Feeding Stingrays Makes For Lazy, Fat Stingrays

Is anyone surprised by these findings? Dr. Bradley Wetherbee, a University of Rhode Island professor, has studied tourist activities in Stingray City Sandbar in Grand Cayman since 2002 and has concluded that human feeding and habituation is responsible for the disruption of natural stingray behaviors and an increase in the size of the female population in stingrays.

In other words, lazy, fat stingrays.

"From an evolutionary point of view, for millions of years these stingrays have been nocturnal," Wetherbee said. "Tourists start feeding them during the day and they reverse their behavior. They became very active during the day, or diurnal, which they never were before, and now they sleep all night."

Wetherbee explained that in the wild, stingrays are bottom-feeders, and do not typically eat non-natural prey items, such as squid, which many tourists have been feeding them.

Wetherbee's most recent findings further corroborate previous research demonstrating that supplemental feeding changes the activity patterns, feeding habits and reproduction of stingrays. In 2006, then graduate student Mark Corcoran at Nova Southeastern University in Florida tagged and tracked more than 150 stingrays, comparing those that frequented Grand Cayman's Stingray City with unfed wild rays from other habitats.

They found that the fed rays remained at the Sandbar during the day, ranged around a bit at night and then returned to the Sandbar the next morning. The wild rays headed out to deeper water during the day and returned to South Sound at night, moving around farther and more frequently than their human-habituated counterparts.

"The supplemental feeding reversed the activity pattern," Corcoran said. "It changed from resting during the day and foraging at night to reversal of that pattern." The researchers concluded that tidal phase had no effect on the animals' activity space.

The scientists also noted that the fed animals were much fatter than their wild cousins and tended to reproduce all year long on the Sandbar instead of in cycles.

Stingray City has become an incredibly popular marine recreation attraction on Grand Cayman in the Eastern Caribbean-situated Cayman Islands. Two main areas comprise the stingray attraction on Grand Cayman: a shallow, meter-deep (depending on tides) Stingray Sandbar and the five-meter deep Stingray City dive site. Boat and tourist congestion in these areas can be overwhelming. Aside from the feeding of atypical food items, disruption of natural feeding and reproduction cycles, and habituation to the presence of human activity, Stingray City is also home to some of the most egregious examples of unsustainable wildlife interactions.

A search on Google Images for "Stingray City" reveals thousands of images of stingrays being grabbed, prodded, restrained, fed, or lifted out of the water. And YouTube has over 600 videos of tourists and operators in similar interactions.

Len Layman, a photographer on Grand Cayman voiced his concern about this issue and even launched a website, StingrayCity.org, dedicated to promoting Stingray friendly interaction. As Layman describes,

"On a daily basis I see the rays mistreated over and over. Many of the offenders (marine recreation operators) do not know better, some just don't care and feel they will get tipped more by doing so. Some of the people just feel that because they have done it for years that it is OK and no one can tell them different, not even the experts such as marine biologists. There are even operators that show stingrays out of the water in their print advertising and on their web sites."

At this point, Grand Cayman's stingray "attractions" are cash cows for the Islands and the local government has no plans to shut down either Stingray City or the Sandbar. However, regulations limiting boat tour operators, limiting the number and duration of simultaneous boat tours at the Sandbar, and regulating the types and amount of food dispensed have languished since first proposed in 2006.

In the mean time, based on the financial successes witnessed with stingray feeding on Grand Cayman, similarly unsustainable copy-cat "Stingray Cities" are cropping up in other diving destinations throughout the Caribbean.

What is it about marine wildlife interactions (feeding and handling) that makes it so different a mindset for tourists and tourism operators than how they would otherwise behave in a terrestrial wildlife setting?