July 13, 2016 — For years, scientists thought there might not be any native Atlantic sturgeon in the Chesapeake Bay. That idea changed in recent years, as biologists began netting hundreds of adults in the James River, and others began turning up in other tributaries.
Now, genetic analyses show the Chesapeake is home to at least two — and possibly more — distinct populations of the endangered fish.
DNA analysis shows that James River sturgeon and those recently found spawning next door in the Pamunkey River, a tributary of the York River, are not even particularly closely related, despite their geographic proximity.
The 138 Pamunkey fish sampled seem more closely related to what could be a third population farther up, and across, the Bay in the Nanticoke River where 15 adult fish have been caught — and released — the last two years.
It’s too early to say whether the sturgeon netted in the Nanticoke and its tributaries constitute a unique population, said Tim King, a fisheries biologist with the U.S. Geological Survey who did the genetic analysis. King said he would like at least 25–30 samples before offering a more concrete opinion about the Nanticoke sturgeon.
“It is way too early to draw any conclusions,” King said. “But it would seem that they are not James fish. They are genetically more similar to the Pamunkey fish than they are the James, but I am not willing to say that they are Pamunkey fish.”