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.

Sea Belt Seaweed or Poor Man’s Weatherglass

Close-up image of shiny natural pattern and texture on Sea Belt Seaweed - Laminaria saccharina

For more information about Sea Belt or Poor Man’s Weatherglass seaweed – Laminaria saccharina (Linnaeus) Lamouroux – see the earlier Postings about this species on Jessica’s Nature Blog.

Sea Belt seaweed, Laminaria saccharina, washed up on a pebble beach

Sea Belt seaweed, Laminaria saccharina, washed up on a pebble beach

Sea Belt seaweed, Laminaria saccharina, washed up on a pebble beach

Close-up image of shiny natural pattern and texture on Sea Belt Seaweed - Laminaria saccharina

Close-up image of shiny natural pattern and texture on Sea Belt Seaweed - Laminaria saccharina

Close-up image of shiny natural pattern and texture on Sea Belt Seaweed - Laminaria saccharina

Close-up image of shiny natural pattern and texture on Sea Belt Seaweed - Laminaria saccharina

Close-up image of shiny natural pattern and texture on Sea Belt Seaweed - Laminaria saccharina

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

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Pictures from a November walk at Studland

Seashell picture: Manilla Clam with graphic black zig-zag markings, on rain-pocked sand, Studland, Dorset, UK - part of the Jurassic Coast, 27 November 2009 (1) 

This is a series of pictures showing some of the things I noticed as I walked along Knoll Beach at Studland late on a cold, wet, dull, afternoon at the end of November. The beach was virtually deserted although the many footprints showed that it had been a busy afternoon despite the wintry weather and overcast skies. There were a fresh assortment of natural ‘treasures’ to be found on the wet, rain-pocked, surf-washed, sand. These included empty Chequered Carpet shells with graphic black markings; live clusters of Slipper Limpets; an occupied Common Mussel with a Sea Belt holdfast attached; pieces of pale green and dark brown beach glass;  and red, orange and brown seaweeds decorating the strandline.

Seaweed picture: Red, orange and brown seaweeds washed up on the sand at Studland, Dorset, UK - part of the Jurassic Coast, 27 November 2009 (2) 

Beach picture: View of the virtually deserted sandy Knoll Beach, Studland, Dorset, UK - part of the Jurassic Coast, late afternoon with overcast skies and grey clouds after rain on 27 November 2009 (3) 

Sea glass picture: Pale green sea glass on rain-pocked sand at Knoll Beach, Studland, Dorset, UK - part of the Jurassic Coast, 27 November 2009 (4) 

Seaweed picture: Brown seaweed washed up on the wet sand at Knoll Beach, Studland, Dorset, UK - part of the Jurassic Coast, 27 November 2009 (5)  

Seashells picture: A cluster of living Slipper Limpets found on Knoll Beach, Studland, Dorset, UK - part of the Jurassic Coast - 27 November 2009 (6) 

Seaglass image: Brown sea glass found on Knoll Beach, Studland, Dorset, UK - part of the Jurassic Coast - 27 November 2009 (6) 

Seaweed picture: Sea Belt brown seaweed attached to a living Common Mussel on wet sand at Knoll Beach, Studland, Dorset, UK - part of the Jurassic Coast - 27 November 2009 (8) 

Mussel shell picture: A living Common Mussel with the holdfast of a Sea Belt seaweed attached to the shell, washed ashore at Knoll Beach, Studland, Dorset, UK - part of the Jurassic Coast, 27 November 2009 (9) 

Strandline picture: Seaweed and shells on the new wet sandy strandline at Knoll Beach, Studland, Dorset, UK - part of the Jurassic Coast - 27 November 2009 (10) 

Revision of a post first published 12 January 2010

COPYRIGHT JESSICA WINDER 2011

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Three brown seaweeds: Furbelows, Sea Belt & Spiral Wrack from Studland Bay in spring

Common British seaweeds picture: Furbelows seaweed, Saccorhiza polyschides, washed ashore onto the sandy beach at Studland Bay, Dorset, UK, on the Jurassic Coast World Heritage Site (P1070086Blog1) 

Seaweeds usually start off life attached to rocks. Although Studland Bay is famous for its beautiful fine, clean sand, there are rocks to the west of the bay near Old Harry Rocks, and also the artificial substratum of what is locally termed the Training Bar. The Training Bar runs from the junction of Shell Bay and Knoll Beach (both are parts of Studland Beach) seawards in an approximately south-westerly direction. It is signposted with beacons on poles. Its purpose is to guide boats safely into the narrow entrance to Poole Harbour by the Sandbanks Ferry.

Seaweed becomes detached from the rocks for many reasons but most commonly due to strong wave action in stormy weather. The weed then floats around and often gets washed ashore. Because the weed may have been swilling around for a considerable time, the condition may be poor when it is found on the beach.

Most of the time the quantities of weed are moderate, scattered and impermanent  – it gets washed out to sea on the next tide. Occasionally vast banks of weed accumulate and do not disperse. If this happens, the National Trust (who own the beach) have hit on the novel idea of bagging it up and selling it as fertiliser for the garden. It makes excellent enrichment for the soil. For centuries, people have gathered seaweed for this purpose. In Alderney in the Channel Islands, for example, you can find evidence of the former wrack-gathering activities in the cobbled ramps that lead down to the beaches; these were constructed for the carts to get down to the shore. 

The top picture shows the commonly occurring kelp called Furbelows, Saccorhiza polyschides(Lightfoot) Batters, washed up at Studland Bay, Dorset. It is one of the largest brown seaweeds or Phaeophyceae. It has long strap-like leathery fronds. The stalk is short, flat and typically has a wavy ruff or frill either side of it as you can see in the picture below. Sometimes the stalk is twisted at the base. The holdfast at the base frequently has a warty and bulbous hemispherical appearance as well as rootlets. Lots of plants and animals prefer to settle here on both stalk and holdfast. The specimen below has red seaweeds attached to it. 

Common British seaweed photograph: Furbelows kelp, Saccorhiza polyschides (Lightfoot), showing wavy-edged lower stem and holdfast, washed up at Studland Bay, Dorset, UK - part of the Jurassic Coast World Heritage Site (P1070088Blog2)

Sea Belt or Poor Man’s Weather GlassLaminaria saccharina (Linnaeus) Lamouroux, is another large brown kelp but is easily distinguished from Furbelows. The frond is often a single blade and is has a crinkly surface that looks like that old-fashioned fabric known as seersucker.

Common British seaweeds photograph: Sea Belt or Poor Man's Weather Glass, Laminaria saccharina (Linnaeus) Lamouroux, washed up onto the sandy shore at Studland Bay, Dorset, UK - part of the Jurassic Coast (P1070094Blog3).

The stem of Sea Belt is short and slender as you can see in the photograph below. There are no lateral frilly edges. The holdfasts are a series of intertwined rootlets and there is no large bulbous structure.

Common British seaweeds photograph: Stems and holdfasts of Sea Belt, Laminaria saccharina (Linnaeus) Lamouroux, washed up on the sandy shore at Studland, Dorset, UK - part of the Jurassic Coast (P1070110Blog4)

You can find more pictures and information about these two kelps in a previous post – click here for Kelps at Kimmeridge Bay.

Studland Bay seaweed photograph: Flat or Spiral Wrack, Fucus spiralis Linnaeus, washed up on the sandy shore at Studland Bay, Dorset, UK - part of the Jurassic Coast World Heritage Site (P1070122Blog5)

One of the smaller brown seaweeds is Flat or Spiral Wrack, Fucus spiralis Linnaeus, pictured above and below. Like Bladder Wrack and Toothed Wrack it has a central midrib – but it doesn’t have any air bladders and the edges of the fronds are smooth. One of its supposed characteristics, and the one from which it gets the name Spiral Wrack, is the tendency of the fronds to twist -but you can’t rely on this feature alone for identification. When the forked tips of the fronds swell with reproductive products, they are lighter in colour and have a granular appearance. However, these swellings have a distinct longitudinal ridge or border around their edge which is a continuation of the blade or frond. This is one of the diagnostic features for the species.

There are more detailed pictures and explanations about Flat or Spiral Wrack click here for Flat or Spiral Wrack from Chapman’s Pool.

Common British seaweeds photograp: Flat or Spiral Wrack, Fucus spiralis Linnaeus, showing reproductive bodies at frond tips; Studland Bay, Dorset, UK - part of the Jurassic Coast (P1070123Blog6) 

Revision of a post first published 4 June 2009

COPYRIGHT JESSICA WINDER 2011

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Kelps at Kimmeridge Bay

P1050862Blog1 Furbelows, a type of kelp, Latin name Saccorhiza polyschides, still attached by the holdfast to a stone, washed up at Kimmeridge Bay, Dorset, UK on the Jurassic Coast World Heritage Site 

I found three types of kelp washed up on the seashore at Kimmeridge Bay on 15th March 2009. Kelps are the largest of the British brown seaweeds or Phaeophyceae. They are perennials in plant terminology compared with many of the more ephemeral red and green algae that appear seasonally or annually. Kelps all have a flat blade joined to a stalk, sometimes substantial, in turn attached to rocks by a much branched structure called a hold-fast. They live at low water or deeper.

The kelp on the pebbles in the photograph at the top is known as Furbelows, Latin name Saccorhiza polyschides (Lightfoot). It has been washed up onto the shingle complete with the large stone to which it is attached. The holdfast is like a hollow knobbly ball. The stem is smooth and flat, often with a twist just above the holdfast, sometimes with really noticeable wavy or frilly edges. The blade starts off as a single blade but becomes divided up into long straps. The whole thing can reach 4.5m long and 3.5m wide. 

The photograph below shows in detail the characters of stem and holdfast by which this species is identified.

P1050888Blog2 The kelp seaweed known as Furbelows, Latin name Saccorhiza polyschides, washed up on the seashore at Kimmeridge Bay, Dorset, UK on the Jurassic Coast World Heritage Site.

Cuvie, or Laminaria hyperborea (Gunnerus) , is another type of kelp found on the strandline (shown below). This one also has a long stem but with a round rather than a flat cross-section; and the outer surface is roughened and not smooth. The blade is divided up into long straps just like the Furbelows described above. The holdfast is not bulbous in this type but simply a complex of ‘rootlets’.

P1050899Blog3 The kelp seaweed known as Cuvie, Latin name Laminaria hyperborea, washed up on the beach at Kimmeridge Bay, Dorset, UK on the Jurassic Coast World Heritage Site 

Additionally, it is typical that some smaller red seaweeds are actually growing on the stem. You can see these details more clearly in the picture below.

P1050900Blog4 Detail of the rough stem of the kelp seaweed known as Cuvie, Latin name Laminaria hyperborea, with small red agae attached. Kimmeridge Bay, Dorset, UK on the Jurassic Coast World Heritage Site 

The third type of kelp I saw was Sea Belt, or Poor Man’s Weatherglass – Latin name Saccorhiza saccharina Linnaeus. This is easily recognisable from the crinkly puckered blade. You can spot it straight away amongst the piles of seaweed on the Kimmeridge strandline shown in the two pictures below. This weed has a thin short stem and a holdfast of branched rootlets.

When this seaweed is dry, a fine sugar-like powder coating appears on the blade hence the saccharina in the Latin name. Because this dried weed becomes limp again in damp air, it is traditionally used to forecast rain.

P1050895Blog5 The crinkled blades of the kelp seaweed known as Sea Belt or Poor Man's Weather Glass, Latin name Laminaria saccharina, washed up on the shore at Kimmeridge Bay, Dorset, UK on the Jurassic Coast World Heritage Site 

For more information about seaweeds a useful website is Algaebase which is a data base for all agae including marine seaweeds. For more information on the three kelps illustrated click on  Furbelows, Cuvie, and Sea Belt.

For more information about Kimmeridge Bay see the Purbeck Marine Wildlife Reserve Web Site.

P1050893Blog6 An assortment of seaweeds washed up on the beach at Kimmeridge Bay, Dorset, UK onthe Jurassic Coast World Heritage Site. Includes the crinkled blades of Sea Belt and Sea Oak with its elongated gas bladders looking like seed pods. 
 

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