Louisiana Barrier Islands

Case Study: Louisiana Barrier Islands

Sea level rise and the increased erosion that results is a serious concern for barrier islands. NASA provides a quote from geoscience researcher Matthew Stutz that explains how every barrier island is unique:

“However, rising sea level is not just like pouring more water into a bathtub,” Stutz emphasized. Islands react differently based on the geology in a region and how the waves and tides in an area are affected. People tend to assume sea level rise means fewer islands no matter what, but the rate of rise is critical.”[footnoteRef:6] [6: Text by NASA is in the public domain]

Decreases in upstream sediment supplies from human activities such as dam construction also play a role in disappearing barrier islands, especially along the Mississippi Delta. The USGS explains that:

Louisiana’s barrier islands are eroding so quickly that according to some estimates they will disappear by the end of this century. Although there is little human habitation on these islands, their erosion may have a severe impact on the environment landward of the barriers. As the islands disintegrate, the vast system of sheltered wetlands along Louisiana’s delta plain are exposed to increasingly open Gulf conditions. Through the processes of increasing wave attack, salinity intrusion, storm surge, tidal range, and sediment transport, removal of the barrier islands may significantly accelerate deterioration of wetlands that have already experienced the greatest areal losses in the U.S. Because these wetlands are nurseries for many species of fish and shellfish, the loss of the barrier islands and the accelerated loss of the protected wetlands may have a profound impact in the billion dollar per year fishing industry supported by Louisiana’s fragile coastal environment.[footnoteRef:7] [7: Text by the USGS is in the public domain]

You may also find this video is helpful.

1. List the causes of barrier island destruction:

2. List the effects of barrier island destruction:

Let’s explore Louisiana’s barrier islands by comparing satellite imagery across multiple years.

Step 1

Go to Esri’s World Imagery Wayback website . Or, if you have Google Earth Pro you could look at the historical imagery in that program.

Step 2

In the search box, type Louisiana and click the magnifying glass.

Step 3

Zoom in on one of the barrier islands off the coast of Louisiana (pick any named island).

3. What is the name of the barrier island that you zoomed in on?

Step 4

Zoom in as far as you are able to.

Step 5

Click the “Only versions with local changes” box.

4. What is the date of the oldest imagery available?

5. What is the date of the most recent imagery available?

Step 6

Click on each date available to see how the barrier island landscape changed over time.

6. In two to three sentences, describe the changes that you observe.

7. Use Your Critical Thinking Skills: If the historical imagery at the barrier island that you selected went back 10, 50, or 100 years, what changes do you think you would have observed? Respond in one to two sentences.