Seaweed Strands with Crinkled Kelp

Thick mats of seaweed wash ashore on beaches along the Jurassic Coast. Dead seaweed is often automatically viewed as horrid, unsightly, and a nuisance – but if you pause and look, there is beauty in it. There are many types of seaweed to be discovered in the masses on this strandline. Their fronds intertwine in a kind of accidental natural weaving. Each species has its own characteristic shape, texture, and pattern. Their combined presence forms greater abstract designs of infinite variety, the individual fronds making strands or threads as in a tapestry. The puckered patterns of the crinkly Sugar Kelp stand out as the most decorative features of the assemblage. The colours change from deep olive brown to golden yellow and cream as the algae decompose. The textures range from leathery to satiny, from slimy to crispy depending on moisture content. Opaque and hardening on exposure to air; or translucent and soft when floating in shallow water rock pools.

Strandline Seaweeds at Ringstead Bay

A fresh strandline assortment of seaweeds of different colours and textures.

Many UK shorelines are characterised by the wealth of seaweeds that colonise them. These seaweeds are as often likely to become detached from where they have settled and subsequently wash ashore, sometimes in great profusion and abundance. The textures and colours are varied with representatives of many groups – often with species of brown (Phaeophyceae), green (Chlorophyceae), and red (Rhodophyceae) marine algae. They contribute to a great multi-coloured strandline along the waters’ edge and provide the average beachcomber with an opportunity to discover and appreciate varieties of algae normally well out of reach.

A fresh strandline assortment of seaweeds of different colours and textures.

A fresh strandline assortment of seaweeds of different colours and textures.

A fresh strandline assortment of seaweeds of different colours and textures.

A fresh strandline assortment of seaweeds of different colours and textures.

A fresh strandline assortment of seaweeds of different colours and textures.

A fresh strandline assortment of seaweeds of different colours and textures.

A fresh strandline assortment of seaweeds of different colours and textures.

COPYRIGHT JESSICA WINDER 2013

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Kelp Textures at Ringstead

Detail of entangled branching rootlets of a detached kelp holdfast on a beach stone at Ringstead Bay, Dorset, UK, (1) 

This tentacle-like entanglement, which seems to exude blood as it clings to the pebble, is a kelp seaweed holdfast washed ashore at Ringstead Bay, Dorset. It is likely to be from a Tangleweed or Oarweed – Laminaria digitata (Hudson) Lamouroux. It has been separated from the stem and frond of the alga so it is difficult to name with certainty. It could also be from a Sea Belt or Poor Man’s Weather Glass, Laminaria saccharina (Linnaeus); both types of seaweed wash up on this beach.

The wrinkled leathery texture of the wavy-edged stem of some kelp drying out on the beach at Ringstead Bay, Dorset, UK (2)

The wrinkled, leathery, rufous brown subject for the second photograph is a detail of the strongly-waved, frilly edge of a flattened seaweed stem. This is part of the Furbelows kelp, Saccorhiza polyschides (Lightfoot) Batters. The stem is changing from its normal greenish brown to a darker reddy brown colour; and from a smooth thin structure to one with a thicker, rougher, rippled texture as it dies and dries out.

Translucent kelp frond with water droplets on the beach at Ringstead Bay, Dorset, UK (3) 

This third photograph shows one of many kelp fronds on the Ringstead shore that had completely lost their colour and opacity. The washed-up fronds were clear or tranlucent and seemed to both contain bubbles or capsules within the structure as well as to be covered on both upper and lower surfaces with droplets of rain water. The light was reflected by the shiny, smooth, wet surfaces. These fronds might be from either the Furbelows, or Tangleweed or Cuvie kelps – the isolated fronds or blades being indistinguishable to the casual observer.

The features that resemble bubbles in the blades are probably “unilocular sporangia” from which the spores for the new generation of kelp develop. 

The fourth and final photograph below shows a detail of the holdfast which is typical of the Furbelows kelp. It is a hollow, approximately ball-shaped structure by which the seaweed attaches to rocks. The surface is warty and there are short, stubby rootlets.

Knobbly texture of a drying globular kelp holdfast at Ringstead Bay, Dorset, UK (4)  

Revision of a post first published 29 September 2009

COPYRIGHT JESSICA WINDER 2011

All Rights Reserved

Crinkly seaweed from Ringstead Bay

Crinkled puckered glossy seaweed (Laminaria saccharina), also known as Sea Belt or Poor Man's Weatherglass - View 1 

Sea Belt is a very common British seaweed. It is also known as the Poor Man’s Weatherglass because, if you hang it up crisp and dry, it will go limp in damp weather and forecast the rain. Its Latin name is Laminaria saccharina (Linnaeus) Lamouroux. This seaweed has the most wonderful glossy, crinkled, wrinkled, folded, and wavy flat fronds. The texture is mostly puckered like the fabric called seer-sucker. I have previously described this species in more detail in Kelps at Kimmeridge Bay and Three brown seaweeds from Studland Bay in spring.

I recently bought an old book called A Popular History of British Seaweeds -comprising their structure, fructification, specific characters, arrangement, and general distribution with notices of some of the Fresh-Water Algae. It was written by the Rev. D. Landsborough, A.L.S. and published in London in 1857. 

Landsborough’s book is a total delight to read and a mine of interesting information – although some facts are now out of date. It is illustrated throughout with beautiful hand-tinted plates on which the previous owner has most carefully labelled each seaweed specimen in neat pencilled handwriting. As a clergyman, the writer was keen to remind the reader that everything he described was a wonder of nature for which the Almighty must be thanked. 

I thought you might be interested to read an excerpt from the Reverend gentleman’s account of Laminaria saccharina.

The full-grown plants are not only beautifully waved at the margin like the young plants, but they are frequently bullated and rugose, and thickened at the centre. The substance varies from cartilaginous to leathery. The colour is olive-brown, tinged with yellow. It is well deserving of the name saccharine, for, as I mentioned before, it has been proved, by my friend Dr. Stenhouse, to be rich in mannite, which is nearly as sweet as sugar. With all this however to sweeten it, it is not relished as food; indeed the Norwegians, we are told, esteem it so lightly that they call it Toll-tare, implying that it is fit food for the Fiend. But He who made all things very good, made it for good purposes. It is not despised by the farmer, who finds that it yields nourishment to his crops. It is a great favourite with some of the beautiful “minims of nature”, and the young naturalist will find that he is amply repaid for the careful examination of its fronds. Beautiful mollusks may be found gliding along them, and they are the fixed habitation of many zoophytes: Flustra membranacea covering it to a great extent with its fine, silvery, lace-like web.

“Huge Ocean shows, within his yellow strand,

A habitation marvellously planned,

For life to occupy.” 

 Crinkled glossy Sea Belt or Poor Man's Weatherglass seaweed (Laminaria saccharina) on the shingle beach at Ringstead, Dorset, UK. View 2

Crinkled puckered glossy textured seaweed (Laminaria saccharina), also known as Sea Belt or Poor Man's Weatherglass - View 3

Detail of the wavy, folded edge of the crinkled, puckered, glossy textured seaweed (Laminaria saccharina), also known as Sea Belt or Poor Man's Weatherglass - View 4

Detail of the shiny, puckered texture of the kelp Laminaria saccharina, also known as Sea Belt or Poor Man's Weatherglass - View 5

Detail of the wavy, glossy border of the kelp Laminaria saccharina, also known as Sea Belt or Poor Man's Weatherglass - View 6

Detail of the puckered, shiny , central blade of Sea Belt or Poor Man's Weatherglass seaweed (Laminaria saccharina). View 7

Detail of the frilly translucent edge of Sea Belt or Poor Man's Weatherglass seaweed (Laminaria saccharina). View 8

Detail of the wrinkled and rumpled glossy frond of Sea Belt or Poor Man's Weatherglass seaweed (Laminaria saccharina). View 9

Sea Belt or Poor Man's Weatherglass seaweed (Laminaria saccharina) washed ashore on the pebble beach at Ringstead Bay, Dorset, UK - part of the Jurassic Coast. View 10

Revision of a post first published 8 March 2010

COPYRIGHT JESSICA WINDER 2011

All Rights Reserved

Furbelows Seaweed at Studland Bay

Furbelows seaweed (Saccorhiza polyschides (Lightfoot) Batters, washed ashore at Studland Bay, Dorset, UK, on the Jurassic Coast 30.08.2011 (1)

The seaweed that had washed ashore most frequently, when I recently visited Studland beach, was a brown kelp commonly called Furbelows, with the Latin name Saccorhiza polyschides (Lightfoot) Batters. The interesting features of this common British brown alga (Phaeophyceae) are the odd bulbous hollow holdfast with its warty surface texture and ‘rootlets; and the curious thin, flat, wavy, and folded edges that project from the stem. Both of these characters are shown in close-up photographs here. I have also written about this species in earlier posts where you can find more information about FURBELOWS: https://natureinfocus.wordpress.com/?s=Saccorhiza+polyschides.

Close-up the holdfast of the Furbelows seaweed (Saccorhiza polyschides (Lightfoot) Batters, washed ashore at Studland Bay, Dorset, UK, on the Jurassic Coast 30.08.2011 (2)

Close-up of the warty surface texture of the holdfast on the Furbelows seaweed (Saccorhiza polyschides (Lightfoot) Batters, washed ashore at Studland Bay, Dorset, UK, on the Jurassic Coast 30.08.2011 (3)

Close-up of the thin wavy folded edgeson the edge of the lower stem of the Furbelows seaweed (Saccorhiza polyschides (Lightfoot) Batters, washed ashore at Studland Bay, Dorset, UK, on the Jurassic Coast 30.08.2011 (4)

Close-up of the wavy flattened and folded edges on the edge stem of the Furbelows seaweed (Saccorhiza polyschides (Lightfoot) Batters, washed ashore at Studland Bay, Dorset, UK, on the Jurassic Coast 30.08.2011 (5)

Furbelows seaweed (Saccorhiza polyschides (Lightfoot) Batters, washed ashore at Studland Bay, Dorset, UK, on the Jurassic Coast 30.08.2011 (6)

COPYRIGHT JESSICA WINDER 2011

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Thongweed: perennial discs & fertile straps

The button-shaped fixed perennial frond of Thongweed that seasonally bears, and sheds, long fertile straps; on rocks at Winspit, Dorset, UK - part of the Jurassic Coast (1) 

Masses of the  olive-green seaweed, commonly known as Thongweed,  are a frequent sight on the seashores along the Jurassic Coast. The Latin name for this type of brown alga is Himanthalia elongata (Linnaeus) Gray.

These tangled stringy heaps represent just a part of the whole seaweed. They are the seasonally produced free-floating reproductive parts. They are cast off periodically from the longer-lived, fixed, part of this member of the group Phaeophycae. The perennial part is permanently fixed to the substrate in deep inter-tidal rock pools low on the shore or off-shore. It is not so frequently observed or recognised as the straps. 

The perennial part of the alga is surprisingly small given that the fertile straps can be more than two metres long. The plant starts off as a small club-shaped structure a few millimetres wide and attached by a short stalk to the rock. The swollen tip gradually enlarges and flattens out into a roughly circular, flattened disc about 30 mm wide with a dimpled or concave surface – resembling a button or mushroom.

Photographs of this structure are shown above and below. They were found in pools on the rock platform at Winspit – near to extreme low tide – growing on Pink Paint (a calcareous encrusting alga) amongst Coral Weed and other filamentous red seaweeds. Two small bumps in the middle of the cupped surface indicate where the reproductive straps were once attached.

The long straps change from their original light olive green colour to a more yellowish shade with brown spots when they are ripe and ready to shed the reproductive products into the sea. This is shown in the photographs below. 

Thongweed has also been described in earlier posts. These include:

Thongweed at Chapmans Pool

Tangled thongweed

Seaweed-inspired fabric design 

Two disc-shaped fixed perennial fronds of Thongweed that seasonally bear, and shed, the more familiar long fertile straps; on rocks with Coral Weed and red algae at Winspit, Dorset, UK - part of the Jurassic Coast (2) 

Pale, olive green, mushroom-shaped, fixed perennial fronds of Thongweed that seasonally bear, and shed, the more commonly found long fertile straps; on rocks with Coral Weed and red algae at Winspit, Dorset, UK - part of the Jurassic Coast (3)

Loosely coiled strands of long, mottled yellow-green reproductive straps of Thongweed, floating in a deep rock pool at Winspit, Dorset, UK - part of the Jurassic Coast (4)

Close-up of long, mottled yellow-green reproductive straps of Thongweed, floating in a deep rock pool at Winspit, Dorset, UK - part of the Jurassic Coast (5)  

Revision of a post previously published 27 May 2010

COPYRIGHT JESSICA WINDER 2011

All Rights Reserved