Rivers of Shortnose Sturgeon in Winter

Article excerpt

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In the dark of the night, on December 25, 1776, the watermen of Massachusetts navigated George Washington and his Continental Army across the Delaware River. Below, in the depths of the river, were likely hundreds shortnose sturgeon (Acipenser brevirostrum) huddled together as they do in the winter, tails and heads merging into one large breathing organism--silent witnesses to this historic event.

At 55 pounds (25 kilograms) and five feet (1.5 meters) long, shortnose sturgeon are large fish, but they are the smallest of the three species of sturgeon in eastern North America. Like their cousin the Atlantic sturgeon (Acipenser oxyrhynchus oxyrinchus), they once occurred by the thousands in coastal rivers, from Canada to Florida. Unlike the 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, overharvesting had seriously depleted shortnose sturgeon populations. Damming rivers and using them as dumping grounds during the industrialization of the U.S. were additional blows to the species and its freshwater habitat. The species gained federal protection in 1967 under the Endangered Species Preservation Act, a parent to today's Endangered Species Act. It was among the first 78 species to be listed as endangered. At the time, just a few remnant populations remained.

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The Endangered Species Act of 1973 added habitat protections, which were missing under the Endangered Species Preservation Act, and passage of the Clean Water Act further benefited the species, and others dependent on clean, healthy waters. Today, after 40 years, the status of the shortnose sturgeon is improving in northern rivers. The Hudson River population alone has increased by over 400 percent since 1973--a success shared by many communities and organizations that have worked together to protect habitat in the river for decades.

In 2005, a fisherman hauled in a single shortnose from the Penobscot. The event spurred Dr. Gail Zydlewski and colleagues at the University of Maine to begin a tagging program to monitor shortnose migratory behaviors and use of rivers within the Pine Tree State. The team found that shortnose sturgeon in the Penobscot may migrate to spawn in the Kennebec River, a 170- mile-long (270 km) river flowing through the heart of Maine, which has been one focus for migratory fish habitat restoration.

One year into the project, researchers at the University of Maine confirmed a population of the endangered fish in Maine's Penobscot River--the first in nearly 30 years. The confirmation offers biologists hope that habitat conditions in the river have improved to the point where it can support a healthy breeding population. …