AmericanPaddlefish_MigrationandReproduction_Montagne_Mike_SanMarcosTX_20July2020_Reel4027.mp3

Mike Montagne [00:00:01] Over time, we've certainly seen that the declines are directly attributable to man-made barriers.

Mike Montagne [00:00:08] And, of course, as humans, it's what we do. We like to, we dam things up. And, of course, humans, we kind of need dams. We have it, we need it for water storage. We need it for flood protection.

Mike Montagne [00:00:20] But they often create large problems in the environment, such as sedimentation issues, erosion, channelization, loss of wetlands and, of course, habitat fragmentation.

Mike Montagne [00:00:33] But of course, as humans, we need those things. But they do cause a lot of problems out in the environment, not just for paddlefish, but for many species.

Mike Montagne [00:00:42] Now, of course, these paddlefish have evolved over hundreds of millions of years in natural river flows, which have never been dammed until we started doing it, until about the 1900s. Paddlefish have been known and documented to migrate over 2000 miles to reach their spawning areas, and so they need these large stretches of river to complete their life cycles.

Mike Montagne [00:01:06] And these barriers, these manmade structures, create barriers for them that they just can't get past to get to their important spawning habitats sometimes.

Mike Montagne [00:01:17] But perhaps more importantly than just the actual barrier itself, the structures alter the dynamics of the habitat and the hydrology of the river, which often alters the river in such a way that the spawning habitat that is available is no longer usable, say, it's now covered in silt, or the water's too fast-running where they need it, or too slow and too stagnant, and can't get enough oxygen in there to keep the eggs alive.

Mike Montagne [00:01:45] And we've also lost nursery habitat. These, these paddlefish are reliant on flooded bottomlands as well for nursery habitats for their young.

Mike Montagne [00:01:53] And so there's so many things that manmade structures can do beyond just to create a barrier for them to get past. And any one of them can make a break in that life cycle of paddlefish, and other species of fish, which they can no longer overcome.