Aug. 12, 2012

One hot, sunny morning in late June, Amanda Higgs, a fisheries biologist with the New York State Department of Environment Conservation’s (DEC) Hudson River Estuary Program, was fishing for Atlantic sturgeon, the Hudson’s largest and most ancient fish. Historically reaching a length of 14 feet and weighing as much as 800 pounds, the sturgeon have been roaming the world’s oceans and rivers for 85 million years and are  evolved from an ancestor that dates back to the dinosaurs.

For countless millennia, these ocean-dwelling fish have been swimming up the Hudson and other East Coast rivers in the spring to spawn, laying their eggs in the freshwater stretches above the salt line. But in the past century and a half, the sturgeon have been extirpated from many of their natal rivers and fished nearly to extinction.

Sturgeon bones discovered at archaeological sites along the Hudson date back 1,300 years and indicate the fish was a significant food for native peoples. In the 19th century, sturgeon was harvested in huge numbers for their meat, caviar and oil. When the shad had been fished out, commercial fishermen switched to sturgeon as a cheap, plentiful food for the burgeoning immigrant populations. But overfishing for “Albany beef,” as this poor man’s food was called, caused the population to crash by the beginning of the 20th century. The “caviar craze” of the 1890s decimated the Atlantic sturgeon in the Delaware River.

Fishing for sturgeon had resumed in modern times, and in the 1990s, you could order smoked sturgeon at New York’s Oyster Bar. However, fishermen were noticing that they were no longer catching juvenile sturgeon in their nets.  In 1995 the Hudson River Foundation, a nonprofit organization, funded research by experts that showed the numbers were dwindling to the point where the fish couldn’t sustain itself.

The next year the state closed the Hudson River fishery, followed by a coast wide, 40-year moratorium instituted by the Atlantic Marine Fisheries Commission, a regional regulatory organization, in 1998. This past February, four of the five Atlantic sturgeon populations, including the Hudson’s, were declared an endangered species by the National Marine Fisheries Service (NMFS).

Since 2006, the DEC has been tagging the Atlantic sturgeon during their June spawning run. On this particular morning, Higgs and her three assistants caught five male sturgeon in nets dropped from their boat off Norrie Point and Hyde Park. I was one of several reporters aboard Riverkeeper’s patrol boat, which pulled up alongside the DEC craft so we could get a close look at these mammoth fish.

Once caught, the fish, which averaged about six and a half feet in length, became surprisingly docile as they were slid into a narrow, water-filled pen onboard. Bottom feeders that suck up mollusks, crustaceans, worms, plants, and small fish with a mouth that protrudes like a tube, the sturgeon seemed crafted by a cartoonist: they had flattened, shovel-shaped snouts from which drooped a pair of barbells; small eyes, swiveling to show the whites; and a squishy, gaping mouth that sucked and gasped on the flat bottom of the head.

Yet their streamlined bodies, covered in olive-brown, beautifully patterned scutes, a kind of tough cartilage, were surprisingly graceful, not at all like the skinny, prickly creature depicted in blue on the DEC’s omnipresent “Hudson River Estuary” signs. The heaviest fish—68 inches long and 158 pounds—was missing a tail, possibly the result of a shark bite or propeller collision.

It was the day before the DEC’s sturgeon tagging program ended for the season. Later, Higgs noted it was the best year yet, with a record 123 sturgeon caught.  All were males: females, which are far fewer in number, don’t move around as much and would require a different kind of net, Higgs said. She added that at least a decade of sampling would be needed to accurately assess the fish’s population status. Nonetheless, since tagging began four years ago, the agency has noticed an encouraging increase in the numbers, she said.

From 2006 to 2008, the DEC attached sonic and satellite tags to some of the adult fish (presently, due to lack of funds, it is attaching metal tags donated by the U.S. Fish and Wildlife Service). The tags helped solve the mystery of where the fish go when they leave the river, revealing that the sturgeon tended to aggregate off southwestern Long Island, along the New Jersey Coast, and off Delaware and Chesapeake bays. Two tagged fish, however, swam as far as Nova Scotia and off the coast of Georgia.

The DEC has also learned more about the sturgeon’s movements in the river. It’s identified a previously unknown spawning ground off Newburgh and found that some adults returned to the river more frequently than expected. The DEC is also sampling juvenile sturgeon in the spring and tracked their seasonal movement from  West Point in the summer down to the estuarine waters of Haverstraw Bay and as far south as the Tappan Zee in the winter.

By correlating the locations of the sturgeon with a new, partially completed digital map showing the various habitats of the river bottom, the agency can pinpoint the habitats preferred by the fish and target those areas for protection.

Mitochondrial DNA analysis of the Atlantic sturgeon by Isaac Wirgin, an associate professor at New York University School of Medicine, has established that fish spawned from different rivers do have a distinct genetic footprint, proving that sturgeon return to their natal river to spawn. In addition, Wirgin’s information reveals the extraordinary importance of the Hudson River fish. In tracing the origins of aggregates of ocean-caught fish back to nine rivers, he has found that 42 percent are from the Hudson. The Hudson accounts for one of the largest populations of Atlantic sturgeon in America, if not the largest. (The NMFS notes on its website that the only other relatively robust population that’s been measured is sturgeon in Georgia’s Altamaha River.)

Wirgin has also discovered aggregates of mostly Hudson River sturgeon near the mouth of the Connecticut River in Long Island Sound and off Fire Island Sound. Such information is helpful in protecting the sturgeon from a prime threat, accidental catches in monkfish and other commercial fishery nets. Approximately 5,000 Atlantic sturgeon are caught in these nets each year, resulting in some fatalities. Restrictions on fishing in these sturgeon areas could reduce the amount of bycatch, Wirgin said.

Boat collisions are also a problem, particularly in the Delaware River. Although the young fish are increasing, PCBs could be a problem in some sections of the river, said Wirgin. He has researched the effects of PCB, by exposing fertilized sturgeon eggs to toxins at levels similar to what is found in the river sediment. The chemicals cause a variety of fatal deformities in the larvae, he noted.

Yet another concern is the impact that dredging and pile driving will have on the sturgeon when construction of the two replacement spans for the Tappan Zee Bridge commences. John Lipscomb, Riverkeeper’s patrol boat captain, fears that the proposed dredging of a trench across the entire river for installation of construction equipment would destroy important sturgeon habitat and create a barrier to sturgeon and other anadromous fish migrating up the river to spawn. Plans to install an electromagnetic power cable from Quebec in the river could also have a negative impact on the sturgeon and other fish.

Despite these concerns, many people involved with Atlantic sturgeon on the Hudson said they were surprised when the fish was listed as endangered. The closing of the fishery 15 years ago seems to have strengthened the Hudson population, they said.

“Anecdotally people are constantly running into sturgeon in the ocean and river,” said one source. Some people feel that the designation was politically expedient for the NMFS, which is under pressure to list species and had little to lose by listing the sturgeon, given the small size of the fishery.

But if the Hudson River Atlantic sturgeon are rebounding, it’s an anomaly, the one bright light in an otherwise bleak picture. Atlantic sturgeon from the Delaware, once the most robust population on the planet, are barely hanging on. The fish have been extirpated from nine of the 26 rivers in which they originally spawned.

Elsewhere in the world, relentless industrial activity—the building of dams, dredging, overfishing, and pollution—is wiping out these ancient fish. In Europe, where the sturgeon once ranged from the Baltic to the Black Sea, all that’s left is a tiny population in a river in northern France, according to John Waldman, a biology professor at Queens College who has been studying sturgeon for 20 years. Sturgeon have been wiped out in Asia’s Yangtze and Amur rivers, and Caspian Sea caviar no longer comes from wild fish.

Meanwhile, John Mylod, a fisherman based in Poughkeepsie, noted that the endangered listing is about to be contested. “Just last week, a couple of congressmen from New Jersey initiated legislation to request more money to determine the actual status of the Atlantic sturgeon populations, because nobody really knows. They want to delist the species.”

It’s a move former fisherman Steve Nack would welcome. Nack used to fish for sturgeon with his brother and father, Everett Nack, near Catskill, one of a dozen or so sturgeon fishermen on the river. The June run of sturgeon was part of a fishing cycle that started with shad in April and May (a fishery that has also been closed) and included eels all year round. “Most of the sturgeon we caught went to smoke houses,” Nack said.

Nack wishes the DEC would once again stock the river with fish from a hatchery, as it did in the 1990s. He said state officials had rejected this option because “the hatchery reared fish are considered genetically inferior, since they’re all hatched from one or two males and females, but I don’t buy that. The hatchery fish mix with the wild fish, and I don’t see why they wouldn’t come back here to spawn.

“I’m not against a sustainable fishery,” Nack said. But “on the river it’s been a very methodical chipping away of commercial fishing. Every time something closes, it never opens again.”

Mylod used to catch sturgeon in shad nets. The meat “is actually delicious,” he said. A female with eggs was worth a couple thousand dollars. However, after catching and tagging sturgeon for a researcher’s project in 1976, “we felt the animal was pretty impressive and didn’t feel we needed to take any more of them.”

A Rare Success Story

The Hudson is home to a second species of sturgeon, the shortnose, a smaller fish that’s been an endangered species since 1967. The shortnose spends its entire lifecycle in the river and hence was particularly impacted by pollution; its spawning grounds, located near Albany and the Troy Dam, were devastated by the disposal of raw sewage. However, thanks to clean up of the river, in the past 40 years the shortnose population has rebounded and is estimated to be around 65,000. Ironically, it has benefited from the invasion of the zebra mussel, which is a favorite food, according to biologist John Waldman.

“Most sturgeon populations in the world are grimly hanging on, and here we have a fourfold increase,” he said. “I can’t think of another species where that’s happened.”