Bottlenose Dolphins Around St. Petersburg and Tampa Bay

The dolphins seen from St. Petersburg are common bottlenose dolphins, and NOAA Fisheries splits them into a Tampa Bay Stock inside the bay, a St. Joseph Sound/Clearwater Harbor Stock to the north and a Gulf Eastern Coastal Stock offshore.

NOAA's stock assessment for the northern Gulf's bays, sounds and estuaries treats each enclosed or semi-enclosed water body as a separate stock and gives Tampa Bay label number 24 and St. Joseph Sound/Clearwater Harbor label number 23 in its stock table (NOAA Fisheries bay, sound and estuary report). The idea of resident bay stocks comes from field work begun in the 1970s in Sarasota Bay, and the report says that in Florida long-term residency has been reported from Tampa Bay, citing work as early as Wells (1986). The report describes that residency as long-term, meaning year-round and multi-year.

Inside Tampa Bay the picture is finer than one stock. The same report says Urian et al. (2009) described five discrete communities in Tampa Bay, including the adjacent Sarasota Bay community, that differed in their social interactions and ranging patterns, even though the open bay has no physical barrier to keep them apart (NOAA Fisheries). Urian et al. (2009) recommended that management account for fine-scale structure within current stock designations, and the report concludes it is plausible that some estuarine stocks, particularly those in larger bays, comprise multiple demographically independent populations.

Beyond the beaches of Pinellas County, dolphins belong to the Gulf of Mexico Eastern Coastal Stock, whose area runs from 84 degrees west longitude to Key West in waters from the shore out to the 20-m isobath (NOAA Eastern Coastal Stock report). NOAA calls that 20-m line a management boundary rather than an ecological one. The common bottlenose dolphin is not listed under the Endangered Species Act, and the Eastern Coastal report says that stock is not considered strategic under the Marine Mammal Protection Act.

NOAA's current stock table lists the Tampa Bay Stock's size as unknown, while the Eastern Coastal Stock off the Pinellas coast has a best estimate of 16,407 dolphins from 2017 and 2018 aerial surveys.

The figures below are taken as printed from the two NOAA reports that cover the water around St. Petersburg. UNK means unknown and UND means undetermined; HCMSI is the minimum annual count of human-caused mortality and serious injury for 2015 to 2019.

Sources for the St. Petersburg area table: the bay, sound and estuary report for the first three rows and the Eastern Coastal report for the last. The Eastern Coastal estimate is an inverse-variance weighted average of a summer count of 11,482 and a fall count of 21,386, and its PBR (potential biological removal) of 114 comes from the minimum estimate of 14,199. The report puts the stock's minimum total mean annual human-caused mortality and serious injury for 2015 to 2019 at 9.2, including a shrimp trawl mean of 7.6, and calls the full total unknown because the stock interacts with unobserved fisheries.

The Tampa Bay row is the gap that matters for St. Petersburg. NOAA says population estimates for most bay stocks are more than eight years old, so all but three are now treated as unknown, and NMFS considers Tampa Bay and most other bay stocks strategic because their sizes are unknown but likely small, so relatively few deaths could exceed PBR (NOAA Fisheries). The only bay-wide count in these NOAA documents is three decades old: a NOAA technical memorandum found that between 437 and 728 dolphins used its 852 square kilometer Tampa Bay study area in September and October during 1988 to 1993 (NOAA Technical Memorandum NMFS-SEFSC-385).

Two dating details are worth knowing before quoting these numbers for Tampa Bay. The bay, sound and estuary report carries a May 2021 date and a note that it has not been revised, and it counts 32 bay stocks after moving Florida Bay into the Gulf list (NOAA Fisheries), while NOAA's report index still describes 31 bay, sound and estuary stocks and labels the Eastern Coastal report 2021 although the PDF itself is dated May 2022 (NOAA stock report index). NOAA species pages now say Gulf of America; the stock reports still say Gulf of Mexico.

Tampa Bay dolphins use Boca Ciega Bay, the Sunshine Skyway reach of lower Tampa Bay, the St. Petersburg shoreline and Old Tampa Bay, with the bay mouth acting as a mixing area.

The 1988 to 1993 NOAA study mapped seven survey regions (NOAA technical memorandum). Region 4, Boca Ciega Bay, is a complex of barrier islands, shallow seagrass meadows and channels. Region 3 runs from the Sunshine Skyway Bridge to just west of Egmont Key and holds the main shipping channel. Region 5, northeast of the Skyway, is the largest, with the mostly undeveloped southeastern shore on one side and the highly developed St. Petersburg shoreline to the northwest. Old Tampa Bay, Region 6, is an open bay crossed by three bridge and causeway systems.

Movement is seasonal and social. NOAA's bay report says dolphins from several areas were documented at the mouth of Tampa Bay and that fall and winter increases in abundance have been noted for Tampa Bay (NOAA Fisheries). Off the beaches, photo-identification surveys of coastal waters off Tampa Bay, Sarasota Bay and Lemon Bay found inshore dolphins favoring waters near passes and Gulf dolphins ranging farther out; in winter the Gulf groups decreased and the inshore groups increased (NOAA Eastern Coastal report).

Feeding habits include the urban edge. NOAA notes that bottlenose dolphins may trap schools of fish against sand bars and seawalls (NOAA species page), and the Eckerd College Dolphin Project describes resident seawall feeders in its lower Tampa Bay study area that herd schools of fish against seawalls and take turns darting in (Eckerd College). NOAA's species page lists adults at 6 to 13 feet long and 300 to 1,400 pounds, with a lifespan of 40 to 60 years.

Federal rules at 50 CFR 216.3 count feeding or attempting to feed a wild marine mammal as a take, and NOAA asks boaters around St. Petersburg to stay at least 50 yards from dolphins.

For the dolphins of Tampa Bay, the definitions section of the Marine Mammal Protection Act regulations says take includes the negligent or intentional operation of a vessel that results in disturbing or molesting a marine mammal, and feeding or attempting to feed a marine mammal in the wild (eCFR, 50 CFR 216.3). Feeding is defined as offering, giving or attempting to give food or non-food items to marine mammals in the wild, and it includes operating a vessel or other platform from which feeding is done. The feeding definition leaves out the routine discard of bycatch during fishing operations. Level B harassment is any act of pursuit, torment or annoyance that could disrupt behavior such as breathing, nursing, feeding or sheltering.

NOAA's viewing guidance turns that into distances for boaters on Tampa Bay and Boca Ciega Bay (NOAA viewing guidelines). The guidance sets a distance of at least 50 yards from dolphins, half a football field, when viewing from watercraft, and notes that in some locations the minimum may be 100 yards. It limits time with any individual or group to 30 minutes or less, rules out chasing, encircling or leapfrogging animals or trapping them between boats and the shore, calls for no-wake speed near them and advises against approaching when calves are present. The same page says not to swim with, pet or touch marine mammals in the wild.

This is a live issue in Tampa Bay, not a hypothetical one. NOAA's stock report documents provisioning of four dolphins within the Tampa Bay Stock area during 2019 while the dolphins were swimming in a local canal, and notes emerging questions about links between provisioning and depredation of recreational fishing gear (NOAA Fisheries).

NOAA's 2015 to 2019 records list repeated gear entanglement injuries among Tampa Bay dolphins, and NOAA puts the Tampa Bay Stock's minimum human-caused figure at 3.0 a year, against 0.6 for St. Joseph Sound/Clearwater Harbor and 0.2 for Sarasota Bay/Little Sarasota Bay.

The report's table of at-sea observations of dolphins entangled in fishing gear lists Tampa Bay against nine serious injury determinations recorded solely in Tampa Bay from 2015 to 2019, plus one more listed as Tampa Bay or Eastern Coastal (NOAA bay, sound and estuary report). That table covers dolphins seen entangled in hook and line, crab trap or unidentified gear or showing vessel-strike injuries. For hook and line gear, NOAA notes it usually cannot tell whether the gear came from a charter boat, headboat or recreational angler, and that there is no systematic observer program for it, so the documented cases are a minimum count. Across the northern Gulf's bays, 527 common bottlenose dolphins stranded during 2015 to 2019, with evidence of human interaction for 102 of them.

Other pressures named on NOAA's species page include biotoxins, chemical contaminants, habitat alteration, illegal feeding and harassment, ocean noise and vessel strikes (NOAA Fisheries). The Eastern Coastal report adds that some areas such as Tampa Bay are highly industrialized (NOAA Fisheries); the 1988 to 1993 NOAA study described Hillsborough Bay, at the head of Tampa Bay, as the most extensively altered part of the bay (NOAA technical memorandum).

A stranded, entangled or injured dolphin in St. Petersburg waters is reported to the NOAA Southeast Marine Mammal Stranding Hotline at 877-942-5343 or the FWC Wildlife Alert Hotline at 888-404-3922.

NOAA's reporting directory lists the Southeast hotline as (877) WHALE-HELP (877-942-5343) and, for Florida, the FWC Wildlife Alert Hotline at (888) 404-FWCC (888-404-3922) (NOAA Fisheries report page). The same directory names the Florida stranding network members closest to St. Petersburg: Clearwater Marine Aquarium in Clearwater, the Florida Aquarium in Tampa and the FWC FWRI Marine Mammal Pathobiology Laboratory in St. Petersburg. Mote Marine Laboratory in Sarasota is listed for the coast to the south.

The federal definition of take covers the restraint or detention of a marine mammal, no matter how temporary, and the collection of dead animals or parts of them (eCFR, 50 CFR 216.3). The 2015 to 2019 Tampa Bay injury list in the bay report comes from at-sea observations, counted in addition to the animals in the stranding database (NOAA Fisheries). Last verified: October 18, 2026, against the two NOAA Fisheries stock assessment reports, the eCFR text of 50 CFR 216.3 and the NOAA stranding directory.

The Eckerd College Dolphin Project in St. Petersburg has studied Tampa Bay dolphins since 1993, working mainly in lower Tampa Bay, Boca Ciega Bay and coastal Gulf waters.

According to the college, the project was started by Dr. John Reynolds and is led by Dr. Shannon Gowans and Dr. Peter Simard, with students working year-round (Eckerd College Dolphin Project). Its photographs are taken under NMFS LOC No. 15512. Dorsal fin photographs are matched with DARWIN, software developed by the Eckerd College Computer Science department, and autonomous acoustic recorders are serviced around the study area.

Two Eckerd studies speak directly to St. Petersburg waters. One compared Tampa Bay sighting rates before and after the April 20, 2010 Deepwater Horizon spill, which the college places about 350 miles (570 kilometers) WNW of Tampa Bay, and found sighting rates rose after the spill without being able to say the spill caused it. Another found that bottlenose dolphins raised the frequency of their whistles when ambient noise, including recreational boat noise, was higher. Federal stock science for the bay rests on earlier NOAA work: the 1988 to 1993 Tampa Bay monitoring was a NOAA Southeast Fisheries Science Center technical memorandum (NOAA), and NOAA's report index lists the Eastern Coastal Stock's most recent report as 2021 (NOAA stock report index).