San Cristobal (image) Smithsonian Share Print E-Mail Caption A cargo dock on San Cristóbal Island in the Galapagos. Manmade structures like docks can make it easier for nonnative marine species to thrive, by giving them a hard surface to grow on. Credit Inti Keith/Charles Darwin Foundation Usage Restrictions This image is available for media to use for educational, non-commercial purposes, provided the credit above is included. 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.