Tag Archives: climate change

The Spy Who Came in From the Marsh: New Sensors Gather Intelligence on Storms Like Joaquin

October 2, 2015

Dear Joaquin,

I’ve been watching the news coverage of your impending arrival. They’ve been interviewing coastal scientists in the mid-Atlantic states. They’re onto you. Head out to sea!

Sandy

—–

Intrepid scientists from FWS and USGS venture out in Nor'easter conditions to to deploy sensors designed to measure wave dynamics during storms.

A team of intrepid scientists from US FWS and USGS venture out in Nor’easter conditions to deploy sensors designed to measure wave dynamics during storms. Credit: Laura Mitchell/USFWS

If you happened to be at Prime Hook National Wildlife Refuge on Friday, October 2 — just 48 hours before the anticipated arrival of Hurricane Joaquin — you might have wondered if you were witnessing a qualifying event for the next season of “Survivor,” or perhaps just an ill-advised dare.

You would have been witnessing something much more exciting: coastal resilience science in action.

In spite of the conditions — extreme high tides, poor visibility, gale-force winds — a team of scientists from the Coastal Delaware National Wildlife Refuge Complex and the U.S. Geological Survey were out on foot and in canoes installing wave sensors at docking poles, many of which were under water at the time.  

Perhaps it’s a little misleading to say the scientists went out “in spite of” the conditions; they went out because of the conditions. Prime Hook is one of dozens of study sites in the Surge, Wave, and Tide Hydrodynamics (SWaTH) Network – an effort initiated in the wake of Hurricane Sandy to measure wave height, force, speed, and extent during hurricane-induced storm surges. It’s just one of a suite projects supported by Department of Interior Hurricane Sandy Recovery Funding to help natural and human communities weather the storms that are predicted to become increasingly frequent and intense as a result of climate change.

The data collected by the SWaTH sensors will be used to refine storm-surge models, create more accurate flood forecasts, design more effective flood-protection infrastructure, and develop wiser land-use policies.

Although Joaquin veered off into the Atlantic before reaching Prime Hook, the preceding Nor’easter provided useful wave data for SWaTH, that will also provide positive reinforce for another project inspired by Hurricane Sandy: the restoration of 4,000 acres of marsh that had been impounded in the 1980s to create freshwater habitat for waterfowl.

Just after the turn of the 21st century, a succession of major storms breached the barrier dunes between Delaware Bay and the impoundments, inundating them with saltwater to the dismay of the freshwater vegetation within.

“Sandy was the final nail in the coffin,” explained Restoration Project Manager Bart Wilson. “About four breaches turned into seven, and suddenly we had this huge area of free-flowing water between the bay and the refuge.”

In the wake of Hurricane Sandy, Prime Hook received resilience funding to dredge 1.1 million cubic acres of sand from a historic salt marsh to restore natural flow, and ultimately, restore the system's natural capacity to serve as a buffer for storm surges.

In the wake of Hurricane Sandy, Prime Hook received resilience funding to dredge 1.1 million cubic acres of sand from a historic salt marsh to restore natural flow, and ultimately, restore the system’s natural capacity to serve as a buffer for storm surges. Credit: Richard Weiner

But Sandy was also an opportunity. Prime Hook received $38 million in recovery and resilience funding to fill the breaches in the barrier dunes, and dredge more than a million cubic yards of sand from the historic salt marsh channels.

“Once the breaches have been filled, and we have natural channels flowing again, the water level will drop, exposing mud flats that will recolonize with saltmarsh vegetation over the next several years,” Wilson said.

Bart Wilson

Prime Hook Restoration Manager Bart Wilson. Credit: FWS

Although the primary motivation for the project was to restore salt marsh habitat, Wilson pointed out that in the context of future storms, local communities will reap the benefits as well. Literally. As a result of severe flooding from storms, farmers neighboring the refuge have seen the edges of their fields go fallow. Thousands of acres of healthy saltmarsh would have provided a tremendous natural buffer for upland areas.  

“If we had a giant marsh where we have open water now, we wouldn’t even blink an eye during these storms,” Wilson said. “Seawater would wash over the dunes, saltmarsh grass would catch the sand, life would go on.”

It’s a plausible scenario, but Wilson explained that the added value of Prime Hook’s participation in the SWaTH Network is that it will enable them to quantify the value of the restoration project in terms of increasing storm-surge protection. By continually deploying the sensors in advance of storms throughout the multi-year restoration process, scientists will be able to measure how wave dynamics change as the area transitions from open water, to mudflats, to 50-percent vegetation, to a fully restored marsh.

“We can say that salt marshes reduce wave action and flooding, but it will be great to have data to back that up,” he said.

In time, that data can be used to support similar salt marsh restoration projects that will help fortify human and natural coastal communities that are most vulnerable to sea-level rise and major storms.

Considering climate change predictions, Wilson noted, “It’s great timing that we’re doing this now.”

Spread the word, Joaquin.

The Hybrid Zone

Saltmarsh Sparrows (shown) produce hard-to-identify hybrids with Nelson’s Sparrows. Image credit: K. Papanastassiou

Saltmarsh Sparrows (shown) produce hard-to-identify hybrids with Nelson’s Sparrows. Image credit: K. Papanastassiou

Picture, if you will, a coastal marsh in New England where closely related sparrow species — the Saltmarsh Sparrow and Nelson’s Sparrow— interbreed where their ranges overlap. The birds produce hybrid offspring that can backcross with either parent species, until a large percentage of mixed-species birds forms in the area.

You’ve just crossed into the hybrid zone.

Beyond TV science fiction, Kate O’ Brien, a biologist with the U.S. Fish and Wildlife Service’s Rachel Carson National Wildlife Refuge, has helped author a recent study of hybrid zones with lead author Jennifer Walsh and Adrienne Kovach of the University of New Hampshire, Gregory Shriver of the University of Delaware, and Brian Olsen of the University of Maine. The five are members of the Saltmarsh Habitat & Avian Research Program, a collaboration of academic, government, and nonprofit researchers focused on the conservation of tidal marsh birds.

Both the Saltmarsh Sparrow and Nelson’s Sparrows are considered high priorities for conservation in the region, and the Saltmarsh Sparrow in particular is considered globally vulnerable to extinction. O’Brien says to ensure both species have a secure future, the first step is making sure scientists know for certain which is which.

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“Even given the significant challenges the Saltmarsh Sparrow faces, it is a fortunate species to be the focus of numerous talented researchers in the SHARP community,” O’Brien says. “It is a species that has gone from relative obscurity to one of intense focus.  Only by learning more about the species will we be able to monitor, manage and conserve it.”  

O’Brien and the other researchers found that appearance alone is not enough to identify these hybrid zone birds, and that birds from further backcrossed generations were often indistinguishable from the parent species. Fifty percent of birds identified as pure Saltmarsh or Nelson’s Sparrows in the field turned out be the descendants of hybrids when their DNA was analyzed.

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Nelson’s Sparrow. Image credit: Andy Reago and Chrissy McClarren.

They examined birds in the hybrid zone on the coast of Maine, New Hampshire, and Massachusetts. Each bird was classified based on its appearance as a Saltmarsh Sparrow, Nelson’s Sparrow, or a hybrid, and then a blood sample was taken so that the accuracy of this identification could be confirmed with DNA.  The genetic data was compared with data the researchers collected on plumage, bill size, and body size to determine if physical traits could be used to predict genetic species and hybrids. While the physical traits could not distinguish pure species from hybrids, they could reliably separate birds with primarily Saltmarsh Sparrow gene pools from those with primarily Nelson’s Sparrow gene pools.

These findings have important implications given the restricted range of the Saltmarsh Sparrow. Currently about 150 miles (or 15 percent) of the range falls within the hybrid zone, where both species occur, while mixed individuals occur well beyond the boundaries of this zone. Since individuals thought to be either “pure” Saltmarsh or “pure” Nelson’s may frequently carry hybrid genes, the researchers suggested DNA identification may be required to ensure accurate monitoring of the degree of hybridization and the population status of Saltmarsh and Nelson’s Sparrows within this area. The jury is still out, however, on the significance of hybridization — particularly when it comes to adapting to climate change.  Some scientists theorize that novel gene combinations may result in increased adaptation and increased resilience to climate change, while others suggest they could result in decreased survival of hybrids. Only time — and future research — will tell.  

Learn more about this research here.

Everything’s coming up brook trout, and not a moment too soon

For anglers, citizens, and scientists alike, the Eastern brook trout is more than just a fish; it’s an icon.

It’s a prized catch, the official fish of nine states, and an aquatic “canary in the coal mine.” Because brook trout depend upon clean, cold water habitat, a lack of brook trout is a good indicator that something’s amiss.

What lies beneath? With sophisticated new modeling tools, resource managers can better protect cold water habitat that eastern brook trout depend upon in the context of a warming climate.

What lies beneath? With sophisticated new modeling tools that take climate change into account, resource managers can better protect cold water habitat that eastern brook trout and other species depend upon.

Well, something’s amiss alright. After more than a century of population decline resulting from habitat loss, and competition from invasive species, brook trout are starting to feel the heat from climate change as well.

Not only does that make matters worse for brook trout, it makes matters more complicated for resource managers. “The big three threats – climate change, invasive species, and land use – all interact, so they all need to be taken into consideration,”  said Mark Hudy, Science Advisor to the Eastern Brook Trout Joint Venture (EBTJV). Any one of them can trump success against the others.”

That means if you have pristine habitat with no invasive species, but the water temperature is rising: No brook trout. Or if the water is ice cold and there are no exotic competitors, but the adjacent land is being converted into a theme park: No brook trout.

Fortunately, partners from all sectors are joining forces to tackle “the big three” with the right tools, using the best available science supported by the North Atlantic Landscape Conservation Cooperative, the Appalachian Landscape Conservation Cooperative, the EBTJV, and others.  

“These new models that are coming out take into account these complex interactions to help partnerships direct their efforts, and invest their first dollar in places where they are mostly likely to be most successful,” said Hudy.

Here is a snapshot of three new tools that are throwing brook trout a life line in the face of environmental change:

  1. Riparian Restoration Decision Support Tool
  2. Chesapeake Bay Brook Trout Assessment and Decision Support Tool
  3. Forecasting Changes in Aquatic Systems and Resilience of Brook Trout

Some like it cold: The Riparian Restoration Decision Support Tool,  funded by the Appalachian LCC

The threat

Seemingly minor changes in temperature can have major ripple effects for populations of cold-water dependent species like eastern brook trout. Given the implications for freshwater resources from warming associated with climate change, resource managers need to act strategically to mitigate the impacts on aquatic communities.

The response

Researchers from the University of Massachusetts Amherst and the U.S. Forest Service developed a modeling approach that combines data on land cover, elevation, and aspect to help identify streams and rivers with the potential to maintain cold water in the face of rising air temperature, but lack adequate tree cover to shade water from increasing solar radiation.

The products

The online web-mapping tool allows resource managers to locate the best places to plant trees along stream and river banks within their jurisdictions to maximize shading over critical cold-water habitat throughout their range.

Learn more: http://applcc.org/conservation-design/gis-planning/gis-tools-resources/riparian-restoration-decision-support-tool

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Credit: USFWS

Finding the sweet spots for brook trout restoration:  Chesapeake Bay Brook Trout Assessment and Decision Support Tool, funded by the North Atlantic LCC

The threat

Scientists estimate that brook trout have been extirpated from 60 percent of their historic habitat in the Chesapeake Bay watershed, thanks to competition from invasive species and human development. With climate change posing increasing threats to habitat, it is more important than ever to preserve strongholds for these fish within this watershed.

The response

North Atlantic LCC-funded environmental consulting firm Downstream Strategies has developed 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 goal is to provide a tool for practitioners to identify ground-level restoration projects that will have a positive ripple effect for brook trout populations across the entire watershed.

The products

The data and modeling results from the assessment have been incorporated into a web-based decision support tool that enables users to:

  • Visualize and download data and model outputs
  • Establish conservation priorities based on user-defined ranking criteria
  • Calculate spatially-explicit predictions of brook trout response under various conservation scenarios
  • Assess conservation success within the context of future climate regimes.

Learn more: http://204.227.19.109/DS-USFWS-B/Index.html

Home is where the headwaters are:  Forecasting Future Changes to Aquatic Systems and Resilience of Brook Trout, funded by the North Atlantic LCC

The threat

Headwater streams are the primary habitat of eastern brook trout, and thus the best focus for conservation and restoration efforts to ensure a future for this species. But in order to prioritize which headwater streams to protect, practitioners need to know which streams can continue to offer the key conditions necessary for sustaining brook trout in the face of climate and land-use change.

The response

A team of scientists from US Geological Survey and the University of Massachusetts Amherst is developing a decision-support tool for prioritizing areas for restoration and protection efforts, and comparing alternative management strategies by predicting changes in stream temperature, flow, and brook trout occupancy based on how climate change and development are expected to impact air temperature, precipitation, and forest cover.

The products

A web-based Spatial Hydro-Ecological Decision System (SHEDs) allows practitioners to visualize predicted persistence of local brook trout populations under different climate change scenarios. The Integrated Catchment Explorer (ICE), a key component of the tool. which models current and future stream temperatures across the Northeast

Learn more: http://northatlanticlcc.org/projects/brook-trout-and-stream-temp-modeling/brook-trout-and-stream-temp-modeling