Tag: fisheries research

Results: Great News for Shad

Standing on the bow of the boat, Steve Herrington exuded the excited energy of a kid reeling in his first fish. Or perhaps a more scientific version of the Crocodile Hunter, bubbling with intensity. Net in hand, he scooped up shad — a migratory fish species — quickly examining them before passing them off to fellow researchers.

As covered in yesterday’s blog, last year I spent a day with Steve on Florida’s Apalachicola River looking at Alabama shad, a fish that researchers hoped would benefit by a practice known as conservation locking—basically allowing fish to pass through dams by using the same lock system that enables ships to pass.

Herrington was then director of freshwater programs for The Nature Conservancy’s Florida program (he now holds the same position with Missouri). At the time, conservation locking on the Apalachicola seemed to hold great promise for shad, a migratory species. He estimated that conservation locking could result in a returning population of 60,000 to 75,000 shad, indicating a steady increase.

Fast forward a year later. Herrington is on the phone, and that same infectious enthusiasm is literally bubbling over. “Great news!” he exclaims.

And indeed, his research has yielded surprising results. Those initial estimates of 60,000 shad? Way low. Estimates now showed a 122,000 fish increase, with as many as 280,000 total shad now in the system.

“We can now confidently say that conservation locking works, and we’re seeing a substantial bump in the population,” Herrington says. “I don’t know that there are any other data out there that so convincingly demonstrates such effectiveness.”

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Research Results: If You Restore It, Will Pike Come?

It’s well known that some migratory fish species, like salmon, are able to trace their way back to the stream where they were born. However, conservationists have no idea if this is the case for hundreds of other fish species.

Do pike return to spawn in the streams where they were born, a la salmon?

Not necessarily, at least in the Green Bay watershed. If there’s suitable habitat, pike will find it and spawn. That’s the central finding of research conducted by the University of Wisconsin’s Pete McIntyre and Dan Oele.

This result may sound like a let-down, but in reality it’s a relief for conservationists in the Green Bay area. The Nature Conservancy and other conservation groups are focused on restoring streams for pike and other fish, but the best methods to accomplish that goal remain uncertain. If pike returned to their natal streams to spawn, they may never find a restored stream even if it contained suitable habitat.

That’s not the case, which is good news for conservation efforts.

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Big Fish: Return of the Alligator Gar

Once they were the river’s top predator: a fish that could reach ten feet or more, with thick armored plates as scales and imposing jagged teeth.

You would see their long, tooth snouts poking out from the river’s surface, gulping air—their adaptation for thriving in warm, deoxygenated water.

Alligator gar.

They thrived in a large swath of mid-western and southern waters, but by the early 1900s, they were already starting to disappear, a trend that continues to this day.

They were declared extinct in Illinois in 1994. But a new restoration and research effort aims to bring back these incredible fish, and help conservationists at other rivers and waters better protect them.

When fisheries biologists Rod Hilsabeck and Trent Thomas of the Illinois Department of Natural Resources decided to return the alligator gar to their state, they knew they needed a perfect location. The Nature Conservancy’s Spunky Bottoms Preserve fit everything they sought.

Formerly farmland, Spunky Bottoms is now 2000 acres of restored wetlands and uplands. It consisted of perfect gar habitat: backwaters and sluggish pools with lots of vegetation. It also was not connected to the adjacent Illinois River, making it easier for researchers to capture and study the fish.

Research is a key component to the reintroduction. Nathan Grider, a master’s student in biology at the University of Illinois-Springfield, is working with Dr. Michael Lemke and partners to study two key aspects of gar restoration.

They are studying how fast gar will grow when restocked into an area. They are also analyzing their diet, and in particular, if the gar will eat (and control) the non-native carp that swim Spunky Bottoms and so many other waters.

This information will help inform gar reintroduction and protection efforts throughout their range.

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