17 May 2019

Why You Should Be Following #Fieldworkfail

by L. E. Carmichael

It's #FF (Follow Friday) over on Ye Olde Twitters, and if you're not already following #Fieldworkfail you should really get over there and get on that. Like right now.

When scientists write journal articles, they make it sound like they knew what they were doing every step of the way. #Fieldworkfail reveals the truth - they're making it up as they go along, pretty much like the rest of us.

Just with more bears.

While you're at it, hop over to this online shop where you can buy the hilarious book for 75% off. Also right now, because the sale ends today.

Happy Friday giggles, and have an awesome long weekend!



10 May 2019

Secrets of the Credit River - guest post!

Secrets of the Credit River
guest post by Nina Munteanu

 
I began my limnology career teasing out the secrets of stream life as a grad student at Concordia University, Quebec. My master’s research focused on several rural and urban streams in the Eastern Townships, not far from where I grew up.

Later, as a limnologist for various environmental consulting companies in British Columbia, I used stream macro-benthos communities—the critters that live on the stream bottom—as indicators of environmental impact from industrial discharges, agriculture and municipal development.

Macro-benthos are bottom-dwelling life you can see with the naked eye. They’re mostly made up of aquatic worms and juvenile stages of insect species (benthic invertebrates). Many of these insects start with an aquatic phase (often called nymphs or larvae) in which they voraciously feed and which lasts from several months to several years; they then emerge as adults to live briefly (from days to weeks) to mate and create new life.

Mayfly, stonefly and caddisfly larvae are commonly found in clean flowing streams; slower moving and polluted or turbid streams contain more worms, midges and amphipods.

Adult mayflies, stoneflies and caddisflies don’t feed. In fact, they don’t have usable mouthparts or digestive systems because they don’t need them—they don’t live long enough. The adult female mayfly (Dolania Americana) lives a brief five minutes. Once she emerges as an adult, she flies in a swarm of other mayflies, mates in flight and lays her eggs then dies and falls back into the water as food for fish, frogs, and other aquatic life. The stonefly (Gripopterygidae) larva, which clings to the underside of rocks and debris in fast flowing water, takes from one to three years to mature but once emerged will live from 1-4 weeks before dying. 


Stream ecologists identify benthic invertebrates by their form, but they also recognize them by how they feed; how they feed is largely determined by where they are in the stream and what is around them:

-Shredders use scissor-like mouths to cut and shred apart coarse particulate matter. These include amphipods, mayflies, stoneflies, midges, and some caddisflies.

-Collector–gatherers (e.g., worms, nematodes, crustaceans, and gastropods) use their broom-like mouths to sweep in fine and ultra-fine organic matter.

-Grazers or scrapers, such as beetles, mayflies, and stoneflies, feed on attached algae and biofilms. Their mouths chisel against periphyton (attached algae) on rocks, wood debris and aquatic plants.

-Filtering collectors, such as blackfly larvae, use their finely spun nets to collect suspended fine organic matter, which can include phytoplankton (floating algae). The caddisfly larva Arctopsychegrandis builds a rough house made from twigs, leaf fragments, and small pebbles and spins silk nets across its “door” to capture organic matter that flows in.

-Predatory benthic invertebrates, such as damselflies and dragonflies, have piercing mouthparts that act like a straw, allowing them to suck the liquid nutrients from their prey without having to chew or shred it. The dragonfly uses a hyper-thrust mechanism to give it a speed-boost as it chases prey. The dragonfly ejects water from its anal opening for a quick burst of speed; it’s just like a jet propulsion system.

Since 1909, when scientists Kolkwitz and Marsson showed that benthic invertebrates had specific tolerances to organic enrichment and other sources of pollution, ecologists have used these communities to study impacts to stream health from chemical pollution, flow disruption and habitat destruction. The EPT Richness Index was developed, based on the knowledge of certain pollution-intolerant groups. EPT stands for Ephemoroptera (mayflies), Plecoptera (stoneflies) and Tricoptera (caddisflies) and the index corresponds to their percentage in the stream. EPT benthos will disappear in areas of poor water quality, organic enrichment, low oxygen, and high metal levels.

I recently tested this in several ad hoc field trips I made with my naturalist friend Merridy Cox along the Credit River in Ontario. We started our explorations with the lower Credit River watershed, located in the urban setting of Mississauga, Ontario. We sampled the river and a few small tributaries in Riverwood Park, a few kilometres from where the river empties into Lake Ontario.


Originally named “trusting creek” (Missinnihe) by the Mississauga First Nation people, the salmon-bearing Credit River drains some 860 km 2 of Ontario and flows 90 km from its source at Orangeville, over the Niagara Escarpment, through several suburbs, and into Lake Ontario at Port Credit.

Great efforts have been made to restore and maintain the health of the Credit River and its watershed, mostly through the work of the Credit Valley Conservation Authority, together with the provincial and various municipal governments. While the water quality of the lower river is considered generally fair to poor, the river is partially saved by its gradient and turbulent flow. The length of the Credit River, up to very close to its mouth, rushes with the sound of a great storm. It tumbles and gurgles over rocks, capturing oxygen from the air; it scours gravel beds and cuts swirling eddies and creates undercut banks for foraging fish. The habitat is complex and life thrives here. Green algae cling to smooth boulders as water shears over them into pools of bubbling water. Water striders skate on the water surface in calmer backwaters. A cursory sampling of rocks in the river revealed a diversity of macro-benthic organisms. I spotted several species of mayfly, including rock-clinging Heptagenids (flat-headed mayflies) and the stone-building caddisfly Glossoma, all indicators of well-oxygenated turbulent flowing waters. 


About 500 m from where we had sampled in the Credit River, we investigated a small tributary in the forest that led into the river. The creek obviously drained storm water runoff from the streets above; and, while the water was clear and contained riffles with a good flow, I found no macro-benthos on the rocks. Only blue-green algae populated the shoals. This was not surprising, given that storm water and street runoff generally contain contaminants (e.g., chlorides, heavy metals, organics, and oxygen-depriving materials) that the susceptible EPT organisms can’t tolerate.

What struck me was the deceptive nature of this contamination. Most of us, when we think of polluted water, envision a turbid stagnating watercourse with visible garbage, bubbling with toxic algae. The pollution in this tributary was invisible; so was the life. It reminded me that the face of pollution varies and ranges from the obvious (as with most organic enrichment) to the insidiously subtle (as with heavy metal contamination or acid rain).
Water holds many secrets; some good, some not so good.

Water is an introvert.


All illustrations by Kerste Voute and Nina Munteanu
Photos of Nina by Merridy Cox except one of Nina and swan by John Stewart of Mississauga News.
Photo of Merridy Cox by Nina Munteanu
All shots taken at the Upper Credit River, Ontario.
A version of this post complete with references is available at Nina Munteanu's website at this link.


Our guest blog writer Nina Munteanu is a Canadian ecologist / limnologist and novelist. She currently lives in Toronto where she teaches at the University of Toronto and George Brown College. Her non-fiction book “Water Is…” was selected by Margaret Atwood in the New York Times ‘Year in Reading’ and was chosen as the 2017 Summer Read by Water Canada. Her novel “A Diary in the Age of Water” will be released by Inanna Publications in 2020.

3 May 2019

The Surprising Truth About a 100-Year Flood

The surprising thing about 100-year events is that they can happen year after year, not just once every 100 years. That's because the term 100-year event is about chance (probability), not a schedule. It’s a statistical term that means a 100-year event has a 1 in 100 chance of happening each year.

It's One in a Hundred, Every Year

Think about flipping a coin. There's a 50/50 chance of getting heads each time you flip the coin. But you might actually get heads three times in a row. Or 50 times!
Each year, a river may flood or not. The chance of it flooding to a certain height is 1 in 100, or 1%. But the river may have flooded that high three years in a row. Or more!

Thousand Year Event 

Up on the Rouge River in Quebec, just north of the Ottawa River, there is so much flooding right now that it's a 1000-year event. Such a high water level is 10 times less likely to happen than a 100-year flood. Each year on the Rouge River, there is a 1 in 1000 chance that the water will rise this high — a 0.1% chance of it happening.

Figuring Out the Chances

How do we figure out the chances of an event happening? Meteorologists (weather scientists) need at least 10 years of data to math out the chances. The more data they have (say, 30 years’ worth, for example) the more accurate their calculations are. As climate change brings us more and more wacky weather, they’ll have to keep recalculating the chances. What was once a 1000-year event may now be 10 times more likely to happen. New calculations will tell us; and they’ll have to keep redoing those calculations as the data changes.

Not Just for Flooding

The terms 100-year event or 1000-year event can apply to anything: storms, cleaning you room, or having chocolate cake for dinner in the bathtub. Though that last thing might be a 1-millennium event, maybe you can make it happen this year and next.



Want to learn more? There’s a thorough but a bit complex explanation on the USGS (“geological service” that studies our planet) website.

Image by Pete Linforth from Pixabay
Story by Adrienne Montgomerie 

26 Apr 2019

Dressing for Science

The usual picture of a scientist shows someone in a long white coat, working in a lab. And indeed, that's a very practical idea for science clothing - for some scientists. For other scientists working in the field, it might be more appropriate to wear insulated coveralls in cold weather, or a neoprene wetsuit when diving under water. And what about when scientists are presenting their research at a university or conference? Some scientists dress like gentlemen in suits, but what is the option for a scientist who dresses like a lady?

Here's one option, worn by Dr Mary Phillips. She has just defended her PhD, and posted on Twitter a charming photo of herself wearing a dress that honours her studies in brain science. The dressmaker is Shenova, and this link shows 42 of their dresses designed with images about science.

Got a conference coming up where you're presenting your paper on DNA? There's a dress with a striking image of DNA's double helix spiral. Want to show your support for your sister the rocket scientist with a nice dress, to wear at holidays and family events? There are lots of places making dresses, or shirts, or men's neckties to showcase images from science. Other websites such as Litographs make custom shirts and scarves and blankets too, printed with words. Those would be particularly interesting for researchers in history and library science.

It sounds frivolous to speak of pretty dresses when there are serious scientists doing important work. But it is also important for people to look and feel good when they are doing that important work. Some people are still adjusting to the idea of women working in the sciences at all. It doesn't hurt for a woman to wear a scarf printed with every word of her thesis, or for a proud parent or grandchild to wear a shirt celebrating their family's first scientist.

19 Apr 2019

"Snowflake" Bentley and the Sound of Snow


We’ve just had the coldest, snowiest winter in a long time. A great opportunity to look at some of the science (and beauty) of snow. 
We’ve all heard that no two snowflakes are alike. The discoverer of this factoid was an unlikely candidate. Wilson Bentley, “The Snowflake Man”, was a self-educated farmer who adapted a microscope to a camera and pioneered microphotography. His photographs of snow crystals attracted world-wide attention. He photographed over 5,000 snowflakes – no two identical.  

Wilson Bentley with his bellows camera.

More Bentley photographs of snowflakes

Many, but not all snowflakes look like these six pointed stars. There are many other forms. 

Professor Ken Libbrecht of Caltech (California Institute of Technology) could claim to be the modern “Snowflake Man”.
 
The diagram below from Professor Libbrecht's website shows the many forms of snow crystals and how different ones are likely to form at different temperatures. 

  
Most crystals are six-sided because of the geometry of the water molecule, with two hydrogen atoms bonded to an oxygen atom. Any two snowflakes in nature have experienced different paths on their journey to the ground, so are different from each other. But the six sides, or arms, are almost identical to each other because all six sides are subjected to almost identical atmospheric conditions in their path down to the ground. Dr. Libbrecht has grown pairs of snowflakes in his lab, subjecting them to the same conditions. And, sure enough, virtually identical ‘twin’ snowflakes are created. Go to the link below and click on "Growing Twin Snowflakes" to see some spectacular videos showing the crystals growing side by side. 


This winter we had lots of opportunities to walk on squeaky snow. If you live in a cold snowy region you know what I’m writing about. If you don’t: walking on snow is very quiet unless the temperature is quite low, and then you hear a distinctive squeak when you tread on it. So what is it that makes the noise?
Oddly, for such a common phenomenon, there isn’t a single agreed-upon explanation. Or perhaps not so oddly. As one scientist observed on the subject “They don’t give out Nobels for explaining why snow squeaks”.

There is general agreement that snow squeaks at temperatures of -14°C and below, and not above that temperature.

The most likely explanation is that the squeaking is made by the breaking of snow crystals as they are forced into each other. There’s less agreement on why the snow is silent above that temperature.

 One common explanation is that it’s the pressure of your foot. Increasing pressure lowers the melting point of ice. So at temperatures from 0°C to -14°C enough of the ice in the snow crystals will melt and they’ll slide past each other quietly. One problem with this explanation: pressure doesn’t change the melting point all that much; not enough to melt ice at -14°C.

A more likely explanation is this: the surface of ice is always covered by a layer of water. The colder the temperature, the thinner the layer. At -14°C it’s only one or two molecules thick. When the temperature is higher than that the crystals are lubricated by the water and slide quietly past each other as they compress.

Michael Faraday (most famous for his work on magnetism and electrochemistry) first suggested in the 1850’s that this layer of liquid exists. Scientists have subsequently confirmed it. 
Mr. Michael Faraday (he turned down a knighthood, preferring to remain “plain Mr. Faraday to the end”) at the age of about 70. He was self-educated, initially through reading books during his apprenticeship as a bookbinder and bookseller.


This layer of water is also the explanation of why ice skates glide. For more on that, look (again?) at my blog entry in February of 2017 on the subject.

And the best news about all of this is that Spring is here and we won't be hearing squeaking snow for many months.