HARMFUL ALGAL BLOOMS AND TOXIN PRODUCTION IN GEORGIA PONDS

Cyanobacterial toxins have been implicated in fish, wildlife, livestock and human mortality events. Cyanobacteria blooms, which often produce toxins, are exacerbated by hot, dry weather. The majority of Georgia, with the exception of the coastal Plain and the Northwest- ern corner, is currently in severe to exceptional drought conditions. In May 2012 we began receiving reports of livestock deaths associated with algal blooms. Based on clinical signs and algal screening, we documented four cattle deaths at one central Georgia pond with a dense Mi- crocystis aeruginosa bloom (4.4 x10 6 cells/mL) and mi- crocystin (i.e. algal produced toxin) concentrations in ex- cess of 142 ppb. Since this incident, we received and screened numerous water samples from livestock drinking water ponds throughout the state. We documented cya- noblooms, predominantly Microcystis aeruginosa, in the majority of ponds screened (11/14) and microcystins were present in the majority of samples screened for toxin (7/9). The livestock deaths have highlighted an important issue for Georgia farmers and pond owners that will likely be increasingly prevalent under projected climatic models. We have continued our outreach effort by establishing an official algal screening and cyanotoxin testing service through the existing Agricultural and Environmental Ser- vices Laboratories at UGA. This testing service will ena- ble us to better serve the citizens of our state and provide a platform to disseminate information aimed at improving water resource management.