Reflection in the wetlands.  (I emailed the &quot;Friends of Blackwater&quot; to find out what purpose these posts serve -- there are a lot of them throughout the refuge.  Here's the answer I received from Martin O'Connor, the president of the organization: &quot;We have lost about 8000 acres of marshland due to nutria and other factors and several experimental rebuilding plots have been done where the bottom of the marsh is raised somewhat and then replanted.  The posts you saw in the wetlands were to support netting to protect the replanted reeds from Canada geese and other wetland vegetation eaters.  This allowed the vegetation to get established.  These programs have been successful and in the next few years more extensive experimental restoration of the marshes will be done.&quot; [ http://www.friendsofblackwater.org/])