Louisiana Environmental Action Network

"Dead Bird Island"

Testing Results
Report by: Wilma Subra

Results of sampling performed by the Lower Mississippi Riverkeeper in Terrebonne Bay on August 19, 2010
On August 19, 2010, in Terrebonne Bay south of Point-au-Chien, Modato Island was covered with vegetation, bare areas, and a large number of dead shore birds.  The area was designated by the Lower Mississippi River Keeper as "Dead Bird Island."  The area also contained a number of shore birds in distress, nests containing eggs and a seagull that died shortly after sampling was complete.  Samples were collected along the shore of the island, 10-12 inches deep, under the vegetation matted material washed in by the tide.  The soil/sediment sample was contaminated with 48.4 mg/kg of Petroleum Hydrocarbons and 10 Polynuclear Aromatic Hydrocarbons (0.039 mg/kg).

Dead Tern - A dead gull found on "dead bird island" from which samples were taken

The internal organs from a gull, found dead, on the island contained 23,302 mg/kg Petroleum Hydrocarbons (2.3%).  The Blue Crab and Hermit Crab contained 3,583 mg/kg Petroleum Hydrocarbons and 4 PAHs (0.162 mg/kg).

At the southwest end of Modato Island the sediment/soil was contaminated with higher concentrations of Petroleum Hydrocarbons and Polynuclear Aromatic Hydrocarbons (PAHs), 68.3 mg/kg Petroleum Hydrocarbons and 14 Polynuclear Aromatic Hydrocarbons (0.051 mg/kg).

Hermit Crab - A hermit crab in a welk shell on Modato island

On the north shoreline of Lake Chien, a boom was located 40 feet in from the shore in wetlands vegetation near the high water debris mark.   In the wetlands vegetation near the high water debris mark, the soil/sediment was contaminated with 0.039 mg/kg of 18 Polynuclear Aromatic Hydrocarbons. The Fiddler Crab and Snail from this area contained 6,916 mg/kg Petroleum Hydrocarbons and 1 PAH (0.012 mg/kg).

The marsh  grass along the shoreline of Lake Chien contained 3,946 mg/kg Petroleum Hydrocarbons and 10 PAHs (0.326 mg/kg).