Hazel Lair, Contributing Writer
The Atlantic sturgeon, a federally endangered species of fish, has made its return to the James River for breeding season, despite worries regarding the population’s dwindling numbers. Now, the number of sturgeon is back in the thousands.
VCU’s Rice Rivers Center, also known as “VCU’s river campus,” has worked to tag and track the fish in order to protect the species.
In 2007, scientists believed that the James River had only 300 sturgeon left, according to Smithsonian Magazine. As of last year, Rice Rivers has tagged over 2,500 separate sturgeon, confirming that the species still has hope for recovery.
The Rice Rivers center has worked alongside the James River Association, the National Oceanic and Atmospheric The Upper Mattaponi Indian Tribe and the Pamunkey Indian Tribe to restore the sturgeon population, according to a previous report by the CT.
Researchers assist state and federal agencies on determining which habitats in the river are most important for “critical spawning, nursery and migration activities, as well as the importance of threats like collisions with large vessels and habitat loss,” according to the VCU Rice Rivers Center website.
Each year, as sturgeon sense the temperature drop in the fall, they come bounding up the James River, launching themselves into the air in a spectacular display of energy as they race toward their spawning grounds in Richmond. Another migration, a different group of the same species, occurs each spring.
Their skin is covered in rows of sharp, tough scutes for protection, but adults have no known predators apart from humans. They grow to their huge proportions in the deep, cool waters of the Atlantic Ocean, and can live for about 60 years, dwelling near the bottom where they forage for worms and shellfish with their barbels.
In the late 1800s, in a period called the “Caviar Rush,” people began fishing for sturgeon to collect their eggs, according to the New York Times Their value and popularity exploded and a century later, overfishing had collapsed the population, and their habitat was destroyed by pollution. Between 1887 and 1989, the number of Atlantic sturgeon caught per year dropped from 7 million pounds to 400.
According to VCU research assistant professor Matt Balazik, this was not good news for the James River’s ecosystem.
“[Atlantic sturgeon] are very important in resource transfer from the ocean to freshwater systems, the adults feed and grow offshore,” Balazik said. “When they move upstream to freshwater areas to spawn, they are bringing tons of marine-derived nutrients with them.”
Balazik does a variety of work with Atlantic sturgeon at the Rice Rivers Center. Much of his work centers around a system of telemetry tags and a receiver array that works to track sturgeon numbers and their movements.
“The best way to think about it is we put EZpasses inside of fish and then place tolls throughout the river and the tolls detect the EZpass when it moves by,” Balazik said.
Rice Rivers posts regular updates on Facebook so people can track where sturgeon are throughout their spawning season.
“The really cool thing is that researchers along the entire East Coast use the same equipment, so when VCU tags a fish in the James and it goes off New Jersey the tag gets detected by tolls up there,” Balazik said. “Most researchers send all their data into a community database and then the detections from the tags are sent back to the group that tagged the fish. It’s been a game changer in learning the behavior of these highly migratory fish.”
Despite the fish being protected by the Endangered Species Act and a decades-old moratorium on fishing, there are still ongoing threats to sturgeon, including ship strikes and poor survival rates.
“When the adults come back to spawn, they are getting entrained by ship propellers, which ends up killing them,” Balazik said. “We’ve been documenting this problem since 2007 … The James River population seems to have a juvenile survival issue. We and others catch plenty of adults but rarely catch juveniles. However, we can consistently catch juveniles in other river systems outside of the Chesapeake Bay.
We are not sure why, but the leading idea for most is that invasive blue catfish are devouring many eggs, larvae, and very young juvenile sturgeon.”
Balazik said the center is unsure why it is difficult to catch juvenile sturgeon, but the leading belief for most is that blue catfish are eating many eggs, larvae, and very young juvenile sturgeon.
“It’s looking much better compared to 30-some years ago when most experts thought the Chesapeake Bay population was functionally extirpated,” Balazik said. “There are a lot of adults out there and these fish live for decades, so they can sustain themselves with a few good spawning years every so often. It’s going to take time because the fish has a relatively long generation time compared to many animals.”