ST. PETERSBURG, Fla. -- An independent investigation into the die-off of pelicans at Coffee Pot Bayou and a lake near Rivera Bay in January concluded that water temperatures, oversaturation of nutrients in the water ecosystem and the reemergence of a powerful neurotoxin likely contributed to the deaths of 70 birds and sickened many others.

Arcadis, who conducted the nearly three-month investigation, released its final report Monday morning. You can read the report in its entirety at this link or below.

According to the report, the warm water temperature conditions at both locations were interrupted by a drop in temperature on January 8 which was followed by cool rains until January 10. Scientists said that this plus an "excessive amount" of nutrients within the water contributed to a large algal bloom which deprived the water of oxygen.

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These conditions spurred a rise in the neurotoxin Clostridium botulinium, within the algae. The fish which ate the algae became infected with the bacteria, which also caused a massive fish kill. Despite what the investigation called a "quick response" by the City of St. Petersburg to the fish kill, officials were not able to prevent pelicans from consuming the dead fish.

The report said that the pelicans who died at Coffee Pot Bayou likely consumed the infected fish from the Rivera Bay location before flying back to Coffee Pot Bayou.

Arcadis recommended further study of the conditions at Rivera Lake No. 1 and for the city to eliminate reclaimed water from entering the lake. They also asked for the installation of aerators to run during winter rain events to prevent the reemergence of bacteria and the prompt response and removal of dead fish from the lake.

Pelican and Fish Mortality Report Final by webdept10 on Scribd