The bright red line under the jaw, large red spots on the sides, and large black spots concentrated toward the tail of a Rio Grande Cutthroat Trout. Photo by Chris Johnson

BY ED MACKERROW
Chama Peak Land Alliance
Backyard Biodiversity Series

Welcome to Backyard Biodiversity, a series of educational articles brought to you in partnership with In Light of Nature, Chama Peak Land Alliance, and the Los Alamos Reporter. By highlighting the unique and special nature of our area, and in the hope that a small drop in the water will send ripples of opportunity, we hope that each of us can and will enhance our backyard with biodiversity.

Our writer Ed MacKerrow of In Light of Nature is a wildlife photographer, scientist, and conservationist. He has a PhD in physics and specializes in the study of complex adaptive social systems. He has provided scientific expertise to the U.S. government on a variety of topics, including forest ecology and wildlife conservation. Ed is president of the Friends of the Nambe Badlands, dedicated to protecting sensitive BLM lands in northern New Mexico, a board member of the Katmai Conservancy for Katmai National Park in Alaska, and has served as vice president of the Friends of the Bosque del Apache National Wildlife Refuge. Ed is committed to environmental stewardship and ethical practices in wildlife photography. He runs a blog called “In Light of Nature” that covers wildlife, conservation, and nature photography.

In the rivers of northern New Mexico, there is a struggle to preserve native species and the balance of the ecosystem. The Rio Grande Cutthroat Trout, New Mexico’s state fish, is facing significant survival problems. Once widespread in the Rocky Mountain region, the native trout now inhabits only 10% of its original range in New Mexico.

The Rio Grande cutthroat trout (native to the Rio Grande, Pecos River, and Canadian River basins in northern New Mexico and southern Colorado) and the Gila trout (native to the Gila River system in southwestern New Mexico and eastern Arizona) are the only two native trout species in New Mexico.

Hybridization with rainbow trout, competition, predation by non-native trout, and habitat destruction from grazing, logging, and residential construction have contributed to the reduction of the species’ distribution throughout its range. As climate change contributes to wildfires and droughts, Rio Grande populations are highly vulnerable to these catastrophic events. Joint management efforts with tribes, states, other federal agencies, and non-governmental organizations implement conservation measures such as removal of non-native species, chemical remediation, stocking of native trout in remediated/rehabilitated waters, and habitat improvement and protection to increase Rio Grande cutthroat trout populations throughout their historic range.

According to the U.S. Fish and Wildlife Service, there are 13 core populations of the Rio Grande Cutthroat Trout remaining in the wild, four of which are in the Santa Fe National Forest. The survival of these core populations is critical to the species currently being considered for listing. The Rio Grande Cutthroat Trout has evolved to thrive in the cold, fast-flowing rivers of northern New Mexico.

The introduction of non-native brown trout and rainbow trout has dramatically altered the ecological balance. These introduced species displace the native cutthroat trout for several reasons:

1. Adaptability: Brown and rainbow trout tolerate a wider range of water temperatures and habitat conditions.
2. Aggressive behavior: These introduced species often compete more aggressively for food and habitat.
3. Reproductive advantages: They may spawn at different times or have higher reproductive rates under certain conditions.
4. Size advantage: Brook trout in particular can grow larger, giving them an advantage when hunting and fighting for resources. The recent rediscovery of the San Juan Cutthroat Trout – long thought to be extinct – further exacerbates the situation. This native species has been found in small populations in the southern San Juan Mountains in Colorado and northern New Mexico. Their presence brings both hope and urgency to conservation efforts in the region.

Climate change and forestry are threatening native trout. Increasing wildfires are leaving burn scars that cause runoff that alters water quality and river habitat. Higher temperatures are leading to earlier spring flows and lower summer flows, stressing trout populations and shrinking suitable habitat.

Conservation efforts in northern New Mexico include:

1. Habitat restoration: Projects focus on improving river conditions, reducing erosion and improving spawning grounds.
2. Management of non-native species: Efforts to remove or control non-native trout in specific waters aim to give native species a chance to reclaim their historic habitats.
3. Reintroduction programs: Carefully managed programs are working to reintroduce the Rio Grande cutthroat trout into suitable habitats with a strong emphasis on maintaining genetic diversity.
4. Forest management: Improved forest management practices aim to reduce the risk of catastrophic wildfires and mitigate their impacts on river ecosystems.

As we look to the future, the fate of the Rio Grande Cutthroat Trout and the newly established San Juan Cutthroat Trout remains uncertain. But dedicated efforts to protect these species offer hope not only for the trout, but for the entire concept of conservation in the face of global environmental change.

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