Shingle Beach

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When most people think of beaches they think of sand. They do not want to rest upon a thousand bumpy stones. Beaches decorated with pebbles rather than sand are called shingle beaches.

Ballycastle, Antrim, Shingle
Ballycastle, Antrim, Shingle

Shingle beaches are common – Britain has thousands of them, although Japan and New Zealand have more. There is a national registry of shingle beaches in Ireland which has focused on 153 of them.

Brighton beach is famous for its flint nodules, the core remainder of a chalky past.

Brighton Beach

These beaches contain beautiful stones – so much so that people like to collect them. Police warned a woman who took stones, to decorate her garden, from a beach near the Dip, Felixstowe, in the UK. A more high profile situation was that of Dr Caroline Lucas, Green MP for the UK parliament. While taking her parliamentary inauguration oath to the Queen she carried in her hand a pebble from her constituency in Brighton – yes from the famous beach. Taking stones and shells, which form an integral part of the city’s sea defences, from the beach is illegal. A Brighton and Hove council spokesman added:

Visitors to Brighton and Hove will always want to take a memento home with them and for some this is a pebble or sea shell from the beach and on the face of it this seems relatively harmless. However the problem is that the city has a perpetual sea defence problem and pebbles play their part in protecting the seafront.

Rossglass Beach
Rossglass Beach

The National Shingle Beach Survey of Ireland 1999 focused more on the rare vegetation encouraged by the stony terrain, rather than the stones itself.  53 sites in counties Donegal Sligo, Mayo, Galway, Clare, Kerry,
Cork, Waterford, Wexford, Wicklow, Dublin, Meath and Louth were surveyed. A shingle beach was defined

Rich in stones of approximately 2mm to 250mm in diameter which have been worked by the sea, giving them a rounded or smoothed shape.

Beaches dominated by larger particles (up to 1.5m in diameter – which is quite a large particle!) were considered boulder deposits, but also included in the survey. In New Zealand shingle beaches are defined as the top 10 cm of the surface, > 50% of the volume comprises particles > 2mm in diameter (upper size of sand).  No greater than 50% of the surface can be covered with boulders (rocks > 256 mm).

The following are habitats related to shingle beaches

  • Intertidal shingle – areas of rounded shingle periodically flooded by the tides. Important feeding habitat for many birds.
  • Lagoon – a body of water forming on the landward side of the beach, usually tidal and brackish in nature fed by one or more streams, rivers or rivulets. The lake may exit through a channel in the shingle or may seep through without forming a channel
  • Lowland Karst – areas of exposed limestone pavement.01-limestone-pavement-karst
  • Machair – dry sandy grassland forming behind the beach, typically grazed, potentially shingle based.
  • Rocky shore – outcrops of bedrock frequently washed by the sea or salt spray.
  • Saltmarsh – sand or mud based areas of land frequently inundated by seawater. Dominated by Salicornia, Puccinellia and Spergularia species.
  • Sand Dunes – Ammophila dominated, wind formed, drifts of vegetated sand found behind the beach, may be cobble based.
  • Shingle based grassland – shingle worked by the sea forms the underlying substrate of grassland. Maybe grazed or not, typically dry, dominated by Festuca rubra, Lotus corniculatus, Trifolium repens and others.

 

References

https://www.irishtimes.com/news/environment/eye-on-nature-the-shifting-sand-shingle-and-stones-beneath-our-feet-1.1890411

https://www.irishexaminer.com/world/police-warning-over-beach-pebble-haul-245101.html

http://www.theargus.co.uk/news/8179509.Caroline_Lucas_says_she_has_returned_Brighton_pebble/

https://en.wikipedia.org/wiki/Shingle_beach

https://www.npws.ie/sites/default/files/publications/pdf/Moore_%26_Wilson_1999_Shingle_Beach_Survey.pdf

https://www.landcareresearch.co.nz/science/plants-animals-fungi/ecosystems/conservation-science/shingle-beaches

 

Storm Emma brings Snow to Dublin

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Storm Emma was a snow storm blizzard that hot Ireland in March of 2018, having arrived from the direction of the Bay of Biscay in France. It was the worst snow storm to hit Ireland since 2009, and brought the country to a slowdown for two working days. It is not often that Dublin experiences such level of snow. And here are some photos from the week when Emma dropped into town.

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Sponges and similar animals

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Sponges

On the lower shore sponges can be found beneath rocks. Many are thousands of individual tiny individuals living together. They are simple animals. They absorb water and filter particles of food.

Photo: Paul Naylor www_marinephoto_co_uk

Sea Mats

Form normally in thin areas of seaweeds. rocks, and seashells. Often feel chalky or slimy to touch and are made up of tiny animals called Zooids. Each animal is a kind of box and has a crown of tentacles.

Membranipora membranacea.jpg

Photo: https://en.wikipedia.org/wiki/Membranipora

Sea Squirts

Similar to sponges, these are complex animals. Some live in colonies and others are single. Can grow large, If gently squeezed, can squirt out a jet of water from it’s openings.

 

References

Sea Squirts – https://en.wikipedia.org/wiki/Ascidiacea

Lichens

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Lichens are usually found high up on the splash zone, Tiny algae and fungus live together. Algae live on the inside and fungus on the outside – which provides shape and shelter for the algae (It’s such a beautiful relationship!!). Algae feed by using photosynthesis and then produce sugar which is consumed afterwards by the fungus.

Lichens do not have roots, but absorb water and gases through their upper surface, and are therefore sensitive to atmospheric pollution. For this reason they are rarely found around cities and grow best on the wetter west side of the British Isles. Those on trees thrive best on the sunny, south-west aspects of trunks and branches. Disappearance of lichen species can be used to detect rising levels of air pollution.

There are three main types. The encrusting forms, including the bright orange/dark yellow ‘Xanthoria’ grow on roofs, walls, gravestones, signs and tree trunks. Leaf-like species develop flat lobes spreading over bark or stones, and shrubby forms which grow vertically from the ground or hang from trees. Few have common names.

The main body of the lichen is called a Thallus and each species quite different. Thallus absorbs water from the rain, sea spray, fog and dew. Grow from some millimetres per year to a few centimetres per year, and can live in very typical difficult conditions.

Some Typical lichens:

Leaf encrusting form

Upright or erect form

Tufted form – http://www.geograph.org.uk/photo/1060980

A lichen - Cladonia arbuscula subsp. squarrosa

Granular encrusting form – http://www.geograph.org.uk/photo/1753336 

Bench Mark, Field Bavant

 

Reference:

Image: http://www.geograph.org.uk/photo/1190524

Seaweeds

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Seaweeds belong to the algae family. They are plant like organisms that live in water. They vary in size from small cells to plants 60 metres long. Some are found in seawater and others in fresh water.

Seaweed grows, makes food and reproduces only when covered with water; some survive without water longer than others.

They use photosynthesis to produce food. They don’t have leaves, stems, or roots but have fronds (to absorb light and water), a stipe, and a hold-fast to cling to surfaces

 

Types of Seashores

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There are different types of seashores

Rocky  Shores

These are sometimes bedrock and sometimes boulders. Have lots of spaces for animals and plants to live. They have to deal robustly with strong waves and the constant rose and fall of the tide. Different types of rocks influence what you will fond living on the rock itself. If sheltered those rocks might be covered with seaweed and provides protection and food for a variety of animals. If exposed – by for example the constant hotting of the waves – then this prevents the growth of seaweed

Rock Pools

These are created when the tide goes to and water is trapped in the rocks – live animals can be left behind

Sandy and Muddy Shores

Here animals might leave a hole, burrow, tracks, or a swirl of sand as something buries itself. Sandy beaches contain billions of particles brought in by the waves. Muddy shores usually form near river estuaries (eg. River Avon) where large mudflats can occur. Soil from the fields turns to mud, and comes down the river. When it reaches the sea these mud left overs may end up on the seabed near the sea. This silt is sculptured by the waves into the soft banks.

Shingle Beaches

Lots of pebbles – hard for animals to attach themselves to the rocks. Will only find lichens.

 

The Irish Sea is Born

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It was 20 millions years ago that Britain and Ireland ended up where they are now.  Almost 300 million years before that, the super continent Gondwanaland had began to separate in a north-south movement. Then 100 million years ago this shifted a an east-west separation, and by 40 million years ago the Atlantic Ocean was formed – and the continents as they are now were more or less in place 20 million years ago.

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