Dolphins in Jacksonville: The St. Johns River Population, Its Risks and How to Watch Them

The University of North Florida's Dolphin Research Program says yes, calling the St. Johns River significant year round habitat for a resident dolphin community (UNF Dolphin Research Program).

UNF's weekly surveys find dolphins consistently along its whole route from the Mayport inlet to downtown Jacksonville, about 40 km up the river.

That finding departs from the older studies NOAA Fisheries still summarizes. The federal stock assessment cites a 2003 study that found dolphin abundance in the Jacksonville estuaries oscillating through the year, with low counts in January and December and peak numbers once water warmed above 16 C, and it describes 1994 to 1997 photo identification work in which dolphins in the area south of the St. Johns River returned each summer rather than staying year round (NOAA Fisheries stock assessment). UNF itself writes that its result runs contrary to previous reports from the 1990s. The two sources describe different survey periods and neither settles the other.

This page covers the Jacksonville dolphin population as the federal government manages it, the stranding record, the rules on feeding and approaching dolphins, and where to watch and report. The manatees, sea turtles and right whale guides cover the other protected animals in Jacksonville waters. Last verified: October 18, 2026, against the NOAA Fisheries Jacksonville Estuarine System stock assessment of May 2023, NOAA's bottlenose dolphin species page and stranding contact list, two University of North Florida Dolphin Research Program pages, and the Timucuan Preserve mammals and hours pages.

NOAA Fisheries manages Jacksonville's estuarine dolphins as the Jacksonville Estuarine System Stock, running from the Florida and Georgia line at Cumberland Sound south to Jacksonville Beach, and it lists the stock's current size as unknown (NOAA Fisheries stock assessment).

The stock area is a set of brackish rivers, the St. Mary's, Amelia, Nassau, Fort George and St. Johns, plus tidal marshes averaging 2 m deep and the Intracoastal Waterway; the assessment describes the St. Johns as a deep, swift river with heavy boat and shipping traffic (NOAA Fisheries). Studies from December 1994 to December 1997 found separate communities north and south of the St. Johns River and a mobile coastal group, with the northern dolphins the most isolated and showing strong year round site fidelity. A 2020 study recommended splitting the area north of the St. Johns into its own stock and suggested extending the southern boundary to the St. Augustine inlet.

The only Jacksonville population figure is old. Photo identification from 1994 to 1997 gave an estimate of 412 residents, which NOAA calls an overestimate because it included seasonal and transient animals; 122 dolphins were resighted at least 10 times, 33 mostly in the northern area and 89 in the southern area (NOAA Fisheries). With no current minimum estimate, NOAA cannot calculate a Potential Biological Removal level for the stock.

The two main sources also name the animal differently. The May 2023 assessment uses Tursiops truncatus truncatus, the common bottlenose dolphin (NOAA Fisheries), while UNF calls the St. Johns River dolphins Atlantic bottlenose dolphins, Tursiops erebennus (UNF Dolphin Research Program).

NOAA Fisheries lists the Jacksonville Estuarine System Stock as strategic under the Marine Mammal Protection Act because its documented deaths and serious injuries are incomplete and biased low and likely exceed its Potential Biological Removal level once corrected for unrecovered carcasses (NOAA Fisheries stock assessment).

Bottlenose dolphins in the western North Atlantic are not listed under the Endangered Species Act, the same assessment notes. For 2016 to 2020 it puts the minimum mean annual human caused mortality and serious injury for the Jacksonville stock at 2.0 animals a year, all with evidence of fishery interactions in crab trap and pot gear or hook and line gear (NOAA Fisheries). Three commercial fisheries interact or could interact with the stock: the stone crab and Atlantic blue crab trap and pot fisheries and the commercial passenger fishing vessel hook and line fishery.

The gear record for those five years lists eight entanglements in trap and pot gear in the Jacksonville area and five hook and line cases in the stranding data, plus two live dolphins seen entangled in hook and line gear at sea (NOAA Fisheries). UNF says several St. Johns River dolphins are severely entangled in fishing gear and lines each year and that its team helps agencies identify and rescue them (UNF Dolphin Research Program).

NOAA Fisheries counts 55 bottlenose dolphin strandings in the Jacksonville Estuarine System Stock area from 2016 to 2020, between 8 and 15 a year, with evidence of human interaction in 19 of them (NOAA Fisheries stock assessment).

For the other 36 Jacksonville area strandings it could not be determined whether there was human interaction. Thirteen of the human interaction cases were trap, pot or hook and line entanglements, and two animals showed evidence of a vessel strike, one of them also entangled (NOAA Fisheries). NOAA stresses that evidence of human interaction does not necessarily mean it caused the stranding or death. South of the stock boundary, in estuaries no stock assessment covers, another 29 dolphins stranded in the same five years.

An unusual mortality event was declared for the St. Johns River area in 2010, and NOAA Fisheries lists its cause as undetermined (NOAA Fisheries).

The NOAA Fisheries assessment says the event covered the St. Johns River area from May to September 2010 and included 14 strandings assigned to the Jacksonville stock plus four in estuaries to the south that no stock assessment covers (NOAA Fisheries stock assessment). UNF dates its own Dolphin Research Program to March 2011 and describes it as an effort to fill the gap in knowledge about the river's dolphins (UNF Dolphin Research Program).

A second, coastwide unusual mortality event from 2013 to 2015 also reached the river. NOAA says most of its strandings came from ocean beaches rather than estuaries, but several confirmed cases were recovered inside the Jacksonville stock area (NOAA Fisheries).

No: feeding or trying to feed wild bottlenose dolphins in Jacksonville or anywhere else is illegal under the regulations that implement the Marine Mammal Protection Act, and harassment is illegal under the act itself (NOAA Fisheries).

For dolphins in Jacksonville waters as anywhere in the United States, NOAA Fisheries defines harassment as any act of pursuit, torment or annoyance that has the potential to injure a dolphin or disrupt its behavior, and the regulations also bar negligent or intentional operation of a vessel or aircraft that disturbs or molests a marine mammal (NOAA Fisheries). The agency says fed dolphins learn to beg and to take bait and catch off fishing gear, which leaves them more exposed to vessel strikes and entanglement. Its viewing guideline is to stay at least 50 yards away and watch for 30 minutes or less. Violations go to the NOAA Fisheries Enforcement Hotline at (800) 853-1964, staffed 24 hours a day.

For boaters on the St. Johns River, UNF adds two practical points: stay at least 50 yards from dolphins and put the engine in neutral when they are near, and do not feed, touch or swim with them (UNF Dolphin Research Program).

The Timucuan Ecological and Historic Preserve names bottlenose dolphins among its frequently observed mammals and notes they are frequently spotted from the Fort Caroline observation platform (NPS Timucuan mammals).

The Fort Caroline National Memorial grounds are open from 9:00 a.m. to 5:00 p.m., Wednesday through Sunday, and close on Thanksgiving, Christmas Day and New Year's Day (NPS Timucuan hours). UNF's own survey route, from the Mayport inlet to downtown Jacksonville, is where its team has identified more than 520 individual dolphins (UNF Dolphin Research Program).

A stranded, injured or dead dolphin in Jacksonville goes to the FWC Wildlife Alert Hotline at (888) 404-FWCC (888-404-3922) or the NOAA Fisheries Southeast Marine Mammal Stranding Hotline at (877) WHALE-HELP (877-942-5343), and NOAA asks people and pets to stay at least 50 yards (150 feet) back (NOAA Fisheries stranding contacts). UNF adds that the animal should not be pushed back into the water and that, if possible, the caller should wait with it until a trained responder calls back (UNF).