Lacamas Lake - "Dead Zone"

"Dead Zone"

One of the reasons the lake cannot support many fish is because of severe pollution from phosphorus, nitrogen and ammonia. The phosphorus, nitrogen and ammonia collect in the lake water and the lake bed from polluted streams that run into the lake after passing through farm fields, barnyards and subdivisions.

As it is now, the 2.4-mile (3.9 km)-long lake is murky. The sun warms the top layer of lake water and makes it suitable for warm-water fish such as bass, bluegill and perch. The plants clog the surface of the lake to a depth of about 18 feet (5.5 m), so no oxygen from the air can penetrate to the deep, cold water at the bottom. The visibility of the lake is usually less than 1-foot (0.30 m). It has very green murky water.

As the undesirable plants die, their leaves sink to the bottom, where they decay, using up still more oxygen, making the colder depths barren and lifeless. The Washington Department of Fish and Wildlife makes the lake more fishable by planting brown or rainbow trout, but few survive year to year.