Stanislaus River green sturgeon

From October 2017, this photograph shows the first ever green sturgeon verified in the Stanislaus River. Skeptics doubted the San Joaquin Basin habitat could ever support sturgeon in general; believing that it could not spawn in the warm, shallow and sandy river. Photo courtesy of Kyle Horvath/Cramer Fish Sciences

Confirmed in Stanislaus River for the first time, a green sturgeon highlights benefits of longtime research and restoration efforts

By Steve Martarano
February 23, 2018

When a green sturgeon was detected, photographed and confirmed for the first time in the Stanislaus River in October 2017, longtime researchers in the San Joaquin Watershed did proverbial backflips over the news.

The green sturgeon discovery by Cramer Fish Sciences’ Kyle Horvath, in a section of the river near Knights Ferry, California, showed that multi-agency research and restoration efforts, spanning more than a decade, which were primarily focused on the more common white sturgeon in the San Joaquin, were having positive impacts on other species as well.

“There’s been increased awareness and collaboration in the San Joaquin Basin and South Delta because of our efforts studying white sturgeon,” said Donnie Ratcliff, U.S. Fish and Wildlife Service’s regional Central Valley supervisor for Fish and Aquatic Conservation. “I don’t know if 10 years ago anyone would have realized how significant this was. But with all the work and partnering we’ve done these past years, it was like a lightbulb going off.”

“I don’t know if 10 years ago anyone would have realized how significant this was. But with all the work and partnering we’ve done these past years, it was like a lightbulb going off,” said Donnie Ratcliff,  U.S. Fish and Wildlife Service’s regional Central Valley supervisor for Fish and Aquatic Conservation. Credit: USFWS

The elusive greens, which were listed as threatened under the Endangered Species Act in 2006, are regularly found in the upper Sacramento and Feather rivers.

While there have been angler reports of the armored, prehistoric-looking fish in the San Joaquin Basin for years, none had been verified, until the discovery by Horvath, outside the Delta further southwest on the Stanislaus River.

Horvath, a biological technician with Cramer, was fishing from the bank of the Stanislaus one Friday afternoon when he spotted what he believed to be a 4-6 foot long sturgeon in the water.

Over the span of the next week, he returned to the site twice to confirm his discovery. The first time he used an underwater camera, which captured imagery of what appeared to be a green sturgeon. Horvath returned a second time - this time to dive; while he didn’t see the green sturgeon, he took water samples.

Cramer used the samples to confirm the presence of the species through DNA testing.

Kyle Horvath, Cramer Fish Sciences, shown here on the San Joaquin Delta, found the first confirmed green sturgeon sighting in the Stanislaus River in October 2017. Photo courtesy of Cramer Fish Sciences

“Adding the process of validation, from visual observation, to imagery and then genetics, increases the public’s understanding that scientists work hard to get the right answer, especially when the data has potentially significant consequences,” said Cramer’s president Joe Merz.

“The recent verifications of white sturgeon spawning, combined with the green sturgeon verification shows that the upper San Joaquin has potential to support green sturgeon habitat,” said Joe Heublein, green sturgeon recovery coordinator with National Oceanic and Atmospheric Administration Fisheries.

This recent success story is more than a decade in the making: in 2006, the California Department of Fish and Wildlife made sturgeon research and monitoring a priority, working closely with the Service’s Lodi field station. While research and monitoring increased, state recreational fishing regulations were changed to prohibit the take of green sturgeon, and a more-protective limit was set on white sturgeon, said Marty Gingras, the state's Bay-Delta Region operations manager.

The following year CDFW began requiring sturgeon anglers to report catch locations. As a result of this reporting, the San Joaquin River was highlighted as a location where sturgeons were found. The Service took notice of those reports and assembled a field crew of primarily Service biologists in 2011 to begin sampling to detect sturgeon presence and spawning, and later tagging.

Skeptics doubted the San Joaquin Basin could ever support sturgeon in general; it was common belief that it could not spawn in the warm, shallow, and sandy San Joaquin River, except during flood years.

Former Lodi Fish and Wildlife Office biologist Zachary Jackson, a key part of the Service’s sturgeon research efforts for several years, holds a white sturgeon in the San Joaquin River in a 2017 photo. Credit: Laura Heironimus/USFWS

Yet the research may be proving the skeptics wrong; white sturgeon have returned to the San Joaquin River on several occasions. According to Ratcliff, sturgeon spawning success in the San Joaquin appears to be linked to the amount of water flowing into the river, water temperature and availability of gravel and cobble. This information will inform future management decisions aimed at improving habitat for the fish.

The field crew continues to obtain important data on sturgeon, with assistance from the multi-agency California Fish Tracking Consortium. The Consortium tracks the movements of various Delta species using acoustic transmitters implanted in individual fish that are detected at over 400 receivers throughout Central Valley rivers and the Delta.

The combined resulting data from the multi-agency research efforts have helped the Service’s Anadromous Fish Restoration Program and multiple stakeholders better understand the population.

“It is really amazing that 25 years ago we weren’t really talking about sturgeon in the San Joaquin,” Merz said. “Now, not only are they there, but reproducing as well.”

The white sturgeon monitoring crew continues to obtain important data, with assistance from the multi-agency California Fish Tracking Consortium. The Consortium tracks the movements of various Delta species using acoustic transmitters implanted in individual fish that are detected at over 400 receivers throughout Central Valley rivers and the Delta. The crew, shown here on the San Joaquin River near Lathrop are Graham Mytton (left), Laura Heironimus and, Zachary Jessee (right), all with the Lodi Fish and Wildlife Office’s Anadromous Fish Restoration Program. Credit: Steve Martarano/USFWS

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Steve Martarano

About the writer...

Steve Martarano is currently the public affairs specialist in the San Francisco Bay-Delta Fish and Wildlife Office located in Sacramento, California.

He has spent almost 30 years in both state and federal government public affairs after a 10-year stint at a daily newspaper in Sacramento.

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