Past Passenger Pigeon

Ectopistes migratorius (Linnaeus, 1766) – passenger pigeon (extinct) (mount, public display, Field Museum of Natural History, Chicago, Ilinois, USA).
James St. John (2011) CC BY 2.0 via Wikimedia Commons

We have a passenger pigeon at work. Well, technically it is a stuffed passenger pigeon, preserved in a glass case with other taxidermied bird specimens, in one of our classroom spaces. A plaque, “Gift of So and So, 1985,” discreetly emblazons a corner of the case. The birds are a bit dusty and faded, the passenger pigeon itself has bluish gray feathers with pinkish breast, a shape familiar from the mourning doves and urban pigeons we see around town.

Since last passenger pigeon died in captivity in 1914, I know at least *one* of the birds is over 100 years old, not sure about the others. However, the stuffed passenger pigeon is unique among its preserved fellow specimens of North American birds: Its species is extinct.

I vaguely remember learning about extinction as a kid, because…DINOSAURS. (Were they particularly smelly, dinosaurs? Stink-ed? Was that why they all disappeared?)

A life-sized Stegosaurus model in the Third Planet exhibit at the Milwaukee Public Museum by Evan Howard (2016) CC BY-SA 2.0, via Wikimedia Commons

The spine plates on the stegosaurus model at the Milwaukee Public Museum reminded child-me of the discarded leaves of beloved steamed artichokes (“Look, Ma! Dinosaur peels!”) (Aside: Man, I was a weird kid.)

The poor stuffed passenger pigeon is a kind of species memento mori. “Remember, humans. Your kind shall also eventually perish from the Earth.” Species extinction (hopefully after a good run of a few million years) is a natural part of the evolutionary process. All the cool geological time divisions (Permian, Triassic, Jurassic, etc) are named for observed changes in the fossil species that appear in their rock layers.

But it’s hard not to feel the dusty glass-eyed gaze of the stuffed passenger pigeon as an accusation. Unlike the dinosaurs (who were ultimately doomed by a combination of massive volcanic eruptions, asteroid strike and climate disruption), our modern extinctions can be traced to human destruction of these species’ habitats and populations.

In the New York Times opinion section, philosophy professor Todd May wonders if human extinction would be such a tragedy after all? On the surface, there is a certain poetic justice about it: a) Humans are responsible for other species’ extinction and b) Our wanton destruction of ecosystems only seems to hasten our own species’ demise.

The bulk of the essay hinges on the definition of tragedy (as in Shakespeare), with humanity as the Tragic Hero: “It is humanity that is committing a wrong, a wrong whose elimination would likely require the elimination of the species, but with whom we might be sympathetic nonetheless.”

Poetic justice aside, there is something that is deeply depressing about arguing that (imminent )human extinction is potentially a good thing.
When thinking about the extinction of charismatic megafauna, or rare plants, or even bacteria, we humans have created reasons for why we should save endangered species. These boil down to “Diverse forms of living organisms are valuable to humans. By saving them, we benefit ourselves.” Yet, it doesn’t really answer “What is the inherent value of species? What is the inherent value of humanity?”

On a personal level, everyone I know and love (and even those I don’t) are part of this human planetary experiment. It’s one thing to wax poetic about the romance of extinction on geological time scales. As a human on a human time scale, this awareness of our species’ complicity in other extinctions (and potentially our own) is sad and terrifying. Were the dinosaurs aware their time was coming to an end? Their species extinctions took thousands to millions of years. Were the photosynthetic cyanobacteria of the Paleoproterozoic Oxygenation Event aware their exhalations were rusting the whole planet? Maybe our unique awareness is the guilt we are trying to assuage by grimly examining our own end.

Ambivalently applauding the extinction of humanity is provocative (and cynically satisfying). Yet I think it’s still a fringe philosophical position within the scientific community. Most environmental advocates are firmly in the “Campaign to Save the Humans” camp (with apologies to the late Douglas Adams & the intergalactic dolphins).
Concern for how issues like climate change and persistent environmental endocrine disruptors aren’t theoretical, but directly linked to humanity’s future survival.

Tangents:

R. Alexander Pyron on Protecting Homo Sapiens in the Washington Post.

Nathan J. Robinson Against Human Extinction in Current Affairs.

Extinct Mammals of the Pleistocene at Twilight Beasts

A New History of Life by Peter Ward & Joe Kirschvink (2015)

That spider is my roommate!

House spider – Tegenaria duellica by richard pigott (2011) CC BY-SA 2.0 on Flickr https://flic.kr/p/9uBtdd

I’ve noticed this piece from March 2017 making the rounds on social media this week: If spiders worked together, they could eat all humans in a year. The hyperbolic headline plus a winsome picture of googly-eyed jumping spider clearly induce frissons of revulsion (and clicks!) in many human readers.

Fellow humans, we do not need to worry about the arachnid uprising just yet! 1)Compared to humans, spiders are tiny and fragile *AND* 2)They are not that organized.

The point was that spiders are worthy of human consideration and respect because of their huge effect on biomass (i.e. consumption of insects). For tiny, albeit numerous, creatures, they have a significant effect on our ecosystems.

One of the challenges I encounter as an environmental educator is how to teach respect (also: curiosity, love, awe) for the natural world. This includes the slimy, the wiggly and the multi-legged denizens of our planet. I have encountered humans who are genuinely phobic of arthropods, as well as those who gleefully enjoy crushing them. The goal of nature interpretation is helping participants forge a positive emotional connection to a place and to the organisms that live there. Especially with younger friends, I like to think of it as cultivating empathy for other living beings.

Working in Jewish camp & outdoor settings, we would often teach the midrash of David and the Spider. In the story, a tiny spider builds her web across the mouth of a cave where David is hiding from his pursuers, shielding him from detection. For the rest of his days, as the King of Israel, David declared none should harm a spider, for a spider once saved his life.

Did telling this story actually change kids’ attitudes towards small arthropods? My immediate goal was to introduce an emotional connection (the spider saved a humans life!) which would prevent kids from squishing spiders. I’m not sure to what extent we are a) socialized and b) hardwired to react to an unfamiliar being with revulsion, fear and violence.

But it only once you forge an initial emotional connection (“Interesting!” instead of “Ewww!”), that humans can also appreciate the rational reasons (spiders generally won’t hurt you, spiders are helpful to humans by eating insects, spiders are the amazing results of millions of years of evolution) for protecting a spider’s bodily integrity.

When I lead hikes in the woods, I urge participants to stay on the trail (“the part with dirt and rocks”) to avoid stepping on the homes of plants and animals. “This is their home,” I tell them, “and we are just visiting.”

Even when we find spiders in own houses, I think it is important to recognize the following: 1)They were here first and 2) There are a lot more of them than there are of us. And just in case the spiders *are* merely tolerating our presence before a mass arachnid uprising, it was nice knowing you.

Tangents:

Matt Bertone on why spiders are great roommates.

Sleep Assistant by Pleumier on Instagram.

Grandma Fish

On the internet, no one knows you’re a fish. Tiktaalik restoration by Zina Deretsky, National Science Foundation (Courtesy: National Science Foundation) [Public domain], via Wikimedia Commons

As a modern human who lives on the internet, I sometimes feel disconnected from other humans (my family, internet people, people in real life.) Current events make it easy to want to write off the rest of humanity and throw your lot in with forest creatures.

Except the humans and the forest creatures (and fungi, bacteria, and also the abiotic rocks and water) are all inextricably tangled together.

I was recently reading a Scientific American blog post, in which Scott Barry Kaufman explores how a secular belief in oneness affects how people relate to the world around them.
“In general, those who hold a belief in oneness have a more inclusive identity that reflects their sense of connection with other people, nonhuman animals, and aspects of nature that are all thought to be part of the same ‘one thing.

This idea appealed to my ecological sensibility (“Everyone eats! Everyone breathes!”),and spiritual tendencies cultivated as a Jewish environmental educator. Recognizing plants and animals as fellow living organisms, equally worthy of respect, makes me feel less lonely in the world.

Other creatures aren’t just fellow travelers, they’re Family. The PBS Special Your Inner Fish, based on the book by Neil Shubin, traces human anatomical lineage from the first fish (tetrapod) who crawled onto land.

Tiktaalik at Field Museum, Chicago by Eduard Solà (2012) CC BY-SA 3.0 from Wikimedia Commons

The researchers named the fossil specimen “Tiktaalik, a 375 million year old transitional organism somewhere between a fish and an amphibian. Looking at the animations of the ancient bones, I couldn’t help thinking, “Wow, that’s my grandma!”

Though my literal grandmothers (of blessed memory) would be laughing their heads off at the idea, this fish represents an a direct, familial link from humans to the rest of 4 legged creatures.

Maybe this heritage is linked to the frequency which I often feel like a fish out of water. The awkwardness is baked right in by the millions of years of evolution, folks!

And if you want to go waaaaaay back, there’s Great-to-the-nth-degree Grandma LUCA. As our Last Universal Common Ancestor, a probably single-celled organism floating around in Darwin’s “warm little pond.” LUCA is our connection to most other forms of life on the planet, from fungi and bacteria, to spiders and bananas.

Knowing about the theoretical existence of Grandma LUCA and Tiktaalik (along with all the human great-grandmothers I never met) puts on a new perspective on my place as individual human the world. I’m from a long line of survivors, whose fate is bound up with all the other creatures on Earth.
It’s hard to feel lonely with all those ancestral fish at your back.

Tangents:
In a gentle response to the previous post, John Horgan explores how the philosophy of mystical oneness can also be problematic, especially in the context of authoritarian cult leaders and bad acid trips. The self also needs some solid boundaries.)

Ancestors Remembering Grandma

Terrestrial Whales of the Great Lakes

This post is about a carpet sweeper. For information on “Are there Whales in the Great Lakes?” click here.

Humpback whale feeding. Note baleen strainers. Dr. Brandon Southall, NMFS/OPR, from NOAA Photo Library (2010) CC BY SA, on Flickr https://flic.kr/p/8Uonkn

 

Science Friday had an interesting piece on the evolution of whale baleen for filter feeding. Baleen whales use these gigantic “mouth brushes” as sieves to filter out huge quantities of tiny animals (such as krill and plankton) from sea water. In a new study, Carlos Peredo descibes a fossil species of whale that had lost its teeth, but had not grown baleen. Like modern narwhals, this toothless & baleen-less whale probably used suction to eat fish and squid.

Brushes and suction are two strategies that we also use at the nature center for cleaning up crumbs and dirt after programs. Enter “the Blue Whale.”

“The Blue Whale” by PPJ (2018) CC BY SA 2.0

Note: It’s not an actual whale. It is a carpet sweeper (with a picture of a Blue Whale taped to it) that lives in the cleaning closet. A device of rather antique design, it uses a series of bristles and rotating blades to pull particles off of the carpet and into its maw. It does not require electricity, but relies on the muscle-power of the operator. Our site operations director presented the staff with a couple of these contraptions after several vacuuming mishaps resulted in expensive repairs to the vacuum cleaner.

Like a baleen whale filtering krill from water, the brushes and repeated sweeping motions of the operator, gather up tiny particles from the industrial carpet surface. The operator can open up an internal compartment storing the dirt and crumbs, and then can dump the contents into the trash.

Because the resemblance of the sweeper brushes to whale baleen, one of the nature center staff members started playfully referring the carpet sweeper as “The Blue Whale.” (Coincidentally, it is also a lovely shade of navy blue.)

This nickname caught on, and now a critical mass of staff members are how referring to “Blue whaling” the carpet as perfunctory part of daily clean up operation. Understandably, kids and others who hear this name are somewhat confused.

“What do you call it a “Blue Whale?” they ask.

Since we are nature educators, we then launch into a whole long speech about how whales use baleen to filter their food out of the water. Science! Nature!

There is also a fun and unintended side effect of our branding: Kids love using the carpet sweeper. Not only is it extremely satisfying to watch the Blue Whale sweep up goldfish cracker crumbs and dirt clods, it is much more fun to sweep them up yourself. Like Tom Sawyer whitewashing the fence, kids find it irresistible and will wait their turn to use the Blue Whale to clean the carpet.

And now for our tangent:

Are there whales in the Great Lakes?

There are currently (as far as I know) no whales in the Great Lakes. You cannot go whale watching on any of the Great Lakes. There are no terrestrial (land-dwelling) whales in land surrounding the Great Lakes (with the exception of the aforementioned population of carpet sweepers.) For various reasons, saltwater-adapted marine mammals don’t seem to do very well for long periods in freshwater. Or on land.

The last time there may have been baleen whales living in the Great Lakes Region (albeit not exactly the Great Lakes) was about 13,000 years ago at the end of the last ice age. The Champlain Sea was a temporary inlet of the Atlantic Ocean (saltwater). Fossils of whales have been found here, in what are now terrestrial (land) habitats.

Fatbergs of Chanukkah

Latkes cooling on paper towel (to blot excess oil) by PPJ (2018) CC BY-SA 2.0.

Disclaimer: This is not a post about delicious fried foods.  No, dear reader, this is a post that is kind of gross and you may not want to read while you’re eating.   Consider yourself forewarned.

I have a public service announcement for home cooks out there who might be frying up some latkes or sufganiyot in celebration of the Jewish Festival of Lights.  For the love of all that is holy (and for your local sewer workers), please do not pour quantities of used cooking oil down your kitchen sink drain.

Don’t pour the oil down the drain. Latkes frying on stove by PPJ (2018) CC BY-SA 2.0

Fats, oils and greases (collectively known the waste water world as “FOG”) contribute to the formation of a sewer-clogging menace known as “Fatbergs.”  Fatbergs can accumulate when FOG forms solid masses akin to icebergs that block the flow of wastewater through pipes. Famous fatbergs of recent memory have been documented in the London (UK) sewer system.  A piece of the Whitechapel fatberg is on display at the Museum of London.

But fatbergs happens in a lot of places. In Baltimore MD, a September 2017 fatberg clogged the sewer and caused a million gallons of raw sewage to spill into Jones Falls. Workers in Metro Detroit excavated a fatberg from a sewer in Macomb County in September 2018, at a cost to taxpayers of about $100,000.

Fatbergs are not just gigantic congealed blobs of FOG. The fat undergoes saponification in the presence of calcium ions in the sewer.  In effect, this is same process as mixing fat and an alkaline substance to make soap.  These huge chunks of “soap” clump together with undissolved wet-wipes (and other flushed sanitary products) to form a fatberg. Note: Generally, even if product claims it is “flushable,” it’s better to put it in the trash.

So what can the average home fry-cook do to prevent creating a sewer catastrophe?   If you’re making a lot of fried stuff and the oil is still in pretty good shape, you can strain the oil and reuse it.   Some communities have grease recycling to turn used cooking oil into biodiesel.  (Restaurants usually contract with a specialized grease recycling company to haul off their used frying grease.)  The Recycle Ann Arbor Drop Off Center accepts up to 5 gallons of  used vegetable oil. 

However, most of the time, I just wait for the oil to cool.  Then, I pour it into a lidded jar.  When the jar is full, I dispose of it in the trash.   I also try to wipe out extra-oily kitchen items with a paper towel prior to washing the dishes in the sink.

As for the fatbergs, I’m not sure what fate awaits them once they are scraped out of the sewers.  Except for the piece that ended up in the Museum of London, I would imagine that most end up in landfills.  A research team at University of British Columbia is investigating how to break down fatbergs in a biodigester to make to fuel .

Until then, give some love to your public works department: Don’t pour oil down the drain. Don’t flush “flushable wipes.”   Don’t feed the fatbergs!

The Lettuce, the Phage and the Microbe

 

Rod-shaped E. coli bacteria nestle inside a minute pore in the leaf called a stoma. E. coli bacteria on lettuce by AgriLife Today (2010) CC BY-NC-ND 2.0, on Flickr
https://flic.kr/p/8XNG9g

In the days before the Thanksgiving, the Centers for Disease Control in Atlanta released a stark warning: Don’t eat the Romaine Lettuce. The agency was investigating a a multi-state outbreak of a strain of bacteria called
Escherichia coli O157:H7, which in addition to causing diarrhea and other unpleasant gastrointestinal symptoms, can also cause acute kidney failure and death.

The suspected carrier of this virulent microbe: Romaine Lettuce.

The Suspect! Romaine Lettuce by Rainer Zenz (2006) CC-BY-SA-3.0 from Wikimedia Commons

The internet has been awash in memes highlighting the lethality of poor Romaine lettuce, which is normally lauded for its tastiness in salads and nutrition content. But don’t just blame it on Romaine!

This is actually a interesting ecological saga of microbial romance, ruminant guts, and watershed management intersecting with our salad plates.

Let’s start with E. coli.

Colorized scanning electron micrograph of Escherichia coli, by NIAID (2013) CC By-2.0 on Flickr
https://flic.kr/p/rg1p9H

E. coli is a type of bacteria that normally lives in the intestines of humans and animals. Most E. coli strains are harmless, and actually provide a protective role in the intestine by preventing disease-causing bacteria from moving in. They also help make Vitamin K. Scientists love using E. coli an a model bacteria in the lab. It is easy to feed and grow!

On an environmental scale, E. coli can get transferred from its home in the intestines to the larger world via … poop.

So how do the bacteria make it from poop into another intestinal home? Water! Humans came up with this ingenious idea of making our poop go away by sending it into flowing water.

Bye! Wolfmann (2018) CC BY-SA 4.0, from Wikimedia Commons

We have mitigated the E. coli transfer somewhat by treating our sewage (which I realize is just a fancy word for poop-water) before dumping it out into rivers and lakes. However, leaky septic systems and intense storm overflow events may cause sewage to bypass the treatment process and end up in the water anyway. Animal poop lying around on the ground (or in big lagoons on a cattle feedlot) may get washed into waterways by rain.

Belleville Lake beach closed due to high bacteria levels (E. coli) in the water. Local sources of E. coli bacteria include leaky septic systems and storm runoff containing animal poop. by PPJ (2018) CC BY SA 2.0.

Some of this E. coli-laden water makes it to a farm irrigation system, where it waters the the lettuce. And leaves behind a nice film of E. coli bacteria in search of a new intestine to live in.

Most E. coli versions aren’t dangerous. This water-borne bacteria becomes a problem when the kinds of E. coli venturing forth into the water include less-benign, disease-causing versions. These pathogenic strains secrete toxins that can damage tissue cells in the human body. Scientist can track these variants by their serotype designations (i.e. O157:H7) that refer to the arrangement of sugar molecules in the E. coli bacterium cell wall.

So where do the toxins come from? For example, E. coli O157:H7 produces a Shiga toxin that damages intestinal cells to cause bloody diarrhea, and potentially even kidney failure by damaging the tiny kidney capillaries with the debris of broken cells. Shiga toxin was first identified in the bacterium Shigella dysenteriae, a pathogen that causes dysentery (severe diarrhea.) Producing bacterial toxins may confer evolutionary advantages over non-toxin mediated infection by increasing the virulence of the bacteria, as well as increasing transmissibility of bacterial particles via diarrhea output.

“You have died of dysentery.” Screenshot from classic Apple II educational computer game, Oregon Trail.

But how did the genes for making Shiga toxin make it from the genome of Shigella into its cousin E. coli?  Through bacteria sharing genes via bacteriophage, or its less sexy name, Transduction.

Bacteriophages (virues that infect bacteria) are often floating around places like intestines where lots of different kinds of bacteria are hanging out.

Just going through a phage.  Bacteriophage exterior by Adenosine  (2009) CC BY-SA 3.0  from Wikimedia Commons

In this case, a phage may have transferred a snippet of genetic material containing the toxin-coding region from a Shigella spp. bacterium into an E. coli bacterium, granting a previously benign microbe an infectious advantage. (Tangent: Bacteria can also use this process to transfer genes for antibiotic resistance.

Okay, so now that we have a Shiga-toxin producing strain of E. coli, how did it end up on the Romaine lettuce? Are sick humans just pooping indiscriminately all over our lettuce fields (or within the watersheds that flow into irrigation systems?)

Possibly,  however a more likely culprit has a ruminant digestive system and hooves:

Serious, serious cattle by J.C. Burns (2017) CC BY-NC-ND 2.0, on Flickr https://flic.kr/p/UFMCNG

Turns out that cattle (and other ruminants such as deer, goats and sheep) are asymptomatic carriers of the Shiga-toxin producing strains of E. coli. The bacteria do not make the cattle sick, possibly because they lack specific cell receptors the bacteria use to attack blood vessels.  The cattle are a living reservoirs for these E. coli strains, as well as contributing to literal reservoirs for the bacteria in the form of waste retaining ponds full of cattle poop. That poop-carrying water is just a rainstorm and a watershed away from making its way to the lettuce fields.  Voila, you’ve got an epidemic of foodborne illness!

While it’s tempting to reduce the media narrative to “Romaine Lettuce is now deadly,” I think it’s much more interesting to look at the interconnections between all of the players in this story (The Cattle, the Poop, the watersheds, the E. Coli and the bacteriophage). The science is much weirder than you might imagine.

Huron River Blues: Part II

Harmful Algae Blooms (HAB)

aka “Just because it’s natural doesn’t mean it’s good for you.”

For Huron River Blues: Part I  PFAS Contamination, click here

Harmful Algae Bloom, Photo Credit: Jeff Reutter (2013) CC BY-NC 2.0. Ohio Sea Grant, on Flickr url=https://flic.kr/p/fL6zbo

It’s not just any old green slime floating on your freshwater lake. Those are Harmful Algal Blooms (HAB) that made an toxic appearance on Ford and Belleville Lakes this past summer. It’s an ancient organism gobbling a breakfast buffet of phosphorus and nitrogen delivered to it in bed. The lake bed, that is.

Sign at Belleville Lake near French Landing. (2018) by PPJ.

Harmful Algal Blooms (HAB) occur when algae, the tiny single-celled photosynthetic organisms that naturally occur in aquatic habitats, grow in rapid “blooms” when nutrients wash off the land into their watershed. Side effects include a carpet of slime, production of toxins harmful to humans and other animals, and depletion of dissolved oxygen in the water.

Anabaena flos-aquae (light micrograph) (2011) CC BY-NC-ND 2.0 by FWC Fish and Wildlife Research Institute on Flickr https://flic.kr/p/9Rg5kY

The “Algae” in HAB is kind of catch-all term for wide variety of organisms that scientists keep re-classifying. While it is helpful to think of these as “tiny plants that live in the water,” these organisms can include cyanobacteria (aka blue-green algae,) phytoplankton and dinoflagellates. There is a lot of overlap here, none of these are actually “plants,” even though some can make their own food using the sun. Some of their cells have nuclei, some don’t.

HABs Near Boat Dock by NOAA Great Lakes Environmental Research Laborator, on Flickr https://flic.kr/p/9VdBL6

These algae are naturally around in freshwater bodies of water.   Human use of fertilizers that wash off of agricultural fields and lawns contribute an influx of nitrogen and phosphorus into the water. With lots of available food and warmer temperatures, the algae continue to grow into visible mats of slime.

The HABs (which I like to think of as “algae parties”) can release a variety of cyanotoxins such as microcystin into the water.   These compounds can dangerous to humans and animals drinking or swimming in the water.

When the algal blooms die, they sink to the bottom of the lake.   Other bacteria decomposing the dead algae gobble oxygen from the water, creating “dead zones” with very low dissolved oxygen.

Ford and Belleville Lakes are human-made reservoirs of the Huron River.  There are susceptible to HAB’s because the are 1) relatively shallow and can warm up quickly and 2) are downriver of a lot of lawns (so much tasty phosphorus and nitrogen!) (I should point on that everything that ends up in the Huron River will eventually end up in Lake Erie, which has been experiencing its own series of epic HAB events.)

All those lawn inputs are just going to end up in Lake Erie. Emptiness (2011) CC BY NC 2.0 by Beth , on Flickr. https://flic.kr/p/MdXgo

Over the last few years, Ann Arbor and Ypsilanti have enacted ordinances limiting use of phosphorus in fertilizers on lawns. Researchers at University of Michigan also discovered that by manipulating the flow of Huron River water through the dam at Ford Lake could mix more oxygen into the water and reduce the amount of phosphorus released from lake sediment. Less phosphorus release, fewer HABs.

Things had been looking better for Ford and Belleville Lakes in terms of reduced algae bloom slime, until this September. According to the Huron River Watershed Council, warm temperatures and little-to-no rainfall contributed to low water levels in Ford Lake. “The problem this year is that the flow level was too low to keep the dam turbines running AND send enough water through the bottom gates to mix the lake. Ford Lake went anoxic at its deepest levels for a period of time, releasing large amounts of phosphorus from legacy sediment, and this likely led to the HABs in Ford Lake, and then downstream in Belleville Lake.”

With climate change, the Great Lakes region is likely to experience warmer temperatures and more unpredictable precipitation events, leading to an increased potential for HABs.

Woolly Bears’ Picnic

White woolly bear on sunflower leaf by PPJ (2018) CC-BY-SA 2.0

In the children’s song, Teddy Bear’s Picnic, a group of Teddy Bears has a party in the woods when their humans aren’t looking. (When I was 4, I found this song particularly terrifying. Maybe was the idea of toys sneaking off into the woods, or the minor key or the scratchy record it was playing on in my preschool classroom.)

Today, I was pleasantly surprised to find a party of fuzzy caterpillars (colloquially known as “Woolly Bears”) hanging out on the undersides of various plant leaves in the garden.

Brown woolly bear on sunflower leaf by PPJ (2018) CC-By-SA 2.0

reddish brown woolly bear on nasturtium

Cream woolly bear on holy basil by PPJ (2018) CC-BY-SA 2.0

As cute and fuzzy-appearing as they are, I avoided petting them. The spines in the caterpillar fur can sting or cause allergic reactions in humans, which is a pretty useful self-defense mechanism.

I’ve posted photos on iNaturalist to see if I can get more specific id’s, but I suspect these are probably some variety of Tiger Moths (Family
Arctiinae).

In other more terrifying caterpillar news, I also observed a hornworm (Sphinx Moth larva) on my tomato plant being parasitized by brachonid wasp cocoons.

The female wasp lays her eggs inside the hornworm caterpillar. (She also injects some venom and a symbiotic virus that inhibits the caterpillar’s immune response and prevents metamorphosis.) The baby wasp larvae feed inside the caterpillar’s body, then form cocoons on the outside of the caterpillar. It’s like the hornworm caterpillar is the babysitter, who has to house and feed the babies dinner (from its own hemolymph). Of course, when the adult wasps emerge from their cocoons, it usually kills the hornworm.

This is probably has helped my tomato plants, by slowing how much damage to hornworms can do by nibbling. We got a great crop delicious cherry tomatoes. On the other hand, I recognize a certain pathos in the doomed caterpillar.

More about how braconid wasps parasitize Manduca spp. caterpillars.

Past precipitate

It’s been a week since my last post and I’m still thinking about salt.  Salt mines. Road salt. Sea salt. Waking up in the middle of night and drinking several glasses of water because dinner was too salty.   (You also can’t make a batch of lactofermented pickles without some salt.)

All aboard the salt train! Salt in cars on train tracks underground in a Carey Lyons salt mine, By undergrounddarkride CC BY-2.0, via Wikimedia Commons https://commons.wikimedia.org/wiki/File%3ASalt_Cars.jpg

I was disappointed to find out that the salt mines under Detroit are not open to the public for tours.  However,  if you head to Hutchinson, KS (also home to the Kansas
Cosmophere), you can check out the tours at Strataca: The Kansas Underground Salt Museum. These Wellington formation salt deposits are the remnants of another inland sea that once covered part of Kansas 275 million year ago during the Permian Era.

I remember learning in 6th grade social studies that salt was a major trade item in the kingdoms of ancient Africa. Check out this National Geographic video from Taoudenni, Mali of salt mining and transportation, similar to the process that took place hundreds of years ago. The workers cut slabs of salt from the beds, which traders load onto camel caravans to transport across the desert to Timbuktu.

Salt Selling at Mopti Mali by Robin Young (2003) CC By 2.0 via Wikimedia Commons. https://commons.wikimedia.org/wiki/File:Salt_selling_Mopti_Mali.jpg

The Taoudenni salt deposits are relatively recent Holocene (geologically speaking). Lakes covered this area about 9000-4000 years ago. As the climate changed, the lakes eventually evaporated, leaving salt deposits behind.

To produce sea salt, harvestersevaporate seawater in shallow ponds. (Technically, mined salt is also sea salt, from sea water that evaporated a really long time ago.) Various dissolved salts precipitate (crystallize) out of seawater at different rates.

Satellite photo of San Francisco Bay salt ponds, taken in 2002 {{PD-USGov-NASA}} via Wikimedia Commons. https://commons.wikimedia.org/wiki/File:San_Francisco_Bay_Salt_ponds_2002.jpg

One of the challenges of producing modern sea salt is the presence of microplastics left behind by evaporating seawater. Karami et al (2017) tested 17 commercially produced sea salts from 8 countries for microplastic particles. These tiny bits of plastic wash out in our laundry wastewater, or photodegrade from larger pieces of plastic floating around in the ocean. Eventually, ocean circulation brings those tiny plastic bits to even remote locations (like the very bottom of the ocean). From the report, “Due to their low density and slow degradation, plastics are becoming the chief cross-border contaminant that often travels far from their original source. Hence, [microplastics] found in the salt samples of one country could have been produced by another country thousands of miles away. ”

For more about microplastics pollution, check out my posts here and here.

Memories of an Ancient Shallow Sea

Running low on salt, by A. Drauglis, (2010) CC BY-SA 2.0 on Flickr.
https://flic.kr/p/7CazLC

This morning, I woke up to the rumble of salt trucks and snow plows. Southeast Michigan is experiencing the first significant snowfall of the season this week. The mood is varied (depending on who you ask) with emotions of delight, annoyance and resigned acceptance (sometimes all mixed together).

While the kid part of my personality checks the school closings for a snow day first thing (810 today in Metro Detroit!), the grownup part (with the driver’s license) is very grateful for my car’s snow tires, the snow removal crews and copious amounts of rock salt sprinkled on the roads. Salt, when added to the wintry roads, keeps the slush and melted snow from re-freezing by depressing the freezing point of water. When salt molecules dissolve in a film of liquid water on top of ice, these dissolved substances alter the way that water molecules can line up to freeze. It takes a lower temperature to freeze water with stuff dissolved in it.

Much of the rock salt used this area is actually mined from salt deposits 1100 feet beneath Metro Detroit. (For more about the history and mining process of the Detroit Salt mines check out The Detroit Salt Co. page.)

These salt layers are what remains of a shallow saltwater sea that once covered this area around 410 million years ago. This ancient “Great Lakes region” (which is a little confusing, because the Great Lakes wouldn’t form for another 400 million plus years), was located near the equator. Coral reefs allowed some water in, but limited exchange with the larger ocean. The seawater got saltier and saltier as the water evaporated in this hot climate.

Maybe the salty sea looked something like this. Halite deposits on the western Dead Sea coast, Israel. by Mark A. Wilson (2012) CC BY-SA 3.0 , via Wikimedia Commons. https://commons.wikimedia.org/wiki/File%3ADead_Sea_Halite_View_031712.jpg

Eventually, the salt (and other minerals) would precipitate in layers from the super salty water that sank to the sea bottom. By the end of the Silurian period (390 mya), this inland sea completely dried up, leaving only the salt deposits behind. (I highly recommend checking out MSU Prof. Randall J. Schaetzl’s online resources about Great Lakes geology.)

I like to think about how the salt spread on the local roads (even though it contributes to potholes, cars rusting and water pollution) is a connection in deep time to sunny days on an ancient sea. Right here, in this place (but not this latitude), now and 400 million years ago.