Seaweeds are a fascinating group of organisms. Although they contain chloroplasts (those little bits we all learned about in school which are capable of absorbing the sun’s radiant energy and using it to capture carbon from the atmosphere and to manufacture sugar) they do not possess the systems of water and nutrient conduction (xylem and phloem) that characterize the plants. Well then, if the seaweeds aren’t plants, what are they? The answer is something of a muddle because seaweeds are polyphyletic, meaning that they are derived from a number of different phylogenetic sources (fancy words which mean that this is a large group with a diverse genealogy that goes back 1.5 billion years). Most seaweeds live attached to the substrate (but do not obtain sustenance from it) and a number of different life cycles have been described. They come in a wide variety of colors and their classification reflects this fact so that the largest divisions of algae are the reds (rhodophyta), the greens (chlorophyta), and the browns (phaeophyta). One other noteworthy aspect of the seaweeds is that nearly all are beautiful. I found this very photogenic mass of Ascophyllum while visiting the seaside at Portsmouth. Many of the thickened bladders you see are filled with air and work to float and hold the thallus up in the water column. You may also notice other swellings which look somewhat rougher than the air bladders, these are receptacles which contain conceptacles which produce the gametes. Egg and sperm are released into the water and fertilization occurs externally. The young thallus then settles on an appropriate substrate and the cycle continues. Enough science … let’s end with a poem, a Seaweed Haiku courtesy of another WordPress blog, Echoes from the Silence

Below the surface
unseen entanglements.
Hope floats.


21 thoughts on “Weed

    • Thanks Elke. Also, I very much appreciated the reblog of Samir Chopra’s piece about Sagan. I commented, thinking that you would see it … and apparently it went to his site. What I said was that Sagan was surely one of a kind and that the sense of awe and wonderment that he (Chopra) expressed is characteristic of many of us that that call ourselves scientists. Thanks for the reblog. D

      • Thanks – I see your comment now πŸ™‚ What was captured so well was that nostalgic feeling about science … that is still triggered today … but leaving the door open to a more realistic assessment of the “world of science” at large, including all its imperfections.

    • No … never weeds. With a phycologist in the family one has to be very careful about such things. My title was used more to catch the attention than to be technically correct. D

  1. I always marvel at those under sea documentaries – there’s a whole world down there in vivid Technicolor. Your photo captures that colour perfectly. And I love the addition of the poem.

    • Thanks Jenny. I used to be a great fan of all those Jacques Cousteau films when I was growing up. Then I learned to snorkel and to SCUBA dive in my teens and my first photographic adventures were with underwater images. And even J’s dad is an emeritus prof. of phycology. So, you see … I come by this interest and admiration honestly! Glad you enjoyed this not-quite-under-the-sea adventure! D

  2. Lovely, lovely. Now I know where the term “Hope floats” comes from. Very appropriate to this terrific shot.

  3. Very nice! Traditionally kelp and caplin (Mallotus villosus) were used as fertilizer here in Newfoundland. Our soil is not very good at all. Glaciation has seen to that! What little that remains is rocky and rather acidic. Couple that with a very short growing season (from June to September with half or more of the days being foggy) and you can see that the farmers here have quite an uphill battle. Nonetheless, Potatoes, Turnip, Cabbage and Carrots can be coaxed from the soil with a lot of help from the natural fertilizers that are so abundant. And, Dave, when the caplin and kelp start to rot in the soil. WHEW! The vegetable garden is almost as rank as the cod liver oil drum. In these oil-and-gas crazy times, it’s all something of a lost art, sadly. But, still, all things come in cycles and I have no doubt that once we’ve decided that we’ve pulled enough oil out of the ground we’ll go back to better ways.

    • Ha! The parts about the horrid smells were funny and reminded me of my own story. We have always provided the sheep with mineral supplement; first, because dry hay is a bit deficient (especially if one isn’t feeding grain – as we do not) and second, because the part of the country we live in is deficient in the mineral selenium. For years we purchased this loose, brown, stuff that kinda looked and smelled like brown sugar (they put just a touch of molasses in it to make it more palatable). A couple of years ago our feed store started getting supplement from another supplier. I thought the first couple of bags had somehow spoiled – they smelled nasty. Soon, however, the nasty smell began to remind me of something (remember that I grew up on the coast) … what was it? LOW TIDE! Ah ha! I read the label and, don’t you know, ‘kelp’ was listed as an ingredient! Yes indeed, the stuff is full of ‘the good stuff.’ Now, as far as the fish go … I’m sure they too smell pretty bad at first … but after that I’ll bet they contribute significantly to the supply of available nutrients … and it sure beats shipping more traditional fertilizers (with their huge carbon footprint) to you, at great cost. Nothing like the old ways … what say you? D

  4. What a beautiful capture of the seaweed. I wouldn’t think you could find such a living green thing this time of year in New England. Of course you would! And thank you for the lesson. I have a question, though, regarding seaweed. Do you feed your sheep kelp? The lady that I bought my Merino from supplements her flocks with kelp for parasite-control. I’ve never done it and wondered about how to go about it, what it’s effectiveness is, conditions, etc.. This post made me think to ask you! I also had to share it with my daughter SJ because she loves everything to do with the sea. In January, we had a brief, very brief, visit to Monterey, CA and the kelp gardens at the Aquarium are just spectacular.

    • Sure … supplementation with kelp can be a good thing, especially if you’re not providing another source of mineral supplementation. It’s one of those things which won’t cure an ailing flock and won’t kill a healthy flock. I think it can put a shine on a healthy flock and serve to support and ailing one. Know what I mean? It’s funny, now that I think of it, the loose mineral mix that we provide has a very strange smell. The first few times I opened a bag I’d let out a cry of phewy! After a few bags I realized that it smelled like rotting seaweed, so I’m pretty sure that is the source of some of its salts and micro-nutrients. I don’t think it’s a good idea to over do the minerals though … do you supply any now? I’ve never looked to see whether Vermont is lacking in Selenium, but we are here in PA and were in IN and have always provided a mix with supplemental Selenium (one needs to be careful about White Muscle Disease). Also, be careful about using just any supplement and read labels … for example, bovine supplements have too much copper for sheep. So I’d say that if you’re already supplementing then a bit of kelp top-dress wouldn’t hurt and may surely help. If you’re not providing anything at all then sprinkling some kelp over the hay would be a good way to feed the stuff – but be careful about feeding rates. Kelp is high in all sorts of minerals and iodine as well. Are you going to harvest and dry and process? If so, the genus pictured (Ascophyllum) is mentioned in some mixes I’ve seen. The stuff is marketed as a ‘Kelp Meal.’ I’d be careful to read labels though and make sure to avoid excess copper. Kelps are such a good source of salts that it is a component of the fertilizer we spread on our hay fields! If you close your eyes after spreading you’d think you were by the beach! Bottomline, top dress if you’re already supplementing and feed at appropriate rates if you’re not already supplementing … but read labels in both cases. As far as supplementation with kelp as a method of parasite control. Hmmm, I’m not sure about that one. I’ve heard of using diatomaceous earth, but you know … I’m sorry, I’m gonna stick with Ivermectin, I hate to think I’m being conservative. We’ve used it in the flock for nearly 25 years, never seen any signs of resistance, and our sheep are always ‘clean.’ Let me know if you’ve got any other questions. Always love dropping my two cents into the mix. D

      • Can’t say that I seek them out, but when I find them I take advantage of the opportunity to have most things in focus. Even with non-planar subjects, I often find myself moving the camera into different orientations to find one that yields the greatest number of important things in focus simultaneously.

  5. Never gave much thought to seaweed except how to avoid it when swimming in the ocean! The water is so aqua-blue, doesn’t look like the Atlantic Ocean!

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