Scientists with the St. Johns River Water Management District are monitoring algal blooms in the lower St. Johns River in Putnam, Clay and St. Johns counties, early signs the river could be in for a repeat of last summer's bloom that prompted health warnings.

District staff said some algal blooms are not harmful to people, but some species are associated with the production of toxic compounds.

Samples were collected Monday from Rice Creek at the railroad bridge, and water samples were taken from the St. Johns River at Racy Point, Eagle Point south of the Shands Bridge, and the center of the river in Palatka. The samples will be examined by algae experts to determine the algal species and concentration of any toxins. Results will be announced when they become available.

While the peak season for algae to proliferate is typically late summer to early fall, current dry conditions appear to have triggered an algal bloom. Algal blooms are caused by a combination of hot, overcast days, calm wind and excessive nutrients in the water, such as fertilizer runoff, stormwater runoff and wastewater.

Effluent from industrial and wastewater treatment plants is the largest contributor of nutrients in the lower St. Johns River, followed by agricultural and stormwater pollution. The upstream watersheds of the upper and middle St. Johns River also contribute significant sources of nitrogen and phosphorus to the lower St. Johns River south of Duval County. The District and local government and utility partners are working together to initiate new projects or expand current projects to reduce nutrient pollution and to meet and ultimately exceed state water quality standards, called total maximum daily loads.

The Legislature approved $10 million last week for the initiative for the next fiscal year, which begins Oct. 1. The district also has committed $17.5 million for lower basin initiatives next year.

Meantime, the district will collect water samples biweekly from several benchmark stations in the lower basin this summer and collect samples from scums staff observes in the field.

Harmful algal blooms can produce toxins, block sunlight from reaching aquatic plants, deplete dissolved oxygen, and compromise the survival of fish and other wildlife.

The district recommends using common sense and following World Health Organization guidelines, such as avoiding contact with visible algae, water with a strong greenish discoloration, and algal scums.

For more information about participating in water-related activities or about eating fish or seafood caught in an algal bloom, contact the local health department:

• Clay County Health Department, (904) 269-6341, Ext. 148
• Duval County Health Department, (904) 630-3251
• Putnam County Health Department, (386) 326-3267
• St. Johns County Health Department, (904) 823-2514, Ext. 105