Weekly News Digest from Mote
|5-1-09 Friday's News@Mote|
|Published Friday, May 1, 2009 7:00 am|
Study Finds Drug Pollution in Wild Bull Sharks' Blood
Newborn bull sharks in Southwest Florida's Caloosahatchee River carry traces of drugs humans flush down the toilet, according to the first-ever study of pharmaceuticals in wild sharks, led by Mote Marine Laboratory and supported by the Charlotte Harbor National Estuary Program and the National Oceanic and Atmospheric Administration. The drug levels found were low enough that scientists wouldn't expect them to affect the animals' health, but they suggest continued monitoring.
The only sharks found regularly in fresh water, bull sharks encounter treated wastewater near its source. This water may carry active drug ingredients, which humans excrete after taking medicine, or introduce by flushing unwanted pills. Pharmaceuticals slip through treatment plants, which are designed to clean up other contaminants, such as bacteria and viruses.
Numerous U.S. streams have pharmaceutical pollution — usually at low levels — according to the U.S. Geological Survey. But scientists are only beginning to look for drugs in wild fish, and no one had tested wild sharks until now.
The 2006-2007 study, led by scientist Jim Gelsleichter formerly of Mote's Center for Shark Research, found miniscule amounts of active ingredients from a birth control drug and five antidepressants, as well as indirect evidence of a sixth antidepressant, in newborn bull sharks' blood. "The levels in the river are not levels for which you'd anticipate health effects in any fish" — or fisherman, said Gelsleichter. Rarely, he added, did a single bull shark's blood contain all seven drugs detected. "It's nothing for people to be Chicken Little about, and start saying that the sky is falling."
Gelsleichter, who is now an assistant biology professor at the University of North Florida, and co-investigator Nancy Szabo of the Univeristy of Florida tested 30 newborn sharks by comparing blood samples from bull sharks in the Caloosahatchee River — which has six wastewater treatment plants — to blood samples taken from sharks in the Myakka River, which has no treatment plants. "When you look at Myakka River versus the Caloosahatchee, only the Caloosahatchee sharks had measurable evidence of human drugs," Gelsleichter said.
Along with evidence of seven drugs in bull sharks, the researchers detected three drugs in Caloosahatchee surface water, and five in water entering the river from Fort Myers Advanced Wastewater Treatment Plant, including a birth control estrogen, antidepressants and an impotency drug. But the pharmaceuticals were diluted — as spread out as a drop or two of water in an Olympic swimming pool.
Gelsleichter recommends monitoring of common pharmaceuticals in rivers now, to avoid any surprises later. Access the full report (see pages 18-36).
Mote Monitors Rare Kemp's Ridley Turtle Nest
Sea turtle nesting season officially starts today, but Mote has already received a special surprise: On Saturday, April 25, an endangered Kemp's ridley turtle (Lepidochelys kempii), nested Saturday on Casey Key in Sarasota County. Kemp's ridleys are one of the smallest and rarest of the seven sea turtle species found worldwide.
The nest is only the third Kemp's ridley nest ever laid and verified in Sarasota County.
Beachgoer Alyson McCoy, of Ovieda, and staff from the Island House watched as the turtle came ashore to nest — during the day.
"My husband likes to dive for sharks teeth and I was sitting on the beach watching his dive flag when I saw the turtle," McCoy said. "I've seen loggerhead turtles nest before on New Smyrna Beach. But I've never seen one by accident and never in broad daylight!"
Thinking quickly, McCoy ran to her room and grabbed her camera. Mote staff were later able to verify that the turtle was a Kemp's ridley based on her images.
Kemp's ridleys are smaller, flatter and grayer than loggerheads, which usually emerge from the water to nest at night.
Saturday's nest was Sarasota County's third Kemp's ridley - the first two were verified in 1999. The species usually nests on beaches of Taumalipas, Mexico, and Padre Island National Seashore, Texas.
"It's exciting to have a Kemp's Ridley turn up in our county," said Tony Tucker, manager of Mote's Sea Turtle Conservation and Research Program. "In 2008, Florida only had 13 Kemp's ridley nests in the state. Kemp's ridley populations in Mexico and Texas are beginning to rebound strongly with help from a special program in Galveston, Texas, and protection at the nesting beach at Rancho Nuevo, Mexico. Also important is the fishing industry's adoption of turtle excluder devices, which protect turtles from being caught in shrimp trawls. Now, increases in Kemp's ridley populations might be bringing more stray, solitary nesters to Florida."
This rare nest on Casey Key will be checked daily by Mote's Sea Turtle Conservation and Research Program, which has monitored 35 miles of Sarasota County shoreline for more than 28 years thanks to about 200 staff, interns, and volunteers.
Mother's Day: Free Aquarium Admission for Moms w/Paying Child Ticket
Moms get free admission to Mote Aquarium on Mother's Day, Sunday, May 10, with a paying child ticket. Also, we're offering moms a 10-percent discount in our gift shops (does not apply to books, videos or previously discounted items). At Mote, you can learn how alpha female seahorses rule, how sea turtle moms lay eggs on Florida's coasts year after year and how mom (and dad) convict fish get room service meals delivered by their young. Happy Mother's Day from Mote!
Mote Aquarium is open from 10 a.m. to 5 p.m. 365 days a year at 1600 Ken Thompson Parkway, City Island, Sarasota. Admission prices are $17 for adults, $16 for seniors, $12 for kids ages 4-12. Kids 3 and younger get in free. Learn more at www.mote.org or call 941-388-4441.
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Mote Marine Laboratory has been a leader in marine research since it was founded in 1955. Today, we incorporate public outreach as a key part of our mission. Mote is an independent nonprofit organization and has seven centers for marine research, the public Mote Aquarium and an Education Division specializing in public programs for all ages.