Bottlenose Dolphins of the Sebastian Lagoon

Yes: the state lists the Atlantic bottlenose dolphin among the mammals of the aquatic preserve that covers this stretch of the Indian River Lagoon (Florida DEP), and FAU reports that lagoon dolphins keep to home areas (FAU).

That preserve, the Indian River-Malabar to Vero Beach Aquatic Preserve, spans 28,000 acres in Brevard and Indian River counties and was established in 1970; FDEP names the Atlantic bottlenose dolphin and the West Indian manatee as its two mammals (FDEP). FAU Harbor Branch Oceanographic Institute, which began its dolphin work in 1996 with a National Marine Fisheries Service authorized project to photo-identify and catalog every bottlenose dolphin in the lagoon (FAU Harbor Branch), now counts more than 400 identified individuals in its database from Sebastian to Jupiter Inlet (FAU, September 2024).

Lagoon dolphins, including those in the Indian River Lagoon off Sebastian, mostly stay put. FAU reports that lagoon dolphins keep to certain areas, do not usually travel more than 30 miles from home, and form six communities along the lagoon (FAU). The 2016 to 2017 lagoon wide survey estimated that transients made up only 0.06 of the marked population in winter and 0.07 in fall, a low rate its authors say supports a resident lagoon stock (PLOS ONE, 2021).

The most rigorous count put the Indian River Lagoon population at a mean of 1,032 dolphins in 2016 and 2017, ranging from 981 in winter to 1,078 in summer (PLOS ONE, 2021).

Hubbs-SeaWorld Research Institute scientists and collaborators ran that survey with 11 to 13 vessels following a 470 mile zig zag path that covered nearly all of the Indian River Lagoon, running 135 surveys and analyzing over 150,000 images (Hubbs-SeaWorld Research Institute). The published study breaks the estimate down by season.

A different number circulates locally. FAU Harbor Branch wrote in September 2024 that about 2,000 dolphins live in the lagoon, which it describes as a 156-mile waterway (FAU). FAU cites no survey behind that figure; the measured estimate remains the 2016 to 2017 one, which is now nearly a decade old. The study splits the Indian River into a northern sub-basin, north of the Eau Gallie Causeway, and a southern Indian River sub-basin that includes three of the lagoon's four inlets, the sub-basin that takes in Sebastian (PLOS ONE).

FDEP lists the Main Street Boat Ramp, Sebastian Inlet State Park, Dale Wimbrow Park and Jorgenson's Landing among the boat ramps and launches that give access to the preserve, which lists wildlife viewing among its activities (Florida DEP).

The research record backs the Sebastian end of the lagoon as dolphin water. From July 1996 to October 2001, FAU Harbor Branch ran 190 boat-based photo-identification surveys in the lagoon, with most of the effort between 1998 and 2001 in a primary study area from Sebastian Inlet south to Fort Pierce Inlet; of 336 dolphins identified, 149 were found in that stretch (Mazzoil and others, 2005).

Individual dolphins have known haunts. FAU profiled a male it calls Striker, or STKR, in August 2026, describing him as frequently sighted between Sebastian Inlet and Round Island Beach Park in Vero Beach (FAU, August 2026). Striker carries permanent scars from a boat strike that happened before the team began tracking him, which is why FAU used his profile to ask boaters to obey speed restrictions on the lagoon.

Other launch points FDEP lists for the same preserve include the Wabasso Causeway boat ramp, MacWilliams Park and Christenson's Landing (FDEP). FDEP notes visitation depends on local regulations and lists boating, fishing, kayaking, snorkeling, wildlife viewing and nature photography among the activities on this water.

NOAA Fisheries asks boaters and paddlers off Sebastian to watch dolphins from at least 50 yards and for no more than 30 minutes, and feeding them is illegal under the Marine Mammal Protection Act regulations (NOAA Fisheries).

NOAA explains why the feeding ban matters: dolphins fed by people lose their wariness and learn to link people with food, which puts them at risk (NOAA). FAU gives the same advice for the lagoon at Sebastian, adding that anglers should avoid casting lines toward dolphins, because the more comfortable dolphins become around boats and fishing activity, the higher their risk of injury (FAU Harbor Branch).

A stranded, entangled or injured dolphin on the Sebastian shoreline is reported to the FWC hotline at (888) 404-3922, the number FAU gives for any marine mammal in distress (FAU). FAU Harbor Branch's Marine Mammal Stranding and Population Assessment team is on call 24 hours a day, seven days a week, and FAU says the rescue team has helped save over 300 dolphins and whales (FAU).

NOAA Fisheries lists three unusual mortality events for Indian River Lagoon bottlenose dolphins: about 30 animals in 2001, 48 in 2008 and 79 in 2013 (NOAA Fisheries).

NOAA lists the 2001 event from May 1 to October 31, 2001, with an undetermined cause, the 2008 event from May 2 to September 4, 2008, with 48 dolphins and an undetermined cause, and the 2013 event from January 9 to December 31, 2013, with 79 dolphins and ecological factors as the cause (NOAA). The PLOS ONE study puts at least 77 deaths in the 2013 event at about 7.5 percent of the lagoon population, and notes that the Banana River and northern Indian River, where tidal flushing is poor, were the common epicenter of past events (PLOS ONE). Both lie north of Sebastian, and the study rates their water quality below that of most of the southern Indian River.

Because of those losses, Indian River Lagoon dolphins are listed as a strategic stock: managers judge that human-caused deaths likely exceed the Potential Biological Removal level, the most non-natural deaths the stock can absorb each year (PLOS ONE). NOAA lists illegal feeding and harassment, vessel strikes and fishing gear entanglement among the threats to the species (NOAA Fisheries), the same threats behind the scars FAU documents on lagoon dolphins such as Striker.

Shoreline photos taken in Sebastian can go to FAU Harbor Branch's Dolphin Spotter program, which matches fin pictures from the public against its catalog of lagoon dolphins (FAU Harbor Branch).

For a dolphin photographed off Sebastian, the dorsal fin is the key: each fin carries its own set of nicks, notches and scars, so a clear fin photo with the time and place can identify that individual (FAU). FAU says Dolphin Spotter photos are useful because they come from canals and marinas outside the regular survey zones, and that by September 2024 spotters had submitted 443 sightings, with Dolphin Spotter sightings matched to 32 dolphins in the Harbor Branch database.

The professional surveys of the Indian River Lagoon off Sebastian continue alongside the volunteers. A 2019 FAU thesis combined Harbor Branch monthly relocations of photo-identified dolphins from 2003 to 2015 with fish and environmental samples collected monthly by the FWC Fisheries-Independent Monitoring program to map where lagoon dolphins concentrate by wet and dry season (FAU thesis). FAU states that its Striker tracking work is conducted under NOAA NMFS permit 29340 (FAU).