Wetland Migration Barrier (image) Virginia Institute of Marine Science Share Print E-Mail Caption Barriers to wetland migration, such as this Dutch levee, are common in Europe and China. Credit © Rijkswaterstaat / Joop Van Houdt. Usage Restrictions One-time use only. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.