Badwater Basin

Earlier this month, I drove to Death Valley National Park to do some reporting for an on-going project. This was a few weeks before the current “superbloom” sprouted up, but we did see some pretty spectacular scenery while we were there. 

Badwater Basin, Death Valley National Park.

(Image by Emily Benson)

Badwater Basin, at about 280 feet below sea level, is the lowest point in North America. The water that collects there has nowhere to go except into the atmosphere. As it evaporates into the arid desert air, it leaves minerals and salts behind, forming salt flats in its wake.

A small pool of salty water sits at the edge of a boardwalk in the middle of the basin. A sign proclaims that the pool “is home to one of Death Valley’s rarest animals — the Badwater Snail. These tiny mollusks exist only in a few springs at the edge of Death Valley salt flats.”

And how did the snails get over the mountains that ring the bowl of the basin? A genetic analysis in 2008 suggested that the Badwater snails, based on the timing of their divergence from a coastal ancestor, likely hitchhiked a ride into Death Valley on migrating water birds.

A pool at the edge of the Badwater Basin salt flats.

(Image by Emily Benson)

Vanishing glaciers

The sky was cloudless, a spotless expanse of endless blue, and not a single breath of wind rippled the water of Bowman Lake, a long and slender finger of water nestled between two ridges in the northwestern corner of Glacier National Park.

After growing up on the east coast, nine years ago this summer I visited the American West for the first time, and I understood why Montana is nicknamed “Big Sky Country.” I spent eight weeks at the University of Montana’s Flathead Lake Biological Station, where my fellow students and I dove into our field ecology classes, exploring the mountains and lakes of northwestern Montana along the way.

We visited Glacier National Park on several of our field trips, and one day in particular sticks in my mind – the lake was a perfect mirror for the mountains and the sky, and it was too beautiful for us to leave without taking out our cameras.

The sky and surrounding ridges reflected in Bowman Lake, along with several other photographers, in mid-summer 2006.

(Image by Emily Benson)

The majestic scenery of Glacier National Park, however, is changing – scientists estimate that by 2030, all of the park’s glaciers will be gone, melted under the force of global climate change. As the National Park Service notes, “the park’s glacially fed streams provide a constant flow of cold water throughout the summer season, maintaining necessary water levels and regulating stream temperature for fish and other aquatic species. Plant and animal species throughout the park rely on this flow.”

One of those animal species is the western glacier stonefly, an aquatic insect that, in the past, has only been found in alpine streams in Glacier National Park.

Recently, a group of scientists (including one of the professors that I studied with during my summer in Montana) surveyed all of the locations where the western glacier stonefly has been found in the past, as well as some similar habitats, in order to determine whether their distribution is shrinking along with the glaciers in the park.

The researchers detected western glacier stoneflies in only one of the six streams where they’ve been found before; they also found the stoneflies in two new alpine sites within the park, as well as one site about 335 miles away in Grand Teton National Park.

The scientists note that further study on the “status, distribution, and vulnerability” of the western glacier stonefly is warranted, but the results they’ve already gathered “suggest that an extremely restricted historical distribution of [the western glacier stonefly] in [Glacier National Park] has been further reduced over the past several decades by an upstream retreat to higher, cooler sites as water temperatures increased and glacial masses decreased.”

At some point, the western glacier stonefly will run out of mountain as the population searches for higher and higher sanctuaries, and, left with no place to go, it may face extinction. Glacier National Park is still beautiful today, but it isn’t the same park that I visited nine years ago. In nine more years, will there still be a place within the park’s borders where the western glacier stonefly can feel at home?

An adult western glacier stonefly.

(Image by Joe Giersch/USGS)

Plants hitching a ride

Growing up, I spent my summers exploring the lakes of New York’s Adirondack Mountains (I recently wrote about one Adirondack lake in particular here). I loved to swim, but I did not love swimming through patches of plants growing up from a lakebed – the feeling of their tendrils swaying in the wake of my passing, clinging to my skin as if they wanted to grab my body and pull me down into the depths of the water, was enough to send me thrashing back to the lakeshore.

Eurasian water-milfoil, an aquatic plant native to Eurasia and northern Africa that has spread across much of North America, grew in such abundance in Upper Saranac Lake (a lake that I swam in many times as a child) that a local foundation raised $1.5 million to begin removing the plant from the lake in the early 2000s. Invasive aquatic plants often thrive and proliferate in their new environments so much that they crowd out native plants, degrade fish habitat, and clog waterways, preventing them from being used for boating or swimming.

The control effort in Upper Saranac Lake – which involves sending divers into the water to pluck milfoil by hand – has been largely successful at reducing the amount of the plant in the lake (in recent years, divers have collected roughly one-fortieth the amount of milfoil harvested at the beginning of the project), but if the removal stops, Eurasian water-milfoil could quickly rebound – meaning maintenance dives will have to continue, and someone will have to keep paying for them, indefinitely.

Dealing with invasive species in aquatic environments is expensive and time-consuming, and, as is the case with Eurasian water-milfoil in Upper Saranac Lake, they often cannot be completely eliminated. Perhaps the best offense, then, is a good defense – if invasive aquatic plants aren’t allowed into lakes to begin with, then no one has to dive down to the lakebed to remove them later.

One way for aquatic plants to spread among lakes is to hitch a ride on boats or trailers. If the bits of plant matter that get wrapped around a boat propeller or caught in the wheel wells of a trailer can survive out of water long enough to reach the next lake a hapless boat-owner visits, the plant might be able to spread to that lake. (This is why many states require boaters to wash their boats between lake visits.)

Research recently reported in the journal Hydrobiologia shows that some plant-parts are particularly adept at surviving dry spells. A team of scientists working in northern Wisconsin collected stems from two aquatic plants, Eurasian water-milfoil and curly-leaf pondweed, as well as buds from the pondweed, allowed them to dry outdoors (in order to simulate the conditions plants caught on a boat or trailer might experience), then placed them back in tubs of water to see if they were still capable of growth and, presumably, establishing themselves in a new lake.

Single plant stems were able to grow after up to 12 to 18 hours of drying, and stems that were coiled, as if twirled around a boat propeller, grew after up to 48 hours out of the water. The curly-leaf pondweed buds were able to survive for the longest – some sprouted after 28 days on land.

“The high cost and difficulty of eradicating introduced invasive species makes preventing secondary spread a management priority,” the authors write. Knowledge of how aquatic plants are able to spread between lakes, and how long they can survive out of the water, can help lake managers develop guidelines for cleaning boats and, hopefully, eliminate the need to send divers down to weed invasive plants from the beds of any more lakes.

Native aquatic plants are an important part of lake ecosystems, but invasive species, like Eurasian water-milfoil in North American lakes, can grow so much that they take over, killing other plants and preventing boating and swimming. 

(Image by dhobern via Flickr)

Shetland's wind

The first thing I noticed about Shetland – a series of islands off the northern coast of mainland Scotland – was the lack of trees. The second thing was the water. Exquisite, turquoise seawater lapping at craggy cliffs, or, in some places, white sand beaches that looked like they’d been lifted straight from the latest ad campaign for some tropical resort, the only thing marring the picture the layers polar fleece and wool piled on the people there. In June.

A sandy shoreline on the coast of Shetland.

(Image by Emily Benson)

At roughly the same latitude as Anchorage, Alaska, mid-summer weather in Lerwick, the capital of Shetland, can be pretty chilly – typical temperatures barely hit 60°F on the hottest days of the year.

There are some trees in gardens and yards in and around Lerwick, but outside the town, the landscape is dominated by grass-covered hills. Trees once grew throughout the islands, but most were long ago cut down for firewood, and the ubiquitous presence of grazing sheep has kept the forests from growing back. I visited Shetland for three weeks in June almost 10 years ago (I was working on a project that had to do with modern interpretations of traditional folk art). If the wind came up when I was out walking in the hills, surrounded by nothing but open space, it felt as if the whole world was blowing by.

Rocky coastline in northern Shetland.

(Image by Emily Benson)

Recent research conducted by a team of scientists at the Scottish Marine Institute suggests that the same winds that I found overpowering on land might be changing the dynamics of algae blooms at sea. Seafood production, including catching or farming fish and shellfish, is a major component of Shetland’s economy; over the past few decades, blooms of Dinophysis, a dinoflagellate that produces toxins responsible for diarrhetic shellfish poisoning, have periodically threatened shellfish production and led to closures of shellfish harvesting areas. In order to predict when and where Dinophysis population booms might occur, these researchers turned to wind records.

I’ve written before about predicting algae blooms based on temperature; the blooms off the coast of Shetland appear to be increasing faster than Dinophysis can grow, suggesting that seawater containing Dinophysis cells is being blown in from other locations and that wind, rather than temperature, might be a good bloom predictor in this system.

The largest Dinophysis blooms the scientists studied occurred during the summers of 2006 and 2013; during those years, the prevailing summer winds were more westerly than in other years, when they tended to come from the south. The researchers suspect that the westerly winds blew in water full of Dinophysis, a supposition supported by their observation that water samples from sites on the eastern side of Shetland, protected from the westerly winds, contained fewer Dinophysis cells than samples from the western side of the islands.

“As the frequency of harmful algal blooms around the globe is perceived to be on the increase,” the scientists write, “and as the levels of investment in aquaculture rise, an understanding of their underlying causes . . . is more important than ever.”

When I recall standing on the stark cliffs and beaches of Shetland’s landscape, bundled in sweaters and a hat in June, it’s not hard to believe that wind may be exacerbating harmful algae blooms – in Shetland, wind seemed to be a driving force behind many things.

A storm blowing in on a windy day.

(Image by Emily Benson)