Devils Lake to Introduce Grass Carp Next Spring
Lincoln City, OR – The Devils Lake Water Improvement District (DLWID) is planning to introduce sterile grass carp into the lake. Starting in spring 2023, staff will begin restocking the lake with this fish to manage plant growth and vegetation.
This is the latest effort in DLWID’s vegetation management to ensure a clean, healthy lake for all to enjoy. In recent months, a steady rise in weeds and vegetation has caused concern by nearby lake residents and visitors. Lake Manager Josh Brainerd explains why this is occurring and how introducing grass carp into the lake will mitigate this.
“We are bringing the grass carp back because they are an effective way of controlling weeds and vegetation in Devils Lake, which has seen a drastic rise in the past year,” says Brainerd. “The reason for this is due to several factors which can range from changing water temperatures to having more people on the lake.”
Grass carp are a species of fish that are commonly found in large rivers in China and Russia. These fish feed on a wide variety of aquatic weeds in natural water sources such as lakes, rivers, and streams. A well-fed grass carp can grow up to 29 inches in length and weigh over 20 pounds in less than two years. The average lifespan of a grass carp is between 10 and 20 years old. Grass carp, like all cold-blooded animals, feeding rates are determined by water temperatures. Their optimum feeding levels are typically found in water temperatures between 70- and 80-degrees Fahrenheit, making Spring and Summer the best time frames for stocking.
They were introduced into the United States in the early 1960s as a method of vegetation control. However, it was quickly discovered that grass carp reproduce at an alarming rate. In the 1980s, researchers and commercial producers began producing sterile grass carp by manipulating the number of chromosomes in their genes. Triploid sterile grass carp started being used as a safer means of vegetation control. Oregon law requires that any usage of sterile grass carp for vegetation control be verified and documented by the U.S. Fish and Wildlife service.
Currently, DLWID staff is working with the Oregon Department of Fish and Wildlife (ODFW) to create a plan for stocking and reintroducing the grass carp into the lake. The purpose of the plan is to lay out how DLWID intends to re-stock the lake, monitor the carp, and establish optimum feeding rates to ensure proper vegetation management. Staff will go before the ODFW Commission this winter to present the plan and answer questions. Once approved by the Commission, staff can begin implementing the plan in Spring 2023.