"The Capelin are Rolling"

"The capelin are rolling". That's what the lady in the fluorescent vest answered when we asked her what all the excitement was about. She was preventing cars from entering the already-full parking lot at the cove. Like a hundred others, I had parked along the highway and walked back to the cove.

I had an idea of what capelin were: little silvery fish. Ten days earlier on our trip to Newfoundland, the skipper of our tour boat to Witless Bay had said "You folks are lucky. We're going to see whales. There were no whales here until a few days ago when the capelin showed up and the whales follow and feed on the capelin". But I had no idea what "rolling" meant.

It turns out that "rolling" means that millions of capelin come in to shore to spawn on the beaches. This happens only once a year for a few days. And the locals come in to scoop up the capelin in nets or any handy container. It's a happening scene. You only have to wade into the ocean up to your ankles to scoop up buckets of fish. People of all ages were happily gathering dinner and walking off with shopping bags full of fish. It's quite a defining moment for local culture.

The capelin are rolling at Middle Cove, just north of St. John's

Dead capelin littering the beach

Anyone can scoop up capelin with a net

Buckets and shopping bags full of capelin

But the capelin are significant for more than a fascinating local cultural event. Capelin feed on plankton.  Other animals, including whales, puffins and cod, feed on capelin. So capelin are a critical link in the food chain. And capelin stocks have been declining. In 2018 the Department of Fisheries and Oceans (DFO) announced a 70% decline in capelin population. The population is only 25% of what it was in 2014, and that was much smaller than before a population crash in the 1990's!  My first thought at seeing people scooping up the fish was that this must be a threat to the capelin stocks.

But no: most of the fish die anyway right after spawning, so harvesting them then does little to the population. And, anyway, people aren't walking off with more than a few tonnes of fish in their buckets and shopping bags. Somewhat more significant is the commercial catch. Surprisingly, the DFO increased the commercial fishing quota from 17,500 tonnes in 2018 to 18,600 in 2019.

Hard to believe from this picture, but commercial fishing is a minor predator

Why? The scientists at DFO believe that the decline is due more to environmental factors than to fishing, and consider the fishing to be a very minor factor in influencing the population size. They estimate that fin fish alone eat a million tonnes of capelin (and whales and seabirds are also significant predators).

The World Wildlife Fund disagrees with DFO and calls the increase in fishing quotas "short-sighted". Who's correct? It's not clear - there are so many factors involved that accurate forecasts of population are impossible. But maybe you should plan a trip to Newfoundland soon if you want to see the capelin rolling.

Fishy Sauce and a Fishy Date

By Claire Eamer

The Garum Shop in the ancient Roman city of Pompeii was a small business that manufactured and sold a fish sauce called garum that Romans adored. The shop went out of business suddenly and permanently in 79 CE when the nearby volcano, Mount Vesuvius, erupted and buried it, the city, and several other communities under metres of volcanic rock and hot ash.

This is the Triclinium or dining room of a wealthy family
in Pompeii. The diners would have reclined on beds while
eating dishes liberally laced with garum. Claire Eamer photo.

In 1960, archaeologists uncovered the Garum Shop for the first time in 1880 years. Buried with it were six large ceramic containers called dolia and several of the large pottery vessels called amphorae used for everything from wine to -- in this case -- fish processing. The dolia contained the remains of garum in several stages of production, and some of the amphorae contained the well-preserved bones of hundreds of tiny fish.

Fishy flavour

Now, historians have known for centuries that the Romans loved garum and ate it in huge quantities. But they didn't know exactly what it was beyond a liquid made from decomposed, fermented fish, fish blood, fish guts, and other fishy bits. Doesn't sound very appealing, does it? But no one knew how appealing it might be because no one had tasted it in the better part of 2000 years.

A street-food booth in Pompeii. The railings are modern, but the rest of the shop
is just as the owner left it almost 2000 years ago. The counters have large ceramic
containers sunk into them to hold the day's offerings, certainly including garum.
Claire Eamer photo.

And we didn't have a decent recipe. Have you ever tried to recreate your mother's perfect chocolate cake icing or your grandmother's perfect butter tarts? (I have.) Even if you have the original recipe and you know exactly how it should taste, it's not easy. So -- no detailed recipe and no idea of what it should taste like made garum a mystery.

In the last few years, however, archaeological science has reached the point where those garum remains are more than a curiosity. Chemists are analyzing them to determine exactly what went into garum and in what quantities. And archaeozoologists are studying the fish bones to figure out what kind of fish were used.

Fishy calendars

The top is gone from this three-legged table, but the marble lion
feet remain. It was a valued antique. An inscription says it once
belonged to Casca Longus, the first to strike Caesar when he was
murdered in the Roman Senate in 44 BCE. Claire Eamer photo. 

That's where the fishy date comes in. For years, the most widely accepted date for the eruption of Mount Vesuvius was August 24, 79 CE. That was based on a letter written by an eye-witness, Pliny the Younger, whose uncle died in the eruption. But Pliny's letter was written 25 years after the event, and the original disappeared long ago. We only know it from translations and copies, and they don't agree on what the Roman date translates to in modern terms.

Back to the fish. Scientists studying fish bones from the Garum Shop determined that they came from a small Mediterranean fish called the common picarel (Spicara smaris) -- and that all the fish examined were 10 to 13 centimetres long, about a year old, and all female. Fish have growth rings in their bones, much like the growth rings of trees, so the scientists could even tell that they died when the water was warmest -- late summer or early autumn. Then they were thrown whole into amphorae and packed with brine and, probably, herbs. They had been in the amphorae from one to three or four weeks when the heavens rained hot ash and buried them.

The August 24 date for the eruption was already in doubt because of other archaeological evidence, and the fish evidence made it even fishier. Large shoals of female-only picarel come close to the shores of southern Italy in late August and September, so that would push the eruption date to mid-October or later.

Fish-free evidence

Huge millstones still sit in the courtyard
of a Pompeii bakery and flour mill.
Claire Eamer photo

Just a year or so ago, an even more definitive piece of evidence for a later date turned up -- a bit of writing scrawled on a wall in charcoal. It's just a date, probably left by a tradesman working on a house, but the date translates to October 17 in our calendar, almost two months after the workman should have died in the eruption. The latest guess is that Vesuvius blew its top about October 24.

So fish and a long-dead tradesman appear to have corrected a fishy historical date. And while we still don't know exactly what garum tasted like, the chemists are busy fishing (sorry -- couldn't resist) for the recipe.

References:
Carannante A. The last garum of Pompeii: Archaeozoological analyses on fish remains from the "garum shop" and related ecological inferences. Int J Osteoarchaeol. 2019;29:377-386.

Pompeii: Vesuvius eruption may have been later than thought. BBC News, 16 October 2018. Located at https://www.bbc.com/news/world-europe-45874858. 

Today's Fun Fungus Walk

Our own Joan Marie Galat is a scholar of all things fungus. And she still knows how to enjoy just finding the odd mushroom here and there while out for a walk in the woods. Here are some photos she shared recently with friends. With compassion for those of us who can find it hard to figure out Latin names for various species of living things, she's captioned these photos in a more informal way.

 "Bite marks?"

"A colony."

 "A super-colony!"

 "Notice the rarely-seen upside-down bottlecap mushroom."

"The funnest of fungi!"

You can also explore the outdoors, including trees, wildlife, and the night sky, through the pages of Joan's books [https://www.joangalat.com/view-books/] . Her comments there are considerably more precise, and very interesting!

Are You Taller Than Your Mother? Was She, Too?

“I hate holidays. Everyone always asks me how tall I am,” my son said, looking down at me. At only 13, he could already reach the top kitchen shelf without a step ladder.

“Well why don’t you ask it back?” I said. “Ask if they’re taller than their mom.”

We got great stories from the aunts and uncles that Christmas. And we discovered a surprising thing: even the shortest of the aunts and uncles were taller than their parents!

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How can kids keep on growing taller than their parents? Where will it end? Will doorways become hobbit holes? Will humans end up being giants!?

By some measures, we are getting taller and taller. By other measures, average height hasn’t changed much since the Stone Age (well over 8000 years ago). Back then, the average European adult (that we have unearthed) was 168 cm tall. That's only 2 cm shorter than today.

Some of the height humans have gained comes from eating better. Nutrition is getting better understood over time, and it has gotten much easier to get a variety of good foods all year ‘round. Kids are also less often, thanks to sanitation and vaccination, so their growth isn't stunted. That makes the biggest difference before age 2, when a body’s pretty much decides how tall it can get.

In the last 200 years, average height has been creeping up. A full 10 cm more for the average adult Earthling in just the last 100 years. (That's confusing, if you remember Stone Age people were only 2 cm shorter than us. But we've only been able to measure about 80 people who lived in the Stone Age.) The data show that this change might be slowing down. The areas on Earth where we find the tallest adults, those people are not gaining height as fast as they used to. In fact, they're practically not getting taller at all. The human body may simply not be able to take in enough nutrients to make us a race of giants.

Even among healthy, well fed people today, adults are a lot of different sizes. Variety is normal; height isn’t a way to know for sure if one person grew up healthy. Genetics has such a big affect on height that where someone is born — their parents’ genetics — makes a bigger difference than their health. 

Sweden is where you'll find the tallest people, and Canadians are only a couple centimetres shorter. Even location differences are not steady: South Asian women have been getting taller much faster than women from anywhere else in the world. 

Women are usually shorter than men. A full smartphone length shorter, on average. This may change too. In some places on Earth, women’s average height is growing faster than men’s. 

Are you going to be taller than your parents? Probably. But the data shows that may be more about them shrinking than the boundless potential for you to be a giant. We'll talk about the incredible shrinking ancestors in another post.