Crawfish, also known as crayfish or crawdads, are present in Colorado, living in various aquatic environments across the state. These aquatic crustaceans are an established part of the state’s freshwater ecosystems, featuring a mix of both native and non-native populations. Their presence is relevant due to their role in the aquatic food web and the opportunity for personal harvesting. This article explores the specific species, their preferred environments, and the regulations governing their harvest.
The Presence and Species of Colorado Crawfish
Colorado’s waters host a variety of crawfish species, though the composition is heavily influenced by non-native introductions. The primary native species is the Northern Crayfish (Faxonius virilis), characterized by a reddish-brown body and found primarily east of the Continental Divide. The most concerning species is the highly aggressive, non-native Rusty Crayfish (Faxonius rusticus). This invasive species, identifiable by reddish-brown spots on its carapace, outcompetes native crawfish and feeds voraciously on aquatic vegetation and fish eggs. Its introduction, primarily via anglers using them as live bait, poses a significant threat to native fish populations and aquatic plant communities. The state also contends with the Red Swamp Crayfish (Procambarus clarkii), commonly known as Louisiana crawfish.
Typical Habitats and Distribution
Crawfish distribution is concentrated in lower-elevation plains and plateau regions, where water temperatures are warmer and more stable. They are less common at higher elevations and in cold, fast-moving mountain streams. The most productive habitats are reservoirs, lakes, and slow-moving streams with fertile, moderately turbid water. They seek shelter among rocky bottoms, cobble substrates, woody debris, or aquatic vegetation. While the Northern Crayfish prefers rocky crevices in streams, invasive species thrive in both lake and stream environments.
Regulations for Harvesting Crawfish
Anyone harvesting crawfish for personal consumption must possess a valid Colorado fishing license. Since crawfish are designated as a non-game species, there is no specified daily bag limit, and the state encourages the removal of established invasive species. Legal methods of take include crawfish traps, nets, and hand-catching. Traps must be marked with the harvester’s name and customer identification number. Any female crawfish carrying eggs must be immediately returned to the water unharmed.
Harvesters must adhere to strict regulations concerning the transport of live crawfish to prevent the spread of aquatic nuisance species. Live crawfish may be possessed and transported only east of the Continental Divide. West of the Continental Divide, the transport of any live crawfish is strictly prohibited. Colorado Parks and Wildlife recommends removing the tail meat and placing it on ice immediately after harvest, even east of the Divide. A recent regulation change allows for the possession of live imported Red Swamp Crayfish for human consumption for a maximum of 72 hours, though strict vendor requirements apply.