Nature at Risk: This dinosaur-era fish of the Delaware River is on the brink

Sturgeons have existed for 200 million years. The flesh and eggs of this huge, ancient, bony fish were likely staple food for the indigenous Lenni Lenape in our area. The enormous abundance of the native Atlantic sturgeon (Acipenser oxyrhynchus) is arguably one of the reasons human encampments along the Delaware River go back thousands of years.

Fast-forward to the 1800s, when the Delaware was known as the “caviar capital of North America.” An estimated 180,000 Atlantic sturgeon females spawned in the Delaware. More than 3 million pounds of sturgeon were taken from the River over just five years in the 1890s.

That was then. This is now.

Over-harvesting and other human impacts have shrunk the Delaware’s adult spawning population to fewer than 300. Because bony plates cover its body, the Atlantic sturgeon is safe from most predators, but not from human actions.

One of many subspecies of sturgeons, the Atlantic sturgeon is large, up to 6 feet long and 150 pounds, and long-lived, up to 50 years or more. After living and growing in the freshwater river where they were born, juveniles head downstream to the sea. Fifteen or more years later, they return to their home river when they are old enough to reproduce.

The Atlantic sturgeon was spared one human-caused negative impact: a dam proposed for the Delaware River. The proposed Tocks Island Dam was never built, thanks to unstinting and unrelenting work by local people and organizations led by Nancy Shukaitis.

Other rivers — and their fish — have not been so lucky.

According to the National Oceanic and Atmospheric Administration, “in the United States, more than 2 million dams and other barriers block fish from migrating upstream. As a result, many fish populations have declined.” In some cases, fewer than one-half of one-percent of historic fish populations remain.

Sturgeons are among the most endangered group of species on Earth. Humans overfishing to meet the demand for caviar and causing habitat loss, often by dams, are the main culprits.

Find out what is being done. Check out the World Wide Fund for Nature “Sturgeon Strategy” at https://wwf.panda.org/wwf_news/?270173/Saving-Sturgeons

Nature at Risk is a series published by Brodhead Watershed Association. See brodheadwatershed.org