Riverwalk wetlands: small habitats, big impacts

Photo courtesy Charles Martinez
A green-winged teal in the Pagosa Springs wetlands.

By Josh Pike
Pagosa Wetland Partners

Often, when I walk along the San Juan Riverwalk and pass the Ross Aragon Community Center, I am struck by the extraordinary biodiversity and verdant beauty of the wetlands lying between the Riverwalk and the San Juan River near the Town Hall. 

As an ecologist for Pagosa Wetland Partners (PWP), a local community environmental protection group concerned with protecting, preserving and enhancing our local wetlands, I am keenly aware of the unique characteristics of our local wetlands, from the geothermal sources which feed their distinctive water chemistry and prevent them from freezing in the winter to their fragile and unusual biodiversity. 

The impact of our downtown wetland extends well beyond the recreational benefits to our residents and visitors: It benefits wetlands across the entire region and particularly more mobile residents such as birds and insects. Here’s why.

A small patch of high-quality habitat like the Riverwalk wetlands can impact the surrounding area in several ways, firstly, as a place of refuge for wetland species during times of high stress. Such a refuge provides a nutritional and habitat resource for species that helps support them through difficult periods. This support can prevent them from being forced to migrate or from dying off. 

The two most challenging periods for wetland wildlife are during the high summer and in the winter. In summer, many wetland habitats, such as small ponds or creeks, may become dry or highly toxic due to high loads of cyanobacteria, thus depriving the organisms that depend on them of livable habitat. 

In winter, these same areas tend to freeze over completely, making them unusable for many species, particularly waterbirds. The warm water spring-fed nature of our Riverwalk wetlands makes it less susceptible to freezing, drying and toxic algae. In the summer, its consistent groundwater sources and moving water protect it from either drying up or becoming plagued by toxic algae blooms. In the winter, these same geothermal sources prevent our warm water wetlands from freezing like many of our other lakes and streams. This allows birds and other animals to find refuge during difficult periods. It’s not unusual to see various bird species such as green-winged teal along the wetlands well past their normal migration seasons. 

Our wetlands also serve a larger role in helping sustain metapopulations. Some populations of animals live entirely in a single patch of habitat, like a population of fish living in an isolated pond. However, many more live across separated fragments of habitat and frequently move between fragments, like geese moving among ponds and isolated wetlands. Populations with this type of behavior are referred to as metapopulations. Metapopulations are increasingly common in our fragmented and degraded natural habitats. These animal populations are dependent upon the broader network of fragments for quality habitat, resources and safe shelter. Together, these fragments allow its metapopulations to expand to a size that individual fragments alone could not support. 

The Riverwalk wetlands are not only a unique local animal habitat, they are a particularly important part of the larger wetland habitat within the broader network of small lakes, ponds and wetland fragments that spread across the county and state. 

Next time you walk on the Riverwalk, take a moment to look over the wetlands and think about the places the abundant wildlife came from. What reasons might have brought them here and what areas across the region might benefit from the resources these animals gain here?

I am a member of a group of local residents, PWP, working to preserve, protect and enhance our downtown wetlands for the benefit of all Pagosa residents and businesses. We are spearheading an effort to raise awareness of the contribution our local wetlands provide to our town and county. If you would like learn more about the wetlands or get involved with us in protecting our unique wetlands, you can contact PWP at Pagosawetlands@gmail.com.