Some like it cold

For Eastern brook trout, a clean, cold, headwater stream is like that perfect house you dream about finding in the nicest neighborhood, with all the best amenities — high ceilings (tree canopy), infinity pool(s), and proximity to good schools (of prey fish).

Which headwater streams will continue to meet the needs of Eastern brook even as climate changes? A new model will help decision makers identify prime real estate for cold-water dependent species in the context of global warming. Credit: USFWS.

Which headwater streams can continue to meet the needs of Eastern brook trout in the context of climate change? A new model will help decision makers identify prime habitat for cold-water dependent species based on predictions about climate change. Credit: USFWS.

So it stands to reason the best conservation targets for this iconic fish would be … headwater streams! Just set aside the highest quality headwaters you can find and brook trout will prosper, right?

Not so fast. What if it turned out that dream home wasn’t going to be quite so dreamy in 20 years? Would you still invest?

When it comes to determining the best streams to protect now to ensure a future for brook trout, climate change is muddying the waters.

That’s because the changing precipitation patterns and warming associated with climate change are affecting key habitat conditions for brook trout — namely, stream flow and temperature — even in seemingly pristine headwaters. That means in order to prioritize which streams to protect today, we need to know which streams can continue to offer the key conditions necessary for sustaining brook trout tomorrow, 20 years from now, and beyond.

No, your real estate agent can’t help you find a brook-trout dream house, but a team of scientists from the U.S. Geological Survey and the University of Massachusetts Amherst can. Combining data from their own 15-year study on brook trout with data from several other studies, the scientists developed a model to forecast changes to stream temperature, flow, and brook trout occupancy across the region, based on how climate change is expected to impact air temperature, precipitation and forest cover.

The model feeds into a new web application — The Spatial Hydro-Ecological Decisions System (SHEDS) — that provides a single platform for resource managers to access a whole suite of tools designed to help them make smarter decisions about protecting freshwater aquatic habitat. The tools include a stream temperature database, a visualization tool for identifying priority catchments, and an interactive GIS map displaying data on Eastern brook trout.

Cold enough for ya? Eastern brook trout require water below 68 degrees Fahrenheit for successful reproduction. Credit: USFWS.

Cold enough for ya? Eastern brook trout require water below 68 degrees Fahrenheit in order to ensure successful reproduction. Credit: USFWS.

Good news for brook trout: SHEDS is just one of many projects supported by the North Atlantic Landscape Conservation Cooperative that can help protect and improve habitat for brook trout and associated species in the face of climate change by focusing on understanding the subtle links between climate, system, and species.

Good news for people: we are among the associated species. Turns out humans and brook trout benefit from many of the same things — shade trees, safe road-stream crossings, clean water — so if brook trout are happy, we should be too.

Here are a few other efforts supported by the North Atlantic LCC and the neighboring Appalachian LCC that are helping to make human and brook-trout communities more resilient in the face of climate change:

  • The North Atlantic Aquatic Connectivity Collaborative – A network of diverse partners working together to take on the enormous task of assessing and upgrading road-stream crossing infrastructure, such as bridges and culverts, across the Northeast region. Equipped with common protocols, a shared database, and hip waders, partners are going into the field to identify structures that pose the greatest threats to human safety and wildlife passage, and to prioritize upgrades and repairs that will reduce flooding risks and improve aquatic connectivity in their communities, and beyond. Funded by the North Atlantic LCC.
  • Riparian Restoration Tool for Climate Resilience – A web-based tool that identifies streams and riverbanks that lack adequate canopy cover and shade to prevent solar heating from climate change from making cold-water habitat too warm for brook trout. Anyone from a resource manager to a conservation commission member to a private landowner can use the tool to find out where to strategically plant trees along streams in order to mitigate the impacts of solar heating, and keep cold water cold for species like brook trout. Funded by the Appalachian LCC.
  • Chesapeake Bay Fish Habitat Tool – A model and accompanying assessment for the Chesapeake Bay watershed that predicts brook trout occupancy, evaluates habitat quality, quantifies how human use and climate change are likely to impact both, and identifies conservation priorities at multiple scales. The tool will allow resource managers  to identify ground-level restoration projects that can have a positive ripple effect for brook trout populations across the entire watershed. Funded by the North Atlantic LCC.

1 thought on “Some like it cold

  1. Catherine Gatenby

    One of the best explanations of habitat use and habitat preference I have ever read. Great job Bridget explaining what and why various characteristics comprise a fishes’s dream home.


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