Inside Guy Harvey's 23-Year Stingray Census

Stingray Census 2025 Recap! Stingray City Sandbar is a special place located in North Sound, Grand Cayman where southern stingrays, Dasyatis America, interact with visitors from around the world on their own volition.

The Guy Harvey Foundation and Nova Southeastern University have been studying these animals in partnership with the Department of Environment since 2002. Each animal processed during the stingray census is identified with a unique passive integrative transponder (PIT), measured and have any unique features documented (ie. Sex, scars, markings, injuries etc) before being returned carefully back into the water. Small tissues samples are collected for use in genetic analysis and help differentiate which animals have already been processed. These samples, not much bigger than a 25-cent piece, will grow back in a few months.

Part of the team at the 23-year Stingray Census tagging and taking samples of one of the Stingrays.

This past weekend a total of 92 stingrays were processed, only 4 of which were males. Eight animals were newly tagged, adding to the over 600 animals recorded in this 23 year study. Many females were suspected to be pregnant but with the absence of an ultrasound could not be verified. The largest animal measured was a female at 128cm (4ft) in width and the smallest, an immature new male at 39cm (1ft). Last summer the census was abruptly cut short due to Hurricane Beryl. The most stingrays ever recorded in a census was 115.

Among the 24 incredible volunteers, we had members from St. Mathew’s Veterinary school, Department of Environment and NSU. Shelby Pawlinsky, an NSU masters student working under Dr. Mahmood Shivji at the Guy Harvey Research Institute is currently studying the relatedness between the animals at this site using samples collected! We look forward to sharing more following the completion of the study. GHF is grateful to everyone who participated, including Epic Divers who have supported the study with their crew and dive boat for several years.

Students from the Guy Harvey Research Institute participate each year on the Stingray census at Grand Cayman

Tour boat operators are also important stakeholders in this study. The GHF is grateful to all those who have sent in reports on the water during and outside the stingrays census efforts and assist with providing unprocessed rays should they come across them during their tours. The Epic Divers dive platform provides space for guests to also observe the operation of the stingray survey and encourages tour boat operators to continue to take advantage of this opportunity; meeting scientists, learn the latest news, ask questions, inform their guests and see what’s involved from a stable platform.

Should you visit the sandbar when the next stingray census is being conducted, look out for the colored flags that indicate the number of animals processed; RED = 10 stingrays, BLUE = 5 stingrays, WHITE = 1 stingray. The census is conducted biannually to compare seasonal differences.

GHF will continue to provide resources to conducting this study. Donations to the Guy Harvey Foundation can support the cost of operations and ongoing analysis. Visit www.guyharveyfoundation.org to learn more and make a contribution! 

Guy Harvey, Jessica Harvey and the team at the 23-year Stingray Census