Sturgeon returning to Hudson

It began as an ambitious project in the mid-Hudson River two years ago: to tag Atlantic sturgeon with specialized satellite and sonic devices to track migration and spawning patterns, testing whether conventional wisdom on this ancient fish still applied.

Though it is still too early to make conclusions, researchers at the New York State Department of Environmental Conservation (DEC) have seen surprising preliminary results, thanks in part to a 7.5-footlong fish called Minerva.

In the spring of 2006 and 2007, DEC marked 20 sturgeon with sonic tags that send a signal to remote receivers when the fish return to the Hudson to spawn. Over the same period, DEC attached satellite tags to 23 sturgeon to gather data about their travel once they leave the river. The first few fish spotted have produced unexpected data about their journey.

SONIC TAGS

It has been thought that sturgeon return to the Hudson every three to five years, based on studies of sturgeon eggs, though no one has actually verified the spawning frequency. So it was a curiosity when "Minerva McGonagall" was found in the river near Stony Point in April - just two years after she was equipped with a sonic tag. Then in May, along came "Arthur Weasley" and "R2D2,"also much earlier than expected. (All the fish tagged in 2006 were given names from the "Harry Potter" series; 2007 fish were named after "Star Wars" characters.)

Arthur Weasley is a male fish found near Hastings-on-Hudson, just two years after he was tagged near Catskill. R2D2 returned even sooner. He was found near Danskammer Point, one year after being tagged in Haverstraw Bay. It's premature to say whether these quick returns are anomalous.

Minerva has displayed other unanticipated behavior, said Amanda Higgs, estuary biologist with DEC's Hudson River Fisheries Unit. First, the female beat the males to the Hudson - an unusual occurrence. Second, she didn't swim straight to

the traditional spawning grounds,

+ near Hyde Park. Rather, she dallied near Haverstraw Bay and just recently moved up to the Hudson Highlands, still farther south than she's supposed to be.