Inspired by Anne Jungblut’s public lecture at this year’s British Phycological Society meeting, where she talked about the algal life that thrives in Antarctica (available here), I decided that a mere thirty centimetres of snow was not going to deter me from some pond dipping at a local lake. “I’m going out, I may be some time” I muttered to no-one in particular as I pulled on my boots, filled my pockets with energy bars, and headed into the snow-blasted waste that was County Durham.
Fortunately, my companion on this expedition has a heritage that embraces the nationalities of both Scott and Amundsen, so I knew that I had a 100% chance of getting there and at least 50% chance of returning home. Undaunted, we made our way across snow-covered fields, through a Narnia-esque woodland and finally emerged at the edge of a Cassop Pond which was, perhaps unsurprisingly, frozen over, foiling my efforts to gain a sample by usual means. We tracked cautiously around the margin, never quite sure where solid land was replaced by thin ice, until we found the outflow where there was an exposed channel and some dead read stems. This would have to do as a sampling location so I dug out a sample bottle and plastic bag and pulled on a veterinarian’s disposable glove, designed to be shoved up into the warmth of a cow’s rectum but also a way of keeping your arm dry whilst sampling cold water in the middle of the winter.
This was the moment, of course, when two acquaintances passed by and, recognising us, wanted to know why I was crouched beside a stream of freezing cold water wearing a bright orange veterinarian’s glove and fumbling around amongst decaying reed stems. This, I am fairly sure, does not happen to real Polar explorers. Amidst all the trials and tribulations of life in Antarctica, feeling a bit of a plonker is the least of your worries.
An effective way of collecting the algae off submerged plant leaves and stems is to place them in a plastic bag with a little stream or pond water and give them a vigorous shake. This is what I did with a couple of handfuls of reed stems and the result was a brownish suspension in the bag which I poured into a sample bottle before allowing our inner Amundsen to guide us home. Our return route passed a field of Highland cattle all of whom gazed placidly at me in a way that they almost certainly would not have done had they known that I had a veterinarian’s glove in my bag.
Back home and warmed up, it was time to look at the murky suspension and see what it contained. I’ve visited Cassop a lot over the years (the very first post on this blog, for example, described a visit, also in January) and had a good idea of what algae I might find. Whether the unprepossessing substratum of dead reed leaves or the time of year or a combination, there was not quite the rich diversity I was expecting, but there were a lot of cells of Fragilaira (probably F. tenera) and a few other species too. There were also plenty of tiny Lemna minor plants floating around at this time of year and, as my first ever post showed, these host a number of epiphytic diatoms.
This will be the first of several visits to Cassop pond this year. Last year was the first time in several years that I did not have a regular focus for my posts (see “Reflections from Castle Eden Burn” for an overview of my 2019 explorations). I had originally planned a series of visits to a location which, though easily reachable by car, would fall foul of the current lockdown restrictions. Instead I’m looking at a pond that is walking distance from my house. Maybe that is not such a problem: not everyone is lucky enough to have a National Nature Reserve on their doorstep and I have, in all honesty, not given this pond the attention it deserves over the years.
The richness of aquatic microscopic life in winter has been a recurring theme in this blog over the years but should that richness surprise us? We approach the world of algae with mindsets that could be described as “Angiosperm Supremacists”, basing our assumptions on the entire plant kingdom on how we expect higher plants to respond. Yet, in evolutionary terms, angiosperms are relative newcomers forced to exploit dry land because the best aquatic habitats had already been monopolised by algae. Away from the protection that water’s high specific heat capacity offers a plant, survival in winter depends on being able to divert energy into a range of protective strategies in order to prevent damage due to freezing (see reference below). There are algae that live in and on ice but, for most, the environment beneath the ice offers fewer challenges. Indeed, as most of their grazers are poikilotherms, winter (all other things being equal) is not a bad time to be an alga.
Knight, M.R. & Knight, P.H. (2012). Low temperature perception leading to gene expression and cold tolerance in higher plants. New Phytologist 195: 737-751.
Some other highlights from this week:
Wrote this whilst listening to: John Martyn and, in particular, a 1978 Rock Goes To College set on YouTube that I remember watching when it was first aired. [https://www.youtube.com/watch?v=GYvncpoeV5Q&t=2132s]
Cultural highlights: A great new film called Sylvie’s Love, set in jazz-era New York.
Currently reading: The Science Delusion by Rupert Sheldrake
Culinary highlight: Recipe from The Guardian last weekend: a chocolate and marmalade tart.