Saturday 28 December 2013

Kelp

We took a short walk this morning along the beach below our house, where mounds of kelp have been washed up by the recent gales.  We use kelp on our vegetable beds, with wonderful results, but it's often sold, in packaged form, as a health supplement.  It's credited with amazing properties, including helping with weight loss, anti-ageing, hair growth, and as a supplement for iodine, calcium and a mass of other vitamins and minerals.  The sheep that are down from the hill for tupping had obviously heard all this as they were tucking in to the feast, and one does wonder whether the local crofters shouldn't be selling their lambs at a premium as 'kelp-fed Highland lamb'.

The local variety of kelp consists of a 'root', or holdfast, by which it is attached to the rocks, a 'stalk' or stipe, and a number of fronds.  This particular specimen had made the mistake of attaching itself to a rock which was far too light to hold it during the recent storms.

But a few of the kelp stipes had these bulbous, warty structures, some ten centimetres or more across, with a frond coming off the stipe at that point.  They look a bit like flotation bladders, but does anyone know what they are?

At the far end of our walk we came across this small gaggle of geese, who eyed us with irritation before finally flying off to land in the water a few hundred metres away, presumably to wait for us to leave before they returned to their foraging along the shingle.

The dismal weather continues.  The wind has moved into the west and continues to bring in heavy showers: last night we had a further 20mm of rain, making a 36-hour total of 47mm.

2 comments:

  1. Hi Jon: Just checked on line and here is an excerpt:

    University of Southern California Sea Grant Program
    Help with Kelp

    What's that waving back and forth in the ocean? It looks like a tree - a tree in the ocean?! No, it's kelp! Kelp is a type of marine algae, or seaweed. Seaweeds come in three different color varieties, red, green and brown. Kelp is a kind of brown seaweed that grows to be very large. Although kelp resembles a kind of weed or tree, it is quite different from plants that grow on land. First of all, kelp has no roots. Kelp does have a way to anchor itself to the bottom of the ocean floor, but this anchoring system, called the holdfast, does not take in nutrients like plant roots do. The other parts of the kelp also have different names. The "leaves" of a kelp plant are called blades and the "stem" is called the stipe. Another structure unique to kelp is the air bladder, which looks like a small balloon at the base of each blade. The stipe of the kelp is very flexible and cannot stand up on its own - the air bladders help the stipe and blades of the kelp float in the water, which allows the kelp plant to grow up toward the surface of the water, where the sunshine is brightest.

    Keep "singing in the rain".

    Jim Robinson

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  2. What surprises me is that these bladder-like structures are not common, occurring on sometimes only one of the stipes on only a few of the weeds. I've seen pictures of other kelps with bladders, and they seem to be much more common on each plant.

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