Tourist activity disrupts sting ray behaviour

[Cetacea]

Biology professor's studies link tourist activity in Cayman Islands to disruption of stingrays

04/10/09 - Based on the research of a University of Rhode Island professor, tourist activity in the waters off the Grand Cayman Islands is responsible for the disruption of behaviors and an increase in the size of the female population in stingrays.

Biology professor Bradley Wetherbee has been studying the effects of sites where tourists feed wild stingrays in the Grand Cayman Islands since 2002.

In 2002, 2003 and 2008, Wetherbee traveled to Stingray City, one of the world's most popular dive sites, where he began his research.

"We were interested in how feeding the stingrays was influencing their behavior," Wetherbee said.

In the wild, stingrays are known to be nocturnal and maintain a diet consisting of organisms that dwell on the sea floor.

"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.

"They eat a lot of invertebrates, worms and shellfish," he said. "Their mouths are on the bottom, so they swim along and dig up stuff in the substrate mostly. They do catch little fish sometimes but it's mostly invertebrates."

Allison Seifter, a sophomore at URI who will be majoring in marine biology, helped organize the data from Wetherbee's research and presented it at the 2009 Northeast Undergraduate Research Symposium.

Seifter said the largest ray Wetherbee found was a female measuring 120 centimeters in diameter for its disk width.

"I was surprised that the females are a lot bigger than the males, almost twice as big," said Seifter. "With people feeding these rays, they're getting to really big sizes that they wouldn't usually grown to in the wild."

More here

[schizoidwoman]

I am a big fan of rays, but I don't like to read of them being discombobulated!

Edited April 13, 2009 by schizoidwoman