New possession and length limits went into effect this month on the Mississippi River and Lake Pepin under revised border waters fishing regulations set in partnership with Wisconsin.

The new limits are more restrictive to protect populations of walleye, sauger, catfish, crappie, sunfish, perch, sturgeon, northern pike, and white and yellow bass. In a news release this week, the Minnesota Department of Natural Resources described the changes as the first comprehensive update of regulations on Mississippi River border waters in nearly 70 years.

Kevin Stauffer, the DNR’s area fisheries supervisor in Lake City, Minn., said the overhaul only applies to border waters south of Prescott, Wis., where the Mississippi and St. Croix rivers converge. In addition, it doesn’t unify all fishing regulations along the Mississippi and Lake Pepin. For instance, three-line fishing continues to be legal only on the Wisconsin side.

Historically, fishing regulations regarding length of season, bag limits and length of fish restrictions have generally been more permissive on the river than on inland waters of either state, the DNR has said. “Even though the fishery has held up well, there is concern among biologists and anglers that the fishery may not be able to withstand these stressors and high levels of harvest going into the future,’’ the DNR said of the new regulations.

For Wisconsin, the new regulations will go into effect April 1. Here’s a partial list of what’s identical and new:

• Walleye and sauger bag limit for pools 3-8 has decreased from six to four.

• Crappie, sunfish and yellow perch limit has decreased from 25 to 15 each.

• White and yellow bass limit has decreased from 25 to 10.

• Catfish (channel or flathead) bag limit of 10 combined with one over 30 inches.

• Pool 9 walleye and sauger bag limit of six; 15-inch minimum for walleye; and all walleye 20 to 27 inches must be released.

• Shovelnose sturgeon below Red Wing dam, bag limit of three.

• Northern pike, bag limit of three, only one over 30 inches.

The DNR said river fishing regulations below Prescott remain unchanged for size, daily bag and length of season for bass, muskie, bullhead, rough fish, rock bass and lake sturgeon.