(Miami Herald)
Posted on Mon, May. 07, 2012
Everglades scientists play risky game of tag with near-extinct predator
By SUSAN COCKING
scocking@MiamiHerald.com
Sean McNeil and Jordan Kahn / PressLaunch.US
Researchers from the University of Florida captured, tagged and released two sawfish in the 13-foot range near East Cape Sable in Everglades National Park as part of a larger recovery project for the endangered species.
The boat captain and the scientist wielded their lasso like seasoned cowboys instead of fishermen. A good thing, since their lives literally depended on it: roping an upset, 13-foot-long, prehistoric creature waving a double-toothed saw in the water is just as dangerous as grabbing a bull by the horns.
"There's a swing," Captain Jim Willcox warned as the saw slashed the air. "Careful, it's pretty green."
But Willcox and Yannis Papastamatiou, a University of Florida scientist, managed to secure the line around both the saw and the tail of their quarry: an endangered smalltooth sawfish, the rarest marine species in U.S. waters. Now the huge brown creature lay quietly alongside their skiff near East Cape Sable in Everglades National Park, enabling them to safely complete their research mission.
"He's a good boy!" said UF research assistant Bethan Gillett, who had caught the giant fish on a rod and reel moments earlier.
The point of this hazardous maritime rodeo is for researchers from the Smalltooth Sawfish Recovery Team to learn as much as they can to help bring back one of the top predators in the marine ecosystem — nearly wiped out through its entire range over the past century.
"These guys started disappearing before we as biologists started figuring out they were going," said George Burgess, who runs a sawfish database at the University of Florida's Museum of Natural History in Gainesville.
Once common from New York south to Florida and west to Texas, these huge members of the ray family that can grow to 25 feet are rarely seen today, except for the waters of Everglades National Park and the Keys. Not a lot is known about their life history, but scientists say they may live 25 to 30 years, reaching sexual maturity after about 10 years. Females give birth to litters of 15 to 20 pups.
With its slow growth and late maturity, the smalltooth sawfish met its demise decades ago by becoming entangled in gill nets, being slaughtered by collectors of its bill, and squeezed by shrinkage of its shallow mangrove habitat. It was declared an endangered species in the United States in 2003. Its cousin, the endangered largetooth — formerly found in the Atlantic — now is functionally extinct in U.S. waters, according to Burgess.
Burgess says recovery of the smalltooth will take a very long time.
"Even with a total ban on death, it will take 100 years, and we're 10 years into that process, so we've got 90 years to go," he said.
Sawfish numbers are so beaten down that even scientific experts like Burgess and colleagues from the National Marine Fisheries Service and Florida Fish and Wildlife Conservation Commission must obtain a federal permit to handle the species. Anyone else who molests or harasses them faces a possible $10,000 federal fine.
This year, Burgess had a permit to tag 11 sawfish, which he did over the past couple of months with help from Willcox — a veteran Islamorada light-tackle guide — and several UF colleagues. They deployed the final two sets of tags on April 27 near East Cape Sable on two males in the 13-foot range. Both swam forcefully away when the procedures were completed.
Papastamatiou drilled holes in the animals' tough dorsal fins and fastened a cigar-shaped satellite pop-up tag, an acoustic transmitter tag and a small streamer tag with the research lab's phone number. The satellite tag records water temperature, depth and light levels at short intervals, then pops off after five months, broadcasting the accumulated data to a satellite, which sends it to the scientists' computers.
The acoustic tag beeps a signal to underwater listening stations that tell how many times the sawfish passes through the area. The three tags are intended to back each other up.
Willcox and the scientists have been catching and tagging sawfish in the park for about three years — not enough time to draw conclusions about the animals' movements or growth rates. Their ability to continue the research is imperiled by money problems: Federal funds are running dry, so they're seeking private donations.
"It's going to be a long haul," Burgess said. "We can't grow weary of the fight. Hopefully, our children and grandchildren will have a shot at this down the line."
One thing in the sawfish's favor is its charisma — a giant, brown apex predator that slashes its prey, mostly fish and some crustaceans, with its deadly bill. A recent study by scientist Barbara Wueringer of the University of Queensland in Australia found that the animals have a "sixth sense" in their bills — a series of pores that can detect movements or electrical fields of hidden fish or crabs.
The sight of a sawfish is awe-inspiring, Willcox says.
"When people see that for the first time, they feel like they've gone back in time," he said. "It's not something you want to mess with casually. That bill can come up vertically and take your head off. For me, it's like fishing in a tournament and getting a victory. It's about as big a rush as you can get in fishing — or anything in life."
These photographs were taken under the authority of NMFS Permit No. 13330.
Read more here: http://www.miamiherald.com/2012/05/07/v-print/2788243/everglades-scientists-play-risky.html#storylink=cpy
0 comments:
Post a Comment