End of the Line Near for Prehistoric Survivor?
DEC uses high-tech tracking in bid to save the Hudson's dwindling Atlantic sturgeon
May 27, 2008 - Albany Times Union
By Brian Nearing
ALBANY -- Answers on how to protect Atlantic sturgeon -- an endangered fish that is an icon of the Hudson River -- are being teased from the inky depths of the river and the ocean.
The mysterious movements of sturgeon, a prehistoric behemoth with leathery, sandpaper-like brown-green skin, are being revealed by tracking devices to create a road map of the fish's wanderings.
Clues from the those devices are showing sturgeon travel much farther south than originally thought, and may go into commercial fishing zones where they are caught unintentionally outside the range of protected waters.
"We have found sturgeon from the Hudson going as far south as Georgia," said Ellen Pikitch executive director of the Pew Institute for Ocean Science, which is doing a three-year study with the state Department of Environmental Conservation.
This range may suggest that protected waters need to be extended to shield sturgeon from being part of the accidental "by-catch" of commercially desirable fish, Pikitch said.
Studies show that the largest sturgeon population is in the Hudson, where numbers of juvenile sturgeon have dropped from about 20,000 in the 1970s to fewer than 5,000 in the 1990s, according to the National Oceanic and Atmospheric Administration.
One of the biggest questions so far, Pikitch said, has been why sturgeon numbers are not rebounding since the state adopted a ban on sturgeon fishing in 1996. Federal officials extended that ban along the entire eastern seaboard in 1999.
Those numbers are not rebounding, despite the fishing ban, Pikitch said. "We are not seeing any problems in the rivers, so something maybe happening while the sturgeon are in the ocean," she said.
This will mark the third and final summer that researchers go onto the river near Hyde Park, capture sturgeon in nets, bring the 5-foot-plus creatures to the surface and attach two types of high-tech tracking tags.
The DEC tags, now on 20 fish, allow researchers to use underwater listening devices to locate individual fish in the river, while the Pew tags on 23 fish transmit data to orbiting satellites months after the fish have returned to the ocean.
Tracing the path of sturgeon could point the way for wildlife officials to best help the fish rebound, Pikitch added.
Bony-plated sturgeon, which date back some 200 million years, are seen as living fossils. Unlike salmon, Atlantic sturgeon survive their spawning journey each spring up freshwater rivers and return to the sea.
Coming as far upriver as Albany, the fish can live up to 60 years, grow up to 14 feet long, and weigh upward of 800 pounds, according to records from the World Sturgeon Conservation Society.
State officials also are learning about how the fish moves in the river during spawning season, which starts in April and can last into late summer, when females return to the sea. The last of any lagging male sturgeons can linger in the river until almost November.
"We don't know a lot about their spawning areas, where the fish go in the river," said Kathy Hattala, a fisheries biologist with the DEC Bureau of Marine Fisheries/Hudson River Fisheries Unit.
A spawning ground around Hyde Park has been known since fishermen first took sturgeon, but tracking tags have hinted that the fish also may also spawn near Newburgh Bay, a section of river near Storm King Mountain about 65 miles north of New York City.
"We don't know yet whether this might just be a 'loafing area' for the fish," Hattala said. But identifying other spawning zones would help DEC consider regulations to better protect the fish in those areas, she said.
"We want to make sure the fish are allowed to spawn undisturbed," she said.
A female sturgeon usually doesn't begin to reproduce until it is 20 years old. The fish can then continue to spawn every three to five years for the rest of its life. And since sturgeon continue to grow regardless of age, the oldest fish, which produce the most eggs, are the most fertile.
Pikitch is waiting for June 15, when five more satellite tracking tags are scheduled to detach from the fish, float to the surface of the ocean, and begin transmitting data on the water temperature, light levels and depths to help recreate the sturgeon's path.
"Once we know where the fish go, it will help us decide what needs to be done to protect them," she said.
Brian Nearing can be reached at 454-5094 or by e-mail at firstname.lastname@example.org.
Link: Albany Times Union