Atlantic & Shortnose Sturgeon

Acipenser oxyrinchus oxyrinchu & Acipenser brevirostrum

Cool Fact: Sturgeon have been around for more than 200 million years

Atlantic and shortnose sturgeon are the only two native species of sturgeon found in Maine waters. They are anadromous fish, which means they spend most of their adult lives in saltwater but migrate to freshwater rivers and streams to lay their eggs. Spawned larvae gradually drift downstream into brackish water, where they live for one to five years before moving on to the ocean to feed and mature into adulthood. Each spring, adults return to their freshwater birth (natal) river to continue the cycle; after spawning, they swim back downstream to the estuaries and coastal waters, where they spend most of their time feeding. Only about 1% of the world’s fish are anadromous, and they undergo complex physiological changes to transition between different water salinities.

Their historical and current range are river systems and coastal waters from New Brunswick, Canada, to Florida. The shortnose is an estuary species and spends less time in the ocean than Atlantics but has made migrations of more than 260 miles. Tagging studies indicate that immature Atlantic sturgeon travel not only along the East Coast, but as far north as Iceland when at sea.

The habitat and behaviors of these two species are very similar, but naturally there are some physical differences. The shortnose is smaller in size (3-4½ feet long and 50 lbs.) and has a larger mouth, but a smaller snout; it is often mistaken for a juvenile Atlantic. Atlantic sturgeon are the largest anadromous fish in Maine, typically 6-8 feet long and 300 lbs., but have been recorded at 14 feet long and 800 lbs. Shortnose are yellowish-brown, with white to yellow bellies and usually a black head, back, and sides; Atlantics are bluish-black with olive brown backs, paler sides and a white belly.

Spawning migrations are dependent upon water temperatures, but males usually begin moving upstream in March/April as waters begin to warm; females follow days or weeks later. Fall spawning runs begin in August/September as water temperatures drop, with females again following later. Currently, the only known spawning area for Gulf of Maine Atlantic sturgeon is in the Kennebec River. Shortnose spawning occurs in the Kennebec and Androscoggin Rivers, but are often seen in the Penobscot, St. George, Medomak, Damariscotta, Sheepscot, Saco, Narraguagus, and Presumpscot Rivers as well.

During the summer, sturgeon can be seen leaping out of the water (breaching). Popular places in Maine to see them do this are the waterfronts of Bath, Gardiner, Hallowell, Augusta, Brewer, Bangor, and Brunswick. They can also be seen from the beaches of Scarborough and Saco. Scientists speculate breaching is a means of communication as well as a way to dislodge parasites or regulate their swim bladders.

Both species have five major rows of external, bony plates (scutes) that run the length of their body. They are bottom feeders, and their small mouths are located on the underside of their heads, behind protruding snouts that have four whisker-like projections called barbels, which are sensory organs used to locate prey in the soft mud or sand. They don’t have any teeth, so they use their mouth like a vacuum to suck up worms, insects, shrimp, baby crabs, mollusks, sand lance, and other bottom-dwelling fish.

Some 4,000 years ago, Native Americans harvested sturgeon for their meat, eggs (roe), and oil; by the mid-1800s, sturgeon provided a thriving and profitable fishery. Much as with miners out West, people came to the eastern U.S. to cash in on the available caviar, creating what became known as the “Black Gold Rush.” Historical landings records didn’t differentiate between Atlantic and shortnose sturgeon, so it’s been difficult to determine population trends of either species. As is often the case in harvested species, they were exploited and populations declined. More than seven million pounds of sturgeon were caught in 1890 alone. By 1920, only 23,000 pounds were caught, reflecting a drop of more than 99%.

Primary threats to sturgeon are entanglement and/or bycatch in fishing gear, habitat degradation (dredging), water quality, habitat impediments (e.g., dams and other barriers that block access to spawning areas), vessel strikes, and changing environmental conditions. Industrialization and development have impacted sediments and water quality by introducing nutrients and toxic  chemicals. Warmer temperatures and decreased dissolved oxygen concentrations can reduce the survival of juveniles; growth and even lifespan are correlated with water temperature.

Shortnose sturgeon were originally listed as an endangered species in 1967. The Atlantic States Marine Fisheries Commission enacted a coastwide moratorium on sturgeon fishing in 1998. Federal listing for Atlantic sturgeon under the US Endangered Species Act followed in 2012.

If you find a stranded, injured, or dead sturgeon, please report it to NOAA Fisheries at (978) 281-9328 or send an email to noaa.sturg911@noaa.gov.

More “Cool Facts”

• Sturgeon have been around for 200+ million years.
• Sturgeon were the primary food source that saved the Jamestown settlers in 1607.
• Sturgeon can hold their breath for up to an hour while searching for food.
• Females can lay between 1,000 to 5 million eggs in shallow waters.
• People used to believe that catching a sturgeon brought good luck.

Written by Jayne Winters – May 22, 2026

Resources:

• https://www.fisheries.noaa.gov/species/shortnose-sturgeon
• https://www.fisheries.noaa.gov/species/atlantic-sturgeon
• https://www.blueplanetaquarium.com/blog/learn-all-about-sturgeon-fish/
• https://www.diy.org/article/atlantic_sturgeon
• https://en.wikipedia.org/wiki/Shortnose_sturgeon
• https://en.wikipedia.org/wiki/Atlantic_sturgeon
• https://www.maine.gov/dmr/fisheries/sea-run-fisheries/sea-run-species/shortnose-sturgeon
• https://www.maine.gov/dmr/fisheries/sea-run-fisheries/sea-run-species/atlantic-sturgeon