Response of Fish Assemblages in Southeastern Louisiana to the Deepwater Horizon Oil Spill and Subsequent Spill Prevention Measures with an Emphasis on Lemon Shark Nursery Habitats

The Nekton Research Laboratory at the University of New Orleans has been conducting fisheries independent scientific surveys of fish assemblages in southeastern Louisiana since 2003 with an emphasis on the Chandeleur Islands, Biloxi Marshes, Lake Borgne, and Lake Pontchartrain.  The 2010 Deepwater Horizon oil spill has made these data invaluable for determining the impact of oil and dispersants on commercially and recreationally important fisheries.  While the data are still being analyzed, at three sample sites during winter months there were no significant changes in assemblage composition when 2010 data were compared with baseline data (ANOSIM, Global R range = 0.037 – 0.580, p > 0.05).  In the past 5 years researchers have documented a large number of sub-adult lemon sharks (Negaprion brevirostris) at the Chandeleur Islands indicating these barrier islands are the northern most nursery ground for this species. During late summer of 2010, neonatal and juvenile sharks were captured and tagged in an effort to determine possible effects of the oil spill and prevention measures (e.g., berm construction) on their abundance and survival.