Good Article on Sturgeon in the Delaware , from the
Wilmington News Journal.
It looked like a routine catch when state fisheries biologists, working in the Delaware River across from Wilmington, pulled in a net filled with white perch.
But as they began tossing the perch back into the river, a tiny green fish caught Matt Fisher's eye.
Turns out, it was a baby Atlantic sturgeon -- a fish so rare in the Delaware that until this discovery, no one was even certain they still spawned here.
Fisher picked up the sturgeon, grabbed a bucket, filled it with water and slid the fish in.
"This small fish means this is our fish, spawned here," he said.
It is the first confirmed evidence in 50 years that Atlantic sturgeon could be spawning in the Delaware Estuary.
Sturgeon are an ancient species that one Delaware researcher described as "dinosaurs with fins" because they were around at the same time.
Atlantic sturgeon don't have scales like rockfish or weakfish. Instead, they have five rows of bony plates called scutes. The fish have a hard snout and four whisker-like protrusions they use as sensors. Sturgeons tend to scoot along in the darkness of the bottom, feeding from the mud and sediment -- traits that make them difficult to find and study.
Historically, Atlantic sturgeon were found in all the major river systems along the Atlantic from Canada to Florida. The Delaware River had the largest population.
In the late 1800s, the fish were targeted for both flesh and their eggs, which were salted and sold as caviar. At the time, the Delaware River was the largest producer of caviar in the country.
River landings peaked in 1888 at 6 million pounds. By 1901, sturgeon landings in the Delaware were 6 percent of that.
The population never recovered. Once the breeding population was depleted, researchers believe other factors such as loss of habitat, saltwater intrusion and pollution slowed any recovery.
To hatch successfully, the sticky, sturgeon eggs must adhere to rock or hard bottom.
Adults are slow to reach sexual maturity. Females don't typically produce eggs until they are at least 16 and males aren't fertile until they are 12. Females produce lots of eggs -- anywhere from 400,000 to 8 million but they may only spawn every two to six years.
Federal and state officials have run surveys for years, as have university researchers. All had the same goal: trying to determine if the Delaware still had a spawning population of Atlantic sturgeon. Commercial fishing has been banned coastwide since 1998 in local waters and since 1999 in federal waters.
While rare, Atlantic sturgeon are not listed as a threatened or endangered species. There are active efforts to win its listing and the discovery of the baby sturgeon could have a significant impact on those efforts, said Maya K. vanRossum, of the environmental group Delaware Riverkeeper. If there is evidence of a breeding population, the species could be at tremendous risk and worthy of the highest levels of protection, she said.
In the past, fisheries biologists went out in late spring and set wide nets in an area around Pea Patch Island and to the north. They hoped to catch sexually mature adults. A big egg-rich female, for instance, would have been a strong indication of local spawning.
"We've caught 2,000" Atlantic sturgeon between three and five feet long, Fisher said.
But the fish were not big enough to be spawners and it turned out they were migrating through the estuary and had not been spawned in our waters, he said.
Sturgeon hatch in fresh water and over time migrate back to the ocean. They return to the place or their origin to spawn. Genetic markers in the fish help researchers know where a fish was spawned.
This year, researchers took a different approach. Rather than look for the large adults, they decided to use smaller nets and fish in the late summer. The target: baby sturgeon.
Four times each month, Fisher and state fisheries officials put their nets in the river.
Back in 1994, fisheries biologists caught two small sturgeons in their trawl nets, Fisher said. But they didn't take measurements from the fish -- the data that would help to identify them as Atlantic sturgeon rather than shortnose sturgeon.
Fisher said environmental conditions in 1994 were very similar to this year -- a cool, wet spring -- so he thought that if sturgeon were spawning, he might have a chance at catching one this year.
On Sept. 9, the crew set nets off Penn's Grove, New Jersey -- the area across the river from where the Christina River flows into the Delaware.
"There were about 80 white perch in the net," he said.
Normally, Fisher drives the boat, but with so many perch, he helped count and release.
That was when he found the 7-inch-long fish. It weighed less than 1 ounce. It fish was so small, Fisher said there was no question it was spawned this spring.
"I was in shock," he said.
Fisher said the little fish swam around in the bucket and then rested on the bottom until the biologists were through taking measurements. Fisher took a tiny piece of the tail to send out for genetic testing and the fish was returned to the river. It was too small to tag or outfit with a radio transmitter, but that didn't lessen the excitement over the find.
"We are ecstatic," Fisher said.