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. Rain, sun, wind...insects, birds, flowers...meteorites, rocks...seasonal changes...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. Each note is a record that we can refer to in the future as we try to understand the patterns that are quietly unwinding around us.June 3, 2014
A month ago the waters of the bay near my house were clear, with my sampling net showing nothing but microscopic detritus and a few creatures who manage a living over the winter scavenging such organic debris. This week I saw a promising murkiness in the water. A sample under the microscope shows us why: early populations of plankton have begun to bloom.
These thousands of living golden chains are why the water we see is a golden soup of nutritious energy.
In the marine world, a bloom is the sudden explosive growth of a particular population of microscopic creatures, triggered by sunlight and a nutrient supply. Sometimes these can be dangerous, producing toxins or depleting oxygen in a body of water when massive volumes decompose. HABs (Harmful Algal Blooms) usually occur where excessive nutrients like agricultural fertilizer or sewage are dumped into a small area with poor circulation. I do have reason to think there's anthropogenic nutrient run-off into this bay, from the type and volume of certain kinds of seaweed, but these blooms we're seeing now are entirely expected at this time of year.
More marine life below the golden tangle of algae...
(All photos by me. In Lightbox...click to enlarge)
Right now we have light almost 16 hours a day. Currents and swells are stirring up a winter's accumulation of nutrient-packed detritus. It's a race to convert these resources into life. And the winners are....
...and more specifically, the chain-form diatom species, dividing over and over in one dimension. By far, the most abundant are several species of Chaetocerus, which all have thin hair-like projections (setae) along the sides of the chains that help keep them buoyant. There were also a few Thalassiosira (spaced cells, here's one section of 5). I see three kinds of Chaetocerus in this view, one of which has an intriguing overall spherical arrangement.
These spheres were common. You can see another here, focused on the edges rather than the center. I think this might be Chaetoceros socialis, a widespread and robust species.
Three setae of each cell are directed towards one side of the chain while one elongated seta is directed towards the opposite side. The spherical colony is formed by intertwining of the long setae from numerous cells. - source
Diatoms are clearly the most nimble plankton. With that much food available for grazing, we should expect to see some grazers gearing up to exploit it. I saw a few, but not many as yet. One category I'm watching out for is harmful toxin-producing dinoflagellates. One species that can be harmful, depending on what it eats, is this one, Protoperidinium, with the three "horns". I saw very few of these. I'm hoping one of these days to catch Protoperidinium in the act of feeding, which is really cool. Stay tuned for that.
Very few grazing zoopkankton as yet. A few copepods and invertebrate larvae. Here's a barnacle larva.
Larger plankton feeders are gulping down this bounty. On the side of the floating dock where I collected the sample, filter-feeding barnacles, mussels and tube worms form a solid mass from the surface of the water on down. Since the dock goes up and down with the tide, these creatures have the luxury of constant immersion (although the less fortunate upper zone relies on intermittent waves and swells).
Here's a better view of the tube worms, also known as Feather Duster worms (and to some, fishing bait), Eudistylia vancouveri. The reddish-purple feathery plumes grasp drifting plankton and pull the catch down into their tube. The plumes are delectable to fish, so the worms are able to retract them instantly.
Other chain-form diatoms in the sample: Coscinodiscus and Melosira. We'll see these again in a moment.
June 6, 2014
Today I was out on the beach again and saw a new bloom. This "tomato soup" coloring of the shallow near-shore water is characteristic of Noctiluca, a giant dinoflagellate that explodes in growth around here when we get hot sunny days in summer, proliferating along the warm shallow shores. We've had a heat wave in the Northwest lately...high temps in the 60s for days on end!
Noctiluca is almost big enough to see without a microscope but I checked it out. That's indeed what we have:
Noctiluca feeds on blooming diatoms. You can see strands of the diatoms I showed you above now inside Noctiluca cells, today's feasts.
Last photo is for scale. It's hard to imagine all this drama happening invisibly out in the water, but given that these translucent irregular objects in the photo below are grains of sand, we can get a better sense of the vast numbers of creatures at work out there in the bay right now.
What's up in nature in your backyard? Is this spring or summer where you are, and how do you tell that? All reports of nature's activity welcome in the comments.
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