Stripers evolved in the cold waters of the Atlantic. They thrive when transplanted to freshwater lakes, but mature striped bass in Texas are stressed by hot summers. Seeking cool water in the deep lakes, they sometimes descend into areas of dangerously low oxygen. Rivers, by contrast, feature cooler water that often flows from the deepest part of a lake. Flowing water contains more oxygen than still water.
Most rivers also receive lighter fishing pressure than lakes.
In a Texas lake, striped bass are frequently caught before they have a chance to reach their potential. When they successfully avoid fishermen, mature fish often succumb to Texas heat before reaching maximum size. Whether in a river or a lake, cool weather is striper season, and the best way to catch a big striper, says Lake Whitney fishing guide Greg Gates, is by tempting the fish with an oversized gizzard shad. Gates' clients catch about 100 stripers each year in the 15 to 20 pound range that's generally considered trophy size in Texas. Gates could catch more big fish, but he doesn't believe in pounding a school of oversized stripers.