Silent witnesses to the historic Christmas night crossing of the Delaware
Fisheries Biologist Catherine Gatenby dishes about fish!
On December 25, 1776 the watermen of Massachusetts navigated George Washington and his Continental Army across the Delaware River in the dark of the night. Below, huddling together in the depths of the river, were likely hundreds of witnesses to this historic event, shortnose sturgeon (Acipenser brevirostrum).
At 55 pounds and five feet long, shortnose sturgeon are large fish, but they are the smallest of the three species of sturgeon in eastern North America. Like their cousins the Atlantic sturgeon, they once occurred by the thousands in coastal rivers from Canada to Florida. Unlike Atlantic sturgeon, however, the shortnose spends most of its life in rivers – even in the cold of December.
By the end of the 19th century, overharvest had seriously depleted shortnose sturgeon populations. Damming rivers and using them as dumping grounds during the industrialization of the U.S. were final blows to sturgeon and their habitat. By 1967 only a few remnant populations existed, so shortnose sturgeon were included on the original endangered species list.
Today, after 40 years of protection by the Endangered Species Act and the Clean Water Act, shortnose sturgeon seem to be doing better in northern rivers. The Hudson River population alone has increased by over 400 percent since 1973.
Shortnose sturgeon have been found again in the Penobscot River in Maine. “Finding them at all is big; they haven’t been seen in the Penobscot since 1970” said Dr. Joe Zydlewski, Maine Cooperative Research Unit, U.S. Geological Survey – as he quickly suggested I speak with his wife, Dr. Gail Zydlewski, at the University of Maine.
In 2005 Dr. Zydlewski began a tagging program to monitor shortnose migratory behaviors and use of rivers in Maine after a fisherman hauled in a shortnose from the Penobscot. She and her team found that shortnose sturgeon in the Penobscot may migrate to the Kennebec River to spawn.
Once upon a time, the Penobscot River had huge populations of spawning shortnose and Atlantic sturgeon and the fish may yet live happily ever after there. Removal of the Veazie and other dams will restore access to 100 percent of historic spawning habitat for all sturgeon in the Penobscot River.
In the Delaware River, shortnose sturgeon may be rebounding as well, helping to repopulate the Potomac River via the Chesapeake and Delaware Canal. Shortnose were thought to be gone from the Potomac, but fishermen have reported catching them in the past 10 years and scientists with the U.S. Geological Survey and U.S. Fish and Wildlife Service identified a shortnose making a pre-spawning migration run in the Potomac River. “Although, we aren’t yet certain whether shortnose are spawning in the Potomac, we are certain suitable habitat exists for foraging, wintering and spawning,” said Mike Mangold, Service Biologist.
In 1992, the Service’s Maryland Fisheries Resource Office began managing the Atlantic Coast Cooperative Sturgeon Tagging program. “We are building a better understanding of how populations are faring in the wild, and where to focus efforts on restoring additional habitat for sturgeon” said Sheila Eyler, program coordinator.
As we reflect back upon the historic crossing of the Delaware this holiday season, let’s also reflect how fortunate we are to enjoy the heritage of our native fish populations and healthy, rich and productive rivers now and always.