Invasive Species Week ! Feb 28-March 4 is Invasive Species Week! Pathways of Spread are routes by which an invasive species is transferred from one ecosystem to another. Below are some common pathways of spread. You can get involved by liking and sharing/retweeting posts created by participating organizations, or creating your own posts, using the hashtag #InvSpWk during ISAW. Learn more about invasive species awareness week !