The Daily Bucket is a nature refuge.
We amicably discuss animals, weather, climate, soil, plants, waters and note life’s patterns.
We invite you to note what you are seeing around you in your own part of the world, and to share your observations in the comments below.
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October 2019, and past winters
Olympic Peninsula, PacificNorthwest
We saw some nice seafoam at the ocean on our recent visit in October. The weather was unusually calm that week, with the ocean as flat as it gets there and almost no wind, so the seafoam — aka spume — was quivering rather than blowing. I’ve always loved the wildness and drama of ocean beaches, including the drifts of winter seafoam. Unfortunately it appears global climate change is sabotaging even that beautiful and beneficial feature of our coast.
Seafoam is a natural phenomenon. It’s formed when the organic material of offshore algae gets churned up in surf and wind. In this video you can see foam where waves are breaking offshore and onto this Olympic Peninsula beach.
Seafoam is masses and masses of fluffy bubbles. Why doesn’t all surf generate bubbles? Why do only some bubbles persist on the beach?
Getting sciency, we can think of seafoam just like soap bubbles. The organic compounds from decomposing planktonic algae — the fats and proteins — act as surfactants, forming bubbles just as soap does (soap being another surfactant). The more plankton and nutrients in the water, the more bubbles form and the longer they last before popping. A bubble is a layer of water lined on the inside and outside with surfactant molecules, each of which has a hydrophobic end (that points away from the water layer) and a hydrophilic end (that points toward water). The most stable shape for a bubble is a sphere, being the smallest volume the bubble layer needs to stretch around. Further detail on surfactant science can be found at the Exploratorium site which has descriptions and links for deep dives into the physics (eg iridescence), and Algaeworld for more about the biology of seafoam.
Foam can also be formed from the organic material of industrial pollutants and sewage. We’ve all seen that or pictures of foamy disgusting wastewater. The seafoam at the ocean is a part of the natural marine ecosystem — a conversion of nutrients into and out of living organisms to the benefit of other critters living there — but the foam formed from waste products is toxic to the local ecosystem, and often beyond. Get up close to the foam and you can tell the difference.
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Seafoam is light in texture, it’s not slimy and it doesn’t stink. Natural foam is generally white but can have a tinge of color depending upon the type of plankton it comes from or tannins in the water. Old seafoam gets darker as the bubbles break down leaving the nutrient material behind. Ultimately you’ll see clumps of it high up on the beach. It may look ugly but it is a boon of food to the intertidal critters all along the shore, large and small.
We’ve been at the ocean on much stormier days, with bigger surf and stronger wind. Winter conditions tend to stir up more seafoam, sometimes driving it onto shore in big drifts.
Our 2015 visit was so foamy it was hard to walk on some beaches. I took a video at First Beach instead. That’s the Big Log out front. The quivering and swirling of foam is mesmerizing.
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Overall, seafoam is useful in promoting the biomass and complexity of coastal food webs, transferring nutrients from the ocean to this highly rich ecotone that includes shallow water, rocky intertidal, beaches (on and between sand grains), and nearby forests, wetlands, estuaries, and fields. The foam material itself is eaten by amphipods, worms and other invertebrates, as well as fish and even waterfowl.
However there are recent cases of seafoam being problematic, depending on the kind of plankton source. Foam events from Karenia brevis have triggered asthma attacks in Florida among the sensitive as the bubbles break and aerosolize. Last year a major Karenia bloom on the Gulf coast killed thousands of fish, as well as turtles, dolphins and manatees, lasting for months. On this side of the continent major blooms of the harmful red-tide causing dinoflagellate Akashiwo sanguinea caused massive marine bird deaths in 2007 and 2009 along the West Coast; thousands of birds, especially Red-necked loons, Western grebes and Common murres, washed up on beaches. The seafoam surfactants had stripped their feathers of waterproofing, and they had died from hypothermia. Notably, oceanic conditions during these events were extremely anomalous: water temps were 5°C higher than usual and normal seasonal upwellings were impeded by water stratification, the stagnation caused by warm surface temperatures. It didn’t help that the bloom erupted at a vulnerable time for birds, their primary molt stage in early fall.
While Akashiwo sanguinea is a naturally occurring dinoflagellate, the frequency and severity of its blooms have increased in recent decades. Many studies have drawn a clear link between the increase in harmful algal blooms and our changing climate. As the ocean warms and acidifies, dinoflagellates do better than other phytoplankton, destabilizing the base of coastal marine food webs. In other words, between increased nutrient dumping and global climate change — both due to human population pressures — the natural balance of marine ecosystems is shifting, and in this case to favor some populations that are harmful to animals. Seafoam may increasingly signify harmful algae blooms in future, especially where the water is warmer than normal.
As the ocean changes, I’ll be wondering what’s in the seafoam, hoping that this season it is healthy for birds and other animals living by the sea.
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Partly cloudy and clement in the PNW islands of the Salish Sea. Temps in high 40s and calm.
What’s up in nature in your area today?
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