Why determining the age of fish is so important for North Dakota biologists

BISMARCK — The North Dakota Game and Fish Department determines the age of about 1,500 fish a year on Lake Sakakawea.

That information, derived from age rings in a fish's otoliths, a small inner-ear bone, provides biologists with an array of data. Biologists can determine if a stocking year was successful, how strong of a year's population of fish have become, determine mortality rates, chart fish growth and other information.

In this segment, host Mike Anderson of the NDGF talks with Missouri River System fisheries biologist Russ Kinzler.

Kinzler says the oldest fish ever recorded through sampling on Lake Sakakawea was 27 years old.

“Fish tend to live longer and colder bodies of water and Lake Sakakawea has lots of deep, cold water so our fish tend to grow a little bit slower than say a fish in a small lake out in the prairie," he says.