Manatee waters clear of red tide

Rainbow - Cindy Lane | Sun

ANNA MARIA ISLAND – No red tide is predicted in Anna Maria Island waters through Monday, Jan. 28, and area waters remained clear of red tide last week, according to today’s Florida Fish and Wildlife Conservation Commission (FWC) report.

NOAA predicts low to very low red tide-related respiratory irritation in Manatee County through Monday.

No red tide was found in water samples at the Rod & Reel Pier in Anna Maria, the Longboat Pass boat ramp in Bradenton Beach or Palma Sola Bay as of Jan. 22, according to the FWC. However, three red tide-related fish kills were reported in Manatee County over the past week, one at the Anna Maria City Pier.

Respiratory irritation was reported on Jan. 17 and Jan. 19-20 at Coquina Beach in Bradenton Beach and Jan. 20-21 and Jan. 23 at Manatee Beach in Holmes Beach, according to the FWC.

Blooms of Florida red tide can be patchy, with varying concentrations of the toxin it produces, causing effects to be noticeable on one beach but not on a nearby beach.

The bloom, which is now affecting Collier County to the south, began in Southwest Florida in October 2017 and arrived in Anna Maria Island waters on Aug. 3.

Wildlife impacts

Since the bloom began in 2017, red tide has caused 589 sea turtle deaths, according to the FWC.

Of the 824 manatees that died in Florida waters in 2018, 132 of them were caused by red tide, including 10 from Manatee County, with six of those discovered around Anna Maria Island and Longboat Key, the FWC reports. An additional 79 manatee deaths are suspected to have been caused by red tide, for a total of 211 probable red tide deaths, more than from watercraft (121 deaths) last year.

As of Dec. 20, 2018, 127 dolphins had died from red tide in Florida waters, according to NOAA, which stopped tracking dolphin mortality during the federal government shutdown that was suspended today.

Causes

Florida red tide, or Karenia brevis, is a type of microalgae that emits a neurotoxin when it blooms. Deadly to marine life, red tide also can make shellfish unfit to eat and can cause respiratory irritation in people.

Scientists say that salinity, currents, temperature and light play a part in the formation of red tide blooms, in addition to:

  • nutrient runoff from Florida’s natural phosphate deposits
  • nutrients from the Loop Current, which brings Caribbean seawater to Florida’s west coast
  • natural and man-made nutrients that travel down the Mississippi River to the Gulf of Mexico
  • nutrients from iron-rich Saharan dust blown across the Atlantic Ocean to Florida’s waters
  • nutrients including nitrogen and phosphorus from fertilizers and animal waste.