Jurassic Pork

Long-distance migrations are essential to a fish that swam with dinosaurs.

Sportsmen and women enjoy catching paddlefish in large part due to the work of the USFWS and Oklahoma Dept. of Wildlife Conservation. (Credit Nels Rodefeld ODWC)

 

Paddlefish have been around since about the time coal was being made. Fossil records say so. Now paddlefish contribute to anglers’ creels, particularly in the spring as the big fishes follow their instincts to migrate upstream to spawn.

They grow like pigs, and by some accounts smoked paddlefish is better than pork cutlets. These Jurassic survivors are living through another age, one pocked by reservoirs behind lofty dams that block migrations. As reservoir building increased in the middle 20th Century, paddlefish numbers decreased. Tishomingo National Fish Hatchery in Oklahoma plays a pivotal point in conserving this fish that endures from a time long passed.

Paddlefish are odd looking creatures: all snout and a huge mouth under an over-built head. Their jaw is the only bone in their body; the rest of their “skeleton” is cartilage, similar to the matter that makes up the tip of your nose. Their paddle-like head, fully one-third of their body, is super-charged with nerves to sense their main prey: microscopic plankton. Paddlefish feed themselves by swimming with their over-sized mouth agape, filtering voluminous amounts of water to gather these finely sized foods.

These relicts from the primal past still swim segmented waters of the Mississippi, Missouri, Ohio, and Gulf Coast basins — from Texas to Montana. Dams have blocked migrations and access to upstream habitats such as shallow gravel bars used for spawning. Captive rearing in hatcheries is necessary in the near-term.

Captive culture has been good for paddlefish conservation, not to mention fishing. After a 50-year hiatus above Texoma Dam, paddlefish again swim the Red River on the Oklahoma-Texas line in harvestable numbers, put there by the Tishomingo National Fish Hatchery.

The hatchery has done the same at Oologah, Eufaula, and Kaw reservoirs in Oklahoma, and John Redmond Reservoir in Kansas.

Since taking on paddlefish culture in 1992 to stanch a decline in populations, more than 500,000 of the young fish have been released from the hatchery into waters where the big fish formerly swam.

Captive rearing and stocking will continue.

 

Biologist Brian Fillmore at Tishomingo National Fish Hatchery carefully inserts a radio transmitter into an anesthetized paddlefish with assistant from two colleagues. It was stocked in Caddo Lake. (credit Mike Montagne)
Biologist Brian Fillmore at Tishomingo National Fish Hatchery carefully inserts a radio transmitter into an anesthetized paddlefish with assistance from two colleagues. It was stocked in Caddo Lake. (Credit Mike Montagne)

 

Paddlefish fingerlings quickly turn into juveniles, growing one inch in length per week throughout the summer. Foot-long paddlefish in the thousands will be going in waters in Oklahoma, Kansas, and Texas this year. The design, according to Tishomingo’s manager, Kerry Graves, is to put paddlefish out to the point that the wild population is mature and reproducing on its own. The work is already paying off above Kaw and Oologah dams in northeast Oklahoma. Young, untagged paddlefish have been caught by biologists, indicating that they were naturally spawned.

In May, more than 550 paddlefish from the Tishomingo facility were stocked in East Texas’s Caddo Lake in partnership with the Texas Parks and Wildlife Department; 31 of the fish were anesthetized and surgically implanted with radio transmitters by hatchery biologists with help from the Texas Fish and Wildlife Conservation Office. The tiny devices emit signals to allow scientists to follow their movements and discern the habitats used by the fish at various managed river flows coming from a dam. These fish are replacing, in a sense, the 47 paddlefish that were similarly implanted and stocked in Caddo Lake in 2014. The radio batteries only have a one-year life span. The radioed fish will reveal to biologists the habits and habitats used by paddlefish.

A year is only a speck of time in the life of a paddlefish; they live up to 30 years, reach six feet in length, and fatten up to 200 pounds. Some of the tagged fishes stocked from Tishomingo National Fish Hatchery have been re-caught years later. One such fish recently pulled from Kaw Reservoir topped 100 pounds at four feet long.

Pulses of river flow in the springtime naturally signal paddlefish to migrate. And move they do — unfettered. One tagged paddlefish navigated through mainstream river locks down the Ohio River and up the Missouri River — 1,136 miles from Indiana to South Dakota. Its migration ceased at the toe of Gavins Point Dam.

Captive rearing then is needed to rebuild paddlefish populations — a species that has survived since the age of dinosaurs but now faces concrete edifices and altered river flows.

To learn more about fish migration and fishes near you, visit http://bit.ly/FishMigration.

 

Craig Springer, External Affairs, U.S. Fish and Wildlife Service – Southwest Region, Albuquerque, New Mexico.

 

 

About Craig Springer

Craig Springer's writing has been recognized with awards from the Outdoor Writers Association of America, Southeast Outdoor Press Association, and the American Fisheries Society.