First Coast
Red Tide at Fernandina Beach Today
The latest Florida Fish & Wildlife water samples near Fernandina, updated daily.
Current status
Thursday, August 6Respiratory irritation is possible along the beach, and shellfish harvesting may be closed.
Based on 17 water samples collected within 35 miles of Fernandina, the most recent on Aug 5.
Wind right now: SE at 7 mph — blowing onshore, which is what pushes a bloom and its irritation toward the beach.
Nearest samples
| Location | Distance | Sampled | Result |
|---|---|---|---|
| Fort Clinch (St. Marys Inlet) | 2.5 mi | Aug 2 | very low |
| St. Marys Inlet | 3 mi | Aug 3 | low |
| Tiger Creek; NE of (St. Marys River) | 3.3 mi | Aug 5 | not detected |
| Waterville Road; NW of (Pumpkin Hill Creek) | 9.1 mi | Aug 5 | not detected |
| Christopher Creek; SE of (Nassau River) | 9.7 mi | Aug 5 | not detected |
| Nassau Inlet | 10.8 mi | Aug 3 | not detected |
| Sawpit Creek; E of (Nassau Sound) | 10.9 mi | Aug 3 | very low |
| Sawpit Creek; E of (Nassau Sound) | 10.9 mi | Aug 3 | very low |
What red tide is
Red tide on Florida’s Gulf coast is a bloom of Karenia brevis, a single-celled alga that lives offshore year-round and occasionally multiplies into concentrations dense enough to discolour the water. It produces brevetoxins, which kill fish and — when wind and surf break the cells open — drift ashore as an aerosol that makes people cough. Blooms usually start 10 to 40 miles offshore and are carried inshore by currents and wind, which is why one beach can be miserable while the next one up the coast is fine.
Around Fernandina, a bloom matters for more than the beach: it can shut down the redfish and spotted seatrout bite for weeks, and dead fish along St. Marys Inlet & the Atlantic are usually the first sign that one has moved in.
What the levels mean
Florida Fish & Wildlife counts cells per litre in each water sample and sorts the result into five bands. These are the state’s own categories, not ours.
| Level | Concentration | What you’d notice |
|---|---|---|
| Not detected | under 1,000 cells/L | Background. Nothing to notice. |
| Very low | 1,000 – 10,000 | Possible respiratory irritation for the sensitive. |
| Low | 10,000 – 100,000 | Respiratory irritation; shellfish closures possible. |
| Medium | 100,000 – 1,000,000 | Irritation likely; fish kills possible. |
| High | over 1,000,000 | Irritation, discoloured water, fish kills. |
Checking the beach before you drive
Samples are collected every few days, not continuously, so the honest way to read this page is “here is what the water tested at recently.” Conditions can change in a day. Two things fill the gap: wind direction — an onshore breeze carries irritation to the beach while an offshore one holds it out — and other people. If a bloom is inshore, the local fishing groups know before any official map does.
Rule of thumb: if you get to the beach and start coughing within a few minutes, or the water looks the colour of weak tea with dead bait along the wrack line, that is red tide regardless of what the last sample said.
Red tide at Fernandina: common questions
- Is there red tide at Fernandina Beach right now?
- As of the most recent Florida Fish & Wildlife samples (Aug 5), red tide near Fernandina Beach is low. Respiratory irritation is possible along the beach, and shellfish harvesting may be closed.
- How often is red tide data for Fernandina updated?
- Florida Fish & Wildlife publishes the last eight days of water samples and refreshes the feed daily. This page reads that feed hourly, so it reflects the newest sample as soon as the state posts it. Sampling itself happens every few days, not continuously.
- Can you swim or fish at Fernandina during red tide?
- At low concentrations most people are fine, though anyone with asthma or a respiratory condition should be careful near the surf. At medium and high levels expect coughing on the beach and dead fish in the water. Fish caught alive in a bloom are generally considered safe to eat if filleted, but never eat dead or distressed fish, and do not harvest shellfish from closed areas.
- Why does one beach have red tide and the next one doesn't?
- Blooms are patchy and move with wind and current. A concentration sitting a few miles offshore can be pushed onto one stretch of St. Marys Inlet & the Atlantic by an onshore breeze while the beach around the corner stays clear, then reverse the next day when the wind turns.
Red tide near Fernandina
Sample data from the Florida Fish & Wildlife Research Institute, which publishes the last eight days of Karenia brevis sampling statewide and refreshes it daily. Salty Forecast reads that feed and shows the samples nearest you — we do not test water ourselves. For health guidance see the Florida Department of Health; for beach-by-beach reports from actual observers, see Mote Marine’s Beach Conditions Reporting System.