Rock stacking, often seen in rivers and along trails, involves arranging stones into human-made piles known as cairns. This practice has ancient origins, traditionally serving purposes such as marking trails, commemorating events, or designating burial sites. In modern times, the construction of these rock stacks has seen a resurgence, frequently driven by artistic expression, meditation, or the desire to capture aesthetically pleasing images for social media. While rock stacking may appear to be a harmless and creative activity, it carries substantial negative consequences for river environments and the overall outdoor experience.
Disrupting Aquatic Ecosystems
Moving rocks within a river directly harms the diverse array of organisms that inhabit the riverbed. River stones provide shelter, foraging grounds, and breeding sites for numerous aquatic creatures. For instance, aquatic insects and crustaceans like caddisflies, stoneflies, mayflies, and crayfish, along with salamanders, depend on stable rocks for their life cycles. Many of these invertebrates, which cling to or live under rocks, are exposed to predators, harsh currents, or lethal desiccation when their rocky homes are disturbed and removed from the water.
Fish species also rely on these undisturbed rocky substrates, particularly for reproduction. Many fish lay their eggs on or within the crevices of river rocks, and disturbing these sites can cause eggs to be washed away or expose vulnerable fry to predators. The collective impact on smaller organisms disrupts the intricate river food web, as these invertebrates serve as a primary food source for fish and other larger aquatic animals. Altering the riverbed by removing rocks can also increase water temperatures and decrease dissolved oxygen levels, negatively affecting cold-water fish species like trout.
Altering Natural River Dynamics
The act of stacking rocks can significantly alter the natural physical dynamics of a river system. When rocks are moved from their original positions to form stacks, they change the natural flow patterns of the water. This can create unnatural turbulence, divert currents, or slow water flow, leading to changes in the river’s structure. Such alterations often result in increased erosion of the riverbed and banks in unexpected areas.
Beyond erosion, rock stacking disrupts the natural process of sediment transport. Rivers naturally move gravel, sand, and silt downstream, a process essential for maintaining diverse habitats and shaping the river’s geomorphology. When rocks are removed, fine sediments previously trapped beneath them can be released, potentially smothering bottom-dwelling organisms and fish eggs by reducing the available oxygen. These disruptions can also impede the migration of fish to their spawning grounds, further impacting aquatic populations.
Diminishing Natural Beauty
Rock stacking can detract from the natural beauty and wild character of river landscapes. These human-made structures replace the organic formations of nature with artificial constructs, diminishing the sense of untouched wilderness that many seek in natural environments. This practice also directly contradicts the “Leave No Trace” principles, which advocate for leaving natural areas undisturbed. The presence of numerous rock stacks can spoil the visual experience for others hoping to connect with nature in its pristine state.
Unofficial rock stacks can create confusion and potential safety hazards. While some cairns are intentionally placed by land managers as navigational aids, haphazardly built stacks can mislead hikers, diverting them from established trails and potentially leading them into dangerous terrain. There is also a risk of unstable rock piles collapsing, which could cause injury to people, particularly children, who might interact with them.