On Friday, February 23, 2024, NOAA Fisheries received a report of a 15-foot female white shark that washed up on the shores of Navarre Beach, Florida. Local partners quickly responded to the event and monitored the shark. The NOAA Fisheries Office of Law Enforcement then transported it to the NOAA Southeast Fisheries Science Center facility in Panama City, Florida. There, our scientists conducted a necropsy, or animal autopsy. While the team was not immediately able to determine the cause of death, they collected extremely rare samples from this enormous elasmobranch.
A “Great” Amount of White Shark Information
NOAA Fisheries researchers Michelle Passerotti, Heather Moncrief-Cox, and John Carlson led a team of eight biologists in conducting the necropsy over the weekend. They spent 9 hours collecting precise measurements, recording detailed notes, and dissecting the animal to gain valuable samples and information about the shark.
“While white sharks are more common in the Gulf of Mexico than most people realize, they are rarely encountered by our survey programs.” said Heather Moncrief-Cox, a NOAA Fisheries affiliate with the Cooperative Institute for Marine and Atmospheric Science. “In fact, this is only the fourth white shark that the Southeast Fisheries Science Center Shark Population Assessment Group has been able to collect biological samples from, and the first that we’ve had the opportunity to perform such an extensive necropsy on.”
The white shark is one of the most well-studied shark species in the world. They gather in key feeding areas along coastlines throughout the world, which allows researchers to study them closely and predictably. However, most of these studies occur with live animals. Some samples—like vertebrae for ageing, stomach contents for diet studies, or reproductive measurements—can only be collected from a dead specimen. Opportunities to study dead sharks are incredibly important for science.
Information Collected from the Necropsy
Surprising Discoveries
One of the most fascinating discoveries from this dissection was the fact that the 15-foot female, though estimated to be close to 30 years old, was not reproductively mature. Initial speculations that the shark was pregnant were not accurate. This particular species can live to be near 80 years old, and females are thought to mature between 30–35 years of age. This finding was quite a surprise for the biologists.
A circle hook was present in the corner of the shark’s jaw, indicating that the shark was recently caught and released.
“I was amazed that she was still immature. Previously, we thought most females could reproduce at this size. This shows just how little we know about these animals,” said John Carlson, a NOAA Fisheries research biologist who assisted with the necropsy.
Other Information
Size
The shark was slightly more than 15 feet long (420 centimeters fork length, 460 centimeters total length) and more than 8 feet in girth. These data allow us to estimate the age of the animal and add to our knowledge of growth rates over the lifespan of this species.
Sex
The shark was a female. The size and condition of her reproductive organs indicate she was not yet able to reproduce, but may have been ready in the next 1 to 2 years.
Condition
Its body condition was considered normal and healthy; there were no indications of starvation, disease, or trauma.
Diet
The stomach was retained for its contents to be analyzed at a later date.
Liver
The shark’s liver was considered to be of healthy size and condition; it weighed more than 400 pounds. This indicates the shark was eating well and had adequate energy reserves.
Other samples taken include:
- Muscle and liver biopsies: used in toxicology screenings
- Eye lenses: used to study feeding and movement ecology
- Vertebrae: used to estimate the age of the shark
- Blood: used to estimate levels of potential contaminants and toxins
- Fin clips: used for DNA analysis
Additional tissues from all major organs were sent for pathology to further screen for potential causes of mortality. The team also took additional samples to support ongoing research projects led by academic partners.
“Any opportunity to collect biological samples and data from a white shark is incredibly important for understanding their life history,” said Michelle Passerotti, fish biologist in the Northeast Fisheries Science Center Apex Predators Program. “While strandings like this one are fairly rare even in the northern Atlantic where they have more resident populations, this event is extremely rare in the Gulf of Mexico and provides a treasure trove of information for this species.”
We study the biology of white sharks, monitor their populations and manage fisheries that may incidentally catch them. However, there is still much we don't know about this species. Many basic questions about white shark abundance, life history, habitats, and movements remain unanswered. Data from necropsy may be helpful for getting some answers.
White Shark Status and Protection
Despite their fearsome reputation, white sharks (like many other shark species) take a long time to mature and have slow reproductive and growth rates. This makes their population vulnerable to declines from human impacts. Due to these natural vulnerabilities, the white shark is one of the most widely protected sharks globally.
The stock status for white shark populations in U.S. waters is unknown. Research by NOAA Fisheries scientists indicates that abundance trends have been increasing in the Atlantic since protections were first implemented in the 1990s. The sharks are also known to inhabit the Gulf of Mexico.
There have been at least two recent sightings of white sharks in the northern Gulf of Mexico so far this year, and their presence is not uncommon during this time of the year. There is no increased level of danger to the public.
Responsible Shark Fishing Practices
The white shark is a prohibited species (no retention allowed) in all U.S. waters and fisheries. There are no commercial fisheries for white sharks, but they are occasionally caught as bycatch. In federal waters of the Atlantic (including the Gulf of Mexico), the white shark is managed under the 2006 Consolidated Atlantic Highly Migratory Species Fishery Management Plan. The white shark is also protected internationally under CITES Appendix II, CMS Appendix II, UNCLOS, and other international regional fisheries management organizations. State fishing regulations also apply in waters of state jurisdiction.
A federal fishing permit is required to fish for sharks in federal waters. These permits, issued by NOAA Fisheries, help us communicate and enforce regulations and monitor how many sharks are caught. Federal regulations require the use of non-offset, non-stainless steel circle hooks (except when fishing with flies or artificial lures) when fishing for sharks in federal waters of the Atlantic (including Gulf of Mexico and Caribbean Sea). This increases the chance of hooking a shark in the jaw instead of the gut, reducing injury to the shark’s internal organs. A shark that is hooked in the jaw is also easier and safer to dehook.
How to Report a Shark
If you see a sick, injured, or deceased shark along the Gulf of Mexico Coast, please report it to the NOAA Southeast Fisheries Science Center by calling (850) 234-6541. When reporting, please include:
- Date and time
- Location (GPS, closest street address, etc.)
- Species (if known)
- Approximate length
- Condition (alive, freshly dead with little decay, dead with some decay, dead very decayed)
- Tag number (if present and is safely accessible)
Consider collecting photos to document the animal’s condition at the time of sighting to share with our scientists. This information can help us better understand and effectively manage shark populations.
