As we get closer and closer to the end of  the year, we wanted to remind you again   that we have 2023 Microcosmos calendars  available at complexlycalendars.com.

They’re filled with beautiful photos taken by our  Master of Microscopes James Weiss, and each page   has information about the organism on display,  so you know what you’re looking at each month. So, if you’d like to have beautiful microbes on  your wall all throughout 2023, make sure to head   over to complexlycalendars.com  and pick yours up today.

Sometimes our journey through the microcosmos  feels like an expedition, a voyage filled with   deep dives into the masses of organisms  basking under the glow of our microscope. But at other times, this journey feels  like one big game of hide and seek—one that   microbes have been winning in part because for  millennia, we didn’t even know we were playing. Microbes had managed the ultimate   trick of being ubiquitous and yet  completely hidden from our view.

Thanks to the microscope, we’ve managed  to level the playing field a bit,   rendering them and their world visible. And with patience, James—our master of  microscopes—has become pretty adept at   finding microbes in all sorts of unique locations. In fact, it feels almost like the tides  have shifted in this game of hide and seek,   as if it’s impossible for microbes  to truly hide from us anymore.

When we peer through the microscope, it seems  like we should always be finding something. So what does it mean when you don’t find anything. When you gather your samples and excitedly prepare   them for the microscope, only to find a landscape  lacking in the life you expected to find?

That’s the question that James faced  recently after receiving samples from   a very interesting place: the  bottom of a Norwegian fjord. The researchers who sent James the samples are  studying the jellyfish that live in the fjords. But of course, the organisms he was interested  in were on the much smaller side of things.

Fjords are the result of ancient glaciers that  carved out valleys and filled them with water. The water in fjords can run very deep,  sometimes on the order of thousands of meters. And the steep cliffs that run  along the sides add to the sense   that you are suspended in the middle of  a world that is immense compared to you.

As small as we are compared to these depths  and heights, there is a tinier world buried   in all this—one that James was excited to  see when he received around 30 tubes of   sediment samples gathered from depths ranging  from 50 meters to a crushing 1300 meters. But when James opened the first tube, he  had to contend with something unexpected:   there was no water in the sediment. And when he went to dig into the samples,   they were relatively barren, with  only a few organisms appearing.

This might not surprise you. After all, these are cold, dark waters,   conditions that should make it hard for  organisms to survive, let alone thrive. Yet here we are, talking about fjords, and  there are several minutes left in this video.

So surely James found something, right? Yes, yes he did. This is our tour through the depths  of a fjord, told in microbes.

Let’s begin with the first 200 meters of the  fjord, the area called the “sunlight” zone. As you might guess from that name, this is  an area with light, making it the ideal zone   for organisms that rely on sunlight to drive  photosynthesis, like the beautiful diatoms. In the Arctic fjords of Svalbard,   these surface waters are usually shaped  by meltwater that comes from glaciers,   as well as runoff from land, making them lower  in salinity compared to the water beneath them.

As you dive deeper, you can see some of the  remains from organisms that prefer those upper   waters—like these frustules that came from  sediment samples taken at 322 meters deep,   placing them in the area  called the “twilight” zone. This region starts at around 200  meters deep and goes down to around   1000 meters deep, and while some photons  are able to penetrate these waters,   they are not enough to guarantee the  survival of photosynthetic organisms. But that doesn’t mean other creatures can’t  find a way to survive, like these foraminifera.

And descending beyond the “twilight” zone takes  you to...yes, you guessed it, the “midnight” zone. There is no light here, just dark and  cold waters that, at least in Svalbard,   accumulate salt released by sea ice. Again, we find some of the frustules left behind  by diatoms that lived in the sunlight zone.

But we also find more unusual  sights. Like this...thing,   which we think is a tube built by a tubeworm. Running almost a centimeter in length,   the tube was assembled from bits and pieces  of sponge spicules and foraminifera shells.

It’s like a collage crafted  out of other fjord microbes,   telling us more about what  else lived in those waters. It’s fascinating, but not surprising, to find the   populations of microbes changing  as you dive deeper into the water. After all, microbial communities  are shaped by light, temperature,   salinity, and other factors in  all sorts of bodies of water,   whether we’re talking about a  fountain, a puddle, a pond, or a fjord.

We all have preferences for the types  of conditions we want to live in,   and microbes are no different. With that said, there was one creature that  we seemed to observe at every depth of water. In fact, it was often the only  living thing James could find.

Can you guess what it is? It is none other than the nematode! And  perhaps that should not be so surprising.

They are, after all, one of the most  abundant organisms on the planet. And interestingly, the nematodes that  James found from the deeper parts of   the sea had little structures in their  bodies that looked like oil deposits,   though we’re not exactly sure what they  are or what their function might be. Perhaps today we’ve managed a few small  victories in this ongoing game of hide and seek.

But there are connotations to these games that  extend beyond just simple curiosity and joy. The microbes that live in these fjords  are part of a complex ecosystem. They cycle elements like carbon, sulfur, and  iron, and they serve as food for other creatures.

So as glaciers retreat due to climate change,   these communities will have to  contend with a shifting landscape. The way water circulates  through the fjord could change,   bringing different nutrients to the surface  or lifting sediment that blocks more light. Or it may bring some other complication for  these microbes that we can’t yet anticipate.

Scientists are seeking out and studying the  microbial communities in fjords so they can   better understand what these changes will look  like, to decipher what survival and adaptation   looks like at the microbial scale and how  that translates to the world we experience. Because microbes will survive. They’ve survived plenty of extinctions  already, adapting to the new worlds   that arise after and shaping them for  the evolving forms that join them.

Thank you for coming on this journey with us as  we explore the unseen world that surrounds us. And speaking of surviving, the reason  this channel can survive is thanks to   the people you’re seeing on the screen right now. These are some of our Patreon patrons, the people  who have decided to directly support this channel   over at patreon.com/journeytomicro, and we  thank them so much for their continued support.

If you want to see more from  our master of microscopes,   James Weiss, and why wouldn’t you,  check out Jam & Germs on Instagram,   and if you want to see more from us, there is  always a subscribe button somewhere nearby.