by Max Marbut
Staff Writer
The extremely hot, dry weather in North Florida hasn’t created many “chamber of commerce days,” but it likely has prevented having another “Green Monster” algae bloom in the St. Johns River.
The conditions also may be contributing to North Florida’s manatee population migrating south later than usual this year.
That was the report delivered Wednesday to the City’s Waterways Commission by Quinton White, executive director of Jacksonville University’s Marine Science Research Institute.
“The lack of rainfall has caused a higher-than-normal level of salinity. That has probably prevented an algae bloom this year,” he said.
Lower than average rainfall also has reduced the amount of stormwater runoff into the river, further hindering an algae bloom so far, said White.
Sea water contains 35 parts per thousand of salt, while fresh water is 1. White said the salinity level of the river measured at JU is between 17-20 ppt, higher than average.
Last year’s algae bloom has had a long-term effect on the river’s ecology. White said the bloom combined with the fish kill has created an abundant number of crustaceans in the estuary and described this year’s river shrimping season as “one of the best ever.”
Water temperature also is affecting the migration pattern for area manatees.
White said at between 85-87 degrees F, the river is warmer than usual for this time of year. Manatees begin to leave the area for the winter when water temperatures fall, but even with the warm water, the manatee population already is decreasing.
“As the days get shorter, the manatees understand cool weather is coming and they head south,” White said.
The manatee population has been measured for years and this month, JU added a St. Johns River dolphin census to its agenda. The first count was taken Aug. 2 with more data scheduled to be gathered Aug. 15 and Aug. 30.
White said early numbers indicate almost 200 dolphins in the St. Johns River. The marine mammal census-takers are photographing the animals’ dorsal fins. Each fin is unique in terms of shape and markings, which can allow individuals to be tracked.
“Over the next several years, we’ll exchange that information with researchers up and down the East Coast,” said White.
Another issue discussed by the commission is the coexistence of anglers, shrimpers and boaters at the City’s docks at Metropolitan Park.
Capt. Jim Suber, the City’s dockmaster and consultant to marinas and waterways, said recently a shrimper identified himself to a boater as “the dockmaster” and instructed the boater to leave the area.
Recreational boater Charles Parks testified that “the issue started years ago,” about the time the City enacted an ordinance allowing fishing and netting from two of the docks at the park during daylight hours only.
Parks said most of the anglers and shrimpers are courteous, “but some are not.”
He cited instances when fishing lines and nets have become entangled in boat propellers when people fished at docks designated for docking.
Parks predicted that with the impending football season, conflicts may become more numerous and like last year, the Jacksonville Sheriff’s Office might be called to resolve differences between boaters and anglers.
“They were called several times. I called them twice myself,” said Parks.
Suber said he’s working with the mayor’s office to identify ways to improve the situation. One possibility is to increase the informational signage on the docks.
“Metropolitan Park is a popular spot for fishing. We’ll try to work out a solution for both sides,” he said.
The commission voted to approve and send to City Council an ordinance that would appropriate a $5,000 grant from the Florida Inland Navigation District to provide funding for litter prevention and education programs for the Keep America Beautiful affiliates.
The funds would be used to purchase T-shirts, gloves, trash bags and other supplies for about 1,000 local volunteers expected to participate in the Sept. 17 “International Coastal Cleanup.”
City Environmental Programs Coordinator Vivian Harrell said the supplies also will be used to clean up Duval County’s shoreline as part of a year-round initiative.
City Council is scheduled to vote on the ordinance (2011-447) as an emergency action because the deadline for grant purchases is Sept. 30.
The Waterways Commission’s next scheduled meeting is at 9:30 a.m. Sept. 14 in the Council Chamber at City Hall.
356-2466