Sixteen years after a moratorium on fishing for sturgeon, the prehistoric behemoth may be bouncing back in the Hudson River.
For years after adult populations dwindled to near collapse due to overfishing and habitat disruption, the population of young Atlantic sturgeon in the Hudson remained low. But in 2012, scientists with the Hudson River Biological Monitoring Program saw a nearly six-fold increase in the catch rate.
“It’s probably one of the most encouraging things I’ve seen in six or seven years,” said Malcolm Mohead, an analyst with the National Oceanic and Atmospheric Administration.
Atlantic sturgeon are especially susceptible to sudden declines because of the long stretch of time it takes for young sturgeon to mature into sexually active adults. Among their many quirks, sturgeon have a transitional lifecycle that begins with fish developing in the calm nursery waters of rivers before graduating to ocean-dwelling as adults. Like salmon, the fish then return to river areas to spawn.
It can take the fish six to 25 years to reproduce, according to the World Wildlife Fund. At long last, said Mohead, “It looks like they are coming home and they are having babies.”
Human populations place unusual pressures on the fish, notably from worldwide demand for caviar— the unfertilized eggs of sturgeon. Supplies of the delicacy currently come largely from Russia and Eastern Europe, not the U.S. On the Hudson, human contamination, alterations of habitat and ocean harvesting of adult fish have impacted their ability to thrive.
They are peculiar fish – spiny, slimy, slow-growing and long-lived. When fully mature, Atlantic sturgeon can measure 14 feet long and weigh 800 pounds.
Shortnose sturgeon were among the first animals listed as endangered in 1973 with the adoption of the Endangered Species Act. Their numbers have already significantly improved. Atlantic sturgeon were not placed on the endangered list until 2009.
John Waldman, a professor of biology at Queens College said that the sudden spike in the numbers of young fish is a good sign that the natural condition of Hudson River ecosystem is improving, after years of protection under regulations like the Clean Water Act, the Clean Air Act, and laws like the moratorium.
“Maybe this is indicative of a major improvement and maybe it’s just a one-year blip,” Waldman said. “Even if it’s a one-year blip, it means there is a higher proportion of fish in the system that are young, and they are going to come back someday as breeders.”
With sturgeon hatched in 2011, scientists plan to document the population as accurately as they can before this new generation makes the move to the Atlantic.