater meet and plant life thrives. Salt marshes are also amazing natural filtration systems.

Issues, Human Impacts, and Conservation

Salt marshes are immensely valuable ecosystems. They are habitats for countless organisms, bring nutrients upland, and filter toxins from the water. Though they are fantastic filters, they are struggling to keep up with agricultural runoff. Fertilizers used in farming and sewage-laden runoff are being found in the marshes and creating a massive issue. These nutrients are creating an even lower level of oxygen than usual which is killing off fish and shellfish and altering the growth of the flora.

Other human impacts such as construction, overfishing, climate change, and the introduction of invasive species are to blame for the degradation of this ecosystem. It is sensitive to these changes and we are quickly seeing the effects.

Conservation is important. There are ways that many organizations are attempting to restore salt marshes. Efforts include removing invasive species, removing levees, and attempting to re-establish biodiversity. Though helpful, this is expensive and labor-intensive. The best thing we can do is conserve the marshes we have.

Distribution Map and Ecological Features

Salt marshes are found on coasts all over the world, though they are primarily the east coast of the United States. They are the area of transition from the ocean to terrestrial land. They allow for the flow of nutrients back and forth from the ocean to land. They are extremely productive and vital parts of the coastal areas in which they were formed.

Image source

Flora and Fauna

The salt marsh ecosystem is extremely diverse. Animals such as hermit crabs, blue crabs, grass shrimp, and mussels thrive here. Along with these animals, plants such as saltgrass, woody glasswort, beach tea, and saltmarsh bullrush. These plants and animals live in synergy in this beautiful ecosystem.

Web Resources for Audience to Explore

Dynamics of the Salt Marsh - this is a very comprehensive explanation of energy flow in salt marshes.

Energy Flow Through an Ecosystem - this explanation of energy flow through ecosystems from national geographic will be helpful in your understanding of the dynamics of salt marshes.

Why Are Our Salt Marshes Falling Apart? - This will help you understand the ecological issues facing salt marshes. It’s important that you are aware that salt marshes need our help!

Love Your Island - 10 Facts about the Salt Marsh! - here you will find really interesting facts about salt marshes!

Salt Marsh Food Web - this website has some beautiful infographics about salt marshes!

Salt Marshes - NPS.gov - this is not only a great explanation of salt marshes, but you can also find up-to-date news about marshes!