Tag Archives: endangered fish

Secrets of the Lower Great Lakes: The search for lake sturgeon

Catherine Gatenby

Catherine Gatenby is a fish biologist with the U.S. Fish and Wildlife Service.

Lake sturgeon nearly disappeared from the Great Lakes 100 years ago. Discovering the secrets of their biology to help recover the species is a group effort. Today, Catherine Gatenby takes us on a journey to the Niagara River, Lake Erie and Lake Ontario with fish biologists who are diving deep into sturgeon waters to find answers we need for helping this ancient species of fish.

Out on Lake Erie in search of lake sturgeon. Photo credit: USFWS

Out on Lake Erie in search of lake sturgeon. Photo credit: USFWS

While the quest for lost treasure chests of information about lake sturgeon might not be considered fodder for an Indiana Jones movie, the discoveries may be more valuable than gold to fish biologists. The U.S. Fish and Wildlife Service’s Lower Great Lakes Fish and Wildlife Conservation Office and Northeast Fishery Center along with the New York State Department of Environmental Conservation, the U. S. Geological Services and Shedd Aquarium are working together to recover lake sturgeon.

Their pursuit to uncover the secrets of this ancient fish doesn’t include excursions into dark caverns or midnight camel rides across the desert. However, it does involve dives into the blue waters of the Niagara River and breathtaking adventures on the expansive Great Lakes.  It takes a dedicated team of scientists, engineers, boat captains and barge operators to restore lake sturgeon and its habitat

Lower Great Lakes Fish and Wildlife Conservation Office and the Northeast Fishery Center lake sturgeon restoration crew out on Lake Ontario. Photo credit: USFWS

Lower Great Lakes Fish and Wildlife Conservation Office and Northeast Fishery Center lake sturgeon restoration crew out on Lake Ontario. Photo credit: USFWS

Far less is known about the lake sturgeon in lakes Erie and Ontario than in the other Great Lakes. Questions we ask ourselves as we embark on this adventure include: How many sturgeon live here? Where do lake sturgeon spend their lives? Where is the best habitat for spawning and feeding? What do they eat? How many adults are reproducing? And the ultimate question we aim to answer is: How long before we can consider the population healthy and self-sustaining in the Great Lakes? 

“We collect valuable information by tagging wild fish. We learn about their movement, diets, hormone levels and genetic diversity to help us answer these questions,” says Dr. Dimitry Gorsky, of the Lower Great Lakes Fish and Wildlife Conservation Office. 

Fish biologists with the Northeast Fishery Center and the Shedd Aquarium in Chicago, IL implant a tag that will transmit valuable information on migratory behaviors of lake sturgeon. Photo credit: USFWS

Fish biologists with the Northeast Fishery Center and the Shedd Aquarium in Chicago, Illinois, implant a tag that will transmit valuable information on migratory behaviors of lake sturgeon. Photo credit: Shedd Aquarium

Biologists are observing an increase in lake sturgeon numbers in many remnant populations across the Great Lakes. “Over the past four years, we have captured and uniquely marked over 600 individual fish. We used to catch between 15 to 20 fish per year just 10 years ago,” reports Dr. Gorsky, “but we are steadily capturing more lake sturgeon, more than 100 fish each year. This summer, we have already captured nearly 200 fish and are on our way to a record year.”  

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Northeast Fishery Center biologist releases a wild lake sturgeon after collecting vital information that will help evaluate overall health of the population. Photo credit: USFWS

The age distribution of lake sturgeon are eerily similar among different populations as those observed in the lower Great Lakes; most are less than 25 years old, suggesting that this ongoing recovery is in response to large-scale actions that took place many years ago. The first of which may be the Clean Water Act of 1972, which set the table for preventing and removing pollution from our waters. Also in the 1970s, some U.S. states along with the Province of Ontario, Canada, enacted fishing closures on lake sturgeon to protect what fish were remaining, according to Gorsky.

Figure 1. Age distribution of lake sturgeon - oldest fish born in 1967 (1)

For species that delay reproduction, such as the the lake sturgeon which doesn’t reproduce until at least 10 to 15 years of age, it would naturally take decades to see an increase in population growth, assuming the causes for the decline have been abated,” says Dr. John Sweka of the Northeast Fishery Center. 

U.S. Fish and Wildlife Service fisheries biologists study the gentle and ancient lake sturgeon to help with it’s recovery. Photo credit: USFWS

U.S. Fish and Wildlife Service fisheries biologists study the gentle and ancient lake sturgeon to help with its recovery. Photo credit: USFWS

The combination of setting harvest limits and improvements in water and habitat quality is creating a favorable environment for lake sturgeon recovery. “It’s amazing that actions begun so long ago continue to be linked to improvements in our Great Lakes,” remarked Dr. Gorsky. “Perhaps the greatest secret lake sturgeon may have revealed to us is that recovery takes time.” 

Lake sturgeon in the Niagara River below Niagara Falls. Photo credit: USFWS

Lake sturgeon in the Niagara River. Photo credit: USFWS

Read more about the U.S. Fish and Wildlife Service’s high-tech tracking of lake sturgeon in the Buffalo Harbor, NY.

Read more about the Lower Great Lakes Fish and Wildlife Conservation Office and the Northeast Fishery Center

Dr. DeWayne Fox, Delaware State University aboard the Dana Christine boat evaluates growth of an Atlantic sturgeon collected from Atlantic Ocean in 2013 that was hatchery-reared at the Northeast Fishery Center and stocked into the Hudson River in 1994. Photo courtesy of the university.

Atlantic sturgeon return home!

Northeast Fishery Center scientist, Jerre Mohler, preparing to release this hatchery-reared juvenile Atlantic sturgeon into the Hudson River. Credit: USFWS

Northeast Fishery Center scientist, Jerre Mohler, preparing to release this hatchery-reared juvenile Atlantic sturgeon into the Hudson River. Credit: USFWS

You’ve probably heard of stocking hatchery-reared fish to help increase fish populations for recreational enjoyment and for food. But did you know that some hatcheries rear and recover endangered fish?

This work is very tricky, however, particularly for species such as the Atlantic sturgeon that live a long time, often 60 years, and don’t reproduce until they are at least 10 to 14 years old …or more. That hasn’t stopped our scientists at the Northeast Fishery Center.

Five Atlantic sturgeon populations were protected under the Endangered Species Act in 2012, including the New York Bight population, which is listed as endangered. Back in 1994, the center captured Atlantic sturgeon to rear juveniles, and later released four-month-old sturgeon to the Hudson River. Fifteen years later, in 2009, biologists captured a hatchery-reared, ripe male–ready to spawn–that had migrated back to where its parents had been captured back in 1994.

This hatchery-reared sturgeon had migrated with wild sturgeon, suggesting that hatchery fish are capable of behaving similar to their wild counterparts.

Just this past spring off Bethany Beach in Delaware, biologists with the Delaware State University and the boat crew of the Dana Christine captured a 150-pound, large ripe female from the same 1994 stocking effort. They tagged her with a device allowing scientists at the Maryland Fishery Resource Office in Annapolis, Md., to track where she goes to spawn and to monitor her migration.

Dr. DeWayne Fox, Delaware State University aboard the Dana Christine boat evaluates growth of an Atlantic sturgeon collected from Atlantic Ocean in 2013 that was hatchery-reared at the Northeast Fishery Center and stocked into the Hudson River in 1994. Photo courtesy of the university.

Dr. DeWayne Fox, Delaware State University aboard the Dana Christine boat evaluates growth of an Atlantic sturgeon collected from Atlantic Ocean in 2013 that was hatchery-reared at the Northeast Fishery Center and stocked into the Hudson River in 1994. Photo courtesy of the university.

And just like Henry Hudson who sailed up the Hudson River in 1609, and other great men and women that have been drawn to the Hudson Valley’s richness, this female sturgeon was tracked making a run up the Hudson River this summer to spawning areas near Hyde Park!

Indeed, several hatchery-reared Atlantic sturgeon have been recaptured since the 1994 stocking in the Hudson River, and our folks at the Maryland Fishery Resource Office report that this number continues to grow each year.

These major finds provide scientists proof that you can raise a fish outside of its natural home range in a hatchery with good culture protocols, and the fish will migrate out to the ocean at the appropriate time and become sexually mature like wild fish do.

Not to mention, these Atlantic sturgeon fingerlings were reared at a facility in the Susquehanna River Basin (Chesapeake Bay drainage), yet they still were able to imprint to the Hudson River for eventual spawning. So now we know that imprinting can take place after four months–an important piece of information if future restoration stockings are planned.

This is all good news for folks around the world looking for scientific tools to help us restore and recover depleted fish populations.

Read more about our work to recover Atlantic sturgeon!

Yellowfin madtom. Credit: Mike Pinder, Virginia Department of Game and Inland Fisheries

Mini catfish swims back South

Yellowfin madtom. Credit: Mike Pinder, Virginia Department of Game and Inland Fisheries

Yellowfin madtom. Credit: Mike Pinder, Virginia Department of Game and Inland Fisheries

A small, minnow-sized catfish tinged with yellow has made an encouraging comeback, taking again to creeks and small rivers in southwestern Virginia and eastern Tennessee where it was once common.

J.R. Shute, co-director of Conservation Fisheries, Inc., holds up a bag of yellowfin madtoms. Credit: Shane Hanlon/USFWS

J.R. Shute, co-director of Conservation Fisheries, Inc., holds up a bag of yellowfin madtoms. Credit: Shane Hanlon/USFWS

The yellowfin madtom (Noturus flavipinnis) once thrived in the Powell River and Copper Creek, a tributary to the Clinch River. These bodies of water are among the most biologically diverse aquatic ecosystems in the nation.

By 1969, biologists thought the fish was extinct, lost to sedimentation and water pollution from agriculture and coal processing.

But then the fish was discovered at two locations in Virginia and Tennessee, and the Service listed the species as threatened under the Endangered Species Act in 1977.

The Virginia Department of Game and Inland Fisheries and a number of non-profit organizations support the U.S. Fish and Wildlife Service in efforts to recover the species. The VDGIF has used ESA funding to conserve the threatened fish. A state grant awarded in 2006 helped purchase conservation easements on two properties totaling 184 acres along the Clinch River—a project that reduced sedimentation and improve water quality to benefit the yellowfin madtom and seven federally endangered freshwater mussel species.

Check out other stories of endangered plant and animal conservation in the Northeast – We’re sharing them throughout the year!

Conservation Fisheries, Inc., a non-profit organization in Knoxville, Tennessee, has also helped restore the species by raising the species in captivity, reintroducing it into its historic range, and monitoring its status.

This map shows all the streams where yellowfin madtoms can be found. Created by Kurt Snider, USFWS.

This map shows all the streams where yellowfin madtoms can be found. Created by Kurt Snider, USFWS.

In 1986, Conservation Fisheries, Inc., began its captive propagation program for the yellowfin madtom. Fourteen years of raising and releasing fish paid off when snorkeling biologists discovered the yellowfin madtom at three new sites in the Powell River from 2000 to 2003. They even found non-tagged fish, documenting successful breeding in the wild. …Keep reading this story!