The Daily Bucket is a regular feature of the Backyard Science group. It is a place to note any observations you have made of the world around you. Snails, fish, insects, weather, meteorites, climate, birds and/or flowers. All are worthy additions to the bucket. Please let us know what is going on around you in a comment. Include, as close as is comfortable for you, where you are located.
April 26, 2013
Salish Sea
Pacific Northwest
The ocean has bloomed in the last few days. Millions of single-celled phytoplankton have proliferated in the nutrient-rich cold waters of the Pacific Northwest, photosynthesizing with abandon under the sunny skies we have enjoyed recently. The clear winter water has turned emerald green, dense with life.
I took a sample today to see which populations are blooming. This is what I saw under 40x. Mostly diatoms, one of the main groups of phytoplankton.
The long straight chains are
Lauderia, the spaced beadlike chain are
Thalassiosira, while the curly ones are a species of the gigantic genus
Chaetoceros. I'd estimate about 80% of the phytoplankton in the bay today is made up of these three species of diatoms.
Any to worry about? Not today. While there exist a few species of phytoplankton that are dangerous, like the infamous "red tide" dinoflagellate, producing a nerve toxin which concentrates in the flesh of shellfish, I found no toxic species in this seawater. All this greenery is just good food for the many consumers throughout the marine food web.
And in a global sense, they also remove carbon dioxide from the atmosphere, producing oxygen. Phytoplankton add more oxygen into the atmosphere than all our forests, fields and wetlands combined. Macro-algae, like kelp, are an additional contributor from the ocean.
A seasonal comparison of their activity is revealing. Let's look at two diatom species that were present both today and in a winter sample (I had to look through a lot of that February water, even concentrated by a plankton net, to find any intact phytoplankton at all).
Triceratium, April
Chaetoceros, April
Triceratium, February
Chaetoceros, February
The winter cells have few pigment-filled chloroplasts while the spring cells are greeny gold with them. They have visibly ramped up their production.
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Here are a few more species that got snatched up in my net while they were busily converting the energy of sunlight into carbohydrates, to fuel their prodigious reproduction. Note: I use various filters with the microscope, which give the photos a background color. But the overall color of the water in the bay comes entirely from the phytoplankton themselves, the green and gold pigments you see inside their clear silica shells.
(I wish they were all in focus, but even though the drop of seawater is confined in an invisibly small layer between the slide and coverslip, that layer is still thick at the microscopic level. Imagine looking down into a skyscraper made of clear glass with binoculars - how many floors of the building would be in focus at once?)
Melosira
More below the curly strands.
Odontella
Some phytoplankton can move on their own, which may be a bit surprising. Ecologically phytoplankton ("plant" + "drifters") are analogous to plants, the food producers for life on land. But their three-dimensional water-supported lifestyle allows them more freedom. This is
Bacillaria, whose cells slide past each other visibly.
Bacillaria the next moment
Bacillaria one moment
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Notably, most of the species blooming right now are colonial chains. There's probably a reason for that. Fragillaria is yet another colonial diatom:
Here's a closeup of
Thalassiosira, at 100x. Its individual bead-like cells are connected by filaments that may be too thin to see here:
One of my favorites is this curly species of
Chaetoceros (100x):
You can just barely see the very largest creatures in the path of particle-scattered light below. A patch of sunlight shines through a square hole in the dock above me. The square of pollen-dusted water shows us where the surface is. Below, the mussels and barnacles and such are feasting!
Not all the microscopic life in the water is tiny phytoplankton. Next to the triangular
Licmophora cells is a large gray mass, in this view magnified 100 times. The black dot near the bottom is the eye of a giant creature, bent on gobbling up what it sees as greeny bits of food.
This monstrous creature is Copepod, a member of the zooplankton. We'll look at some zooplankton in another bucket of seawater.
Life proliferates everywhere. What's blooming or preying in your backyard on this late April day? Drop your observations into the Bucket.