This past summer, we saw two papers presented at the national Aquatic Plant Management Society linking a species of blue green algae that grows on Hydrilla (a class A noxious weed) and the death of Eagles. This species of algae grows on the Hydrilla that is infesting lakes and reservoirs throughout the Southeast. Waterfowl such as American Coots and other eat the hydrilla, it’s their primary food source in a lake run over with this plant. The toxin caused a brain wasting disease much like Mad Cow Disease. As this incapacitated the birds, they become easy prey for the Bald Eagle. This toxin magnifies up the food chain, like the second coming of Rachael Carson’s Silent Spring.
This is a good public domain article that discusses the problem. http://thetandd.com/lifestyles/poisonous-pest-hydrilla-doing-more-than-clogging-lakes/article_877f6172-383f-11e3-bfab-001a4bcf887a.html
Here are a few more: