Big Seaweed Search/Sussex Kelp

Image: Big Seaweed Search

Big Seaweed Search

This is a great half-term activity for the children, or indeed for anyone at any time. The Big Seaweed Search is a partnership between The Natural History Museum and the Marine Conservation Society.

Why are seaweeds important?

The UK is globally important for seaweeds, being home to more than 650 species. Seaweeds create underwater habitats that provide food and shelter for thousands of marine organisms. They support commercial fisheries (providing nursery grounds for juvenile fish; they absorb carbon dioxide from the atmosphere; they are used in foods, cosmetics and medicines; and they protect our coastlines from storm damage.

Strandliners volunteers at a Big Seaweed Search in Eastbourne

What am I looking for?

By exploring the seashore and recording the living seaweeds you find, you are helping to monitor the effects of environmental change on Britain’s sea life. You are taking part in a real citizen science programme which focuses on three key environmental changes: sea temperature rise, ocean acidification and the spread of non-native species.

Image: Dive magazine

What do I have to do?

The instructions can be found on the Big Seaweed Search website, but are basically as follows:

  1. Start around an hour before low tide.
  2. Select a 5-metre width from the top of the shore to the sea.
  3. Walking away from the sea, explore the whole plot for about an hour, recording only living seaweeds attached to rocks or another hard surface. You only need to record the species from the guide. It is important that photographs are taken as evidence. Photographs are essential for the BSS to be able to use your results.
  4. Upload your results and photographs, using the online form or the app.

Remember to stay safe on the beach. Tell someone where you are, take a mobile phone, wear sensible clothing and footwear (rocks are slippery and may be encrusted with barnacles), don’t go out in bad weather, and wash your hands afterwards.

You can find the Big Seaweed Search guide here
and the Big Seaweed Search recording sheet here.

Meet seaweed researcher Juliet Brodie and Big Seaweed Search participant Jazz in this short video and learn more about why seaweeds are important and how to take part (3:46 mins).

Sussex Kelp Recording Project

What is kelp?

Kelp are large brown seaweeds found along rocky shores. Like marine trees, kelp create a ‘canopy’ beneath which many species takes shelter and find food.

Why is kelp important?

The organisms that shelter and feed here include commercial fish and crustaceans, so kelp supports local livelihoods as well as providing other benefits for nature, people and the planet. Kelp locks away carbon, filters the water and protects our coast from storms by dissipating wave energy.

Vast kelp beds along the Sussex coast (mostly towards the west of the county) once supported a wondrous diversity of marine life. But by the late 1980s, 96% of Sussex kelp had disappeared. This project aims to bring it back.

The journey to kelp recovery started with the Sussex Nearshore Trawling Byelaw. This pioneering legislation created one of the largest trawling prohibited areas in the UK in March 2021. At the same time, the Sussex Kelp Recovery Project was formed to champion, study and facilitate the return of kelp through through progressive, coherent and collaborative action. Find out more here.

There are more videos on the website, but this one, narrated by David Attenborough, launched the project.

You can be part of SKRP’s research programme

Citizen science is a growing discipline that enables us to participate and collaborate in real scientific research and increase scientific knowledge.  We can get involved to help deliver SKRP aims.

Everyone can contribute to restoration efforts via a handy app from the Sussex Wildlife Trust. Whether you’re an occasional beach walker or an avid scuba diver, you can record any kelp you’ve seen on the beach or out to sea, and play your part in the Sussex Kelp Recovery Project. You can register here and find out more about this citizen science project.



A hagstone is a stone with a naturally formed hole. Traditionally, hagstones are flint, the most abundant pebbles on our beaches in South-East England, typically grey or brown in colour and worn smooth and rounded by the action of the sea.

Hagstones on a Sussex beach

What is flint?

Flint is a microcrystalline sedimentary rock composed of silica, formed from the remains of sea sponges and planktonic organisms such as diatoms and radiolarians during the late cretaceous period (60-95 million years ago). Flint was formed in sediments that later became chalk, and so it is found in areas with chalk bedrock, such as the South Downs. As the chalk cliffs erode, the flint is exposed and deposited on the beach.

Flint deposits in chalk – they can often be seen in horizontal bands (Image: The Coastal Path)

How do holes form?

To be considered a hagstone, the hole should have been made naturally. Holes are often made by the wearing away of softer inclusions, for example a fossil sponge embedded in the silica. Sometimes minerals are deposited in small pockets within a rock as it forms. Later these small deposits may weather and erode more quickly than the surrounding rock. The hole may be very small to be begin with, even just a dent, but can be made larger by the action of smaller stones grinding against them through wave action

Hagstone in the making – with fossilised remains

Softer rocks such as limestone or sandstone may have holes made by the activities of marine animals such as burrowing bivalves, marine worms or sponges. These might not have been thought of as hagstones.

Hagstones in folklore

Stones with natural holes play a large role in European folklore. They are are also known as witch stones, adder stones, druid stones, fairy stones or dobbie stones. They were believed to have magical properties, protecting the bearer from witches and ne’er-do-wells.

One belief was that only good luck can pass through the hole, whereas bad luck and curses became ‘stuck’. It was also commonly thought that magic could not work on objects that water can pass through. As the stone’s shape resembles an eye, it acted as a talisman to ward off ‘the evil eye’ (a prominent tradition in Eastern Mediterranean and Western Asian culture). The hole in a hagstone was even thought be a portal to the faerie world and could bring good luck to anyone able to make contact.

Traditionally, hagstones were placed on windowsills or above doors to bring good luck or to ward off evil. They were hung with a red ribbon above the bed or nailed to the bedpost to protect against nightmares. Across Britain, they were hung above stables, sometimes tied to a piece of iron (which also repels witches) to stop witches riding the horses during the night or above cattle sheds, to stop witches turning the milk sour.

In Dorset, fishermen used a hagstone as a protective amulet, threaded onto the rope used to haul the boat up the beach: the boat was thought to be witched if it did not bring in a good haul. In sailing ships, hagstones tied to the mast or a line of stones tied together with string and nailed to the hull were used as protective talismans to ward off witches or to attract good sailing conditions at sea. This tradition was particularly prominent in the South-West. In Sussex there are records of stones with holes used by a midwife to cure children’s diseases and prevent adults catching them. Other uses included tying one to your keys to stop them getting lost, and worn as a pendant for personal protection.

Hagstones were often thought to have been formed by adders: traditionally, on the evening before May 1st, there was a gathering of snakes, which curled together in a ball with a hole in the middle, leaving their hardened saliva behind. In The Mabinogion (the earliest Welsh prose stories) such a stone helps Peredur to escape a lake monster and Owain to escape a castle by becoming invisible. Another theory is that the hole is caused by the bite of an adder: giving rise to the notion that the stones could protect against snake bites.

Local stories

You can check out any time you like, but you can never leave… (Image: Hastings in Focus)

Hastings is supposedly under an enchantment known as Crowley’s Curse, put on the town by author and ceremonial magician, Aleister Crowley. It is said that anyone who has lived in Hastings is compelled to return, no matter how far away they move or for how long. The curse can only be broken by taking a hagstone from Hastings beach!

There is an interesting article in the journal Elementum, entitled In the Eye of the Hagstone, Under the Spell of Flint on the Sussex Coast, by Alex Woodcock. You can read it here.

Whatever you believe, perhaps there is still magic in a mindful walk along the beach, whether we are removing plastic pollution from the environment, looking out for special treasures, or just enjoying the sea air.     

We must add a disclaimer here: under the Coastal Protection Act 1949, the removal of any natural material, such as sand and pebbles from beaches in the UK is illegal.


Mermaid Purses

Some sharks, and all true skates, reproduce by laying eggs. These are surrounded by a tough leathery capsule (made of keratin) that protects the embryo as it develops. After several months these are ready to hatch, and a fully-formed shark or skate will emerge. 

Once empty, the egg cases (or mermaid’s purses) often wash up on the beach. The best places to find them is among the strandline, where the seaweed washes up. By looking at the size, shape and features of the egg cases you find, you can tell identify the species.

The Great Eggcase Hunt began in Devon twenty years ago. It now asks us to become citizen scientists by looking for egg cases and recording our finds. These can indicate species presence and diversity.

Preparing your egg cases

The egg cases washed up on the strandline are often dried out. Rehydrating them makes them much easier to identify, as they expand to their true size.

Fill a container with freshwater and submerge the egg cases. leave to soak for several hours, especially if they are large or very dry. Remove from the water and compare to the ID chart. Don’t forget to take measurements – and photographs – then you can upload the results to the Great Eggcase Hunt website.


You can find the ID guide here.

You can find the ID key here.

You can also download the Shark Trust App and use this to identify and record the egg cases you find, straight from your phone. If you prefer, you can upload your results through the recording hub. You can see the findings on an interactive map.

The 2023 Great Eggcase results can be found here.

There are lots of ways you can help the Shark Trust by becoming a citizen scientist. You can find out more here.

Spotlight on Undulate Rays

Easily identified by its beautiful pattern, as seen in the video, the Undulate Ray gets its name from the wavy patterns of lines and spots on its dorsal side. Despite being called a ray, it is actually a skate. One difference is the tail – a skate’s tail tends to be stockier, whereas a ray’s is more slender and whip-like (some rays have a stinging spine on the tail). Another difference is that skates generally lay eggs in capsules, whereas rays retain the eggs inside their bodies and give birth to live young.

The Undulate Ray normally lives on soft sandy or muddy sea beds, where their markings help to camouflage them against the sea floor – they often bury themselves just below the surface. They can live for over 20 years and grow up to 90 cm total long. Depending on the size of the individual, their diet can range from small fish to shrimps and crabs.

The Undulate Ray is an endangered species globally according to the IUCN Red List and is a priority protected species in the UK. The threats they face include overfishing and habitat loss. We are lucky here in Sussex to have a thriving population of Undulate Rays, perhaps due to the Marine Conservation Zones we have here, which are allowing the natural restoration of our inshore waters.

Undulate Ray egg case (Image: Sussex Wildlife Trust)


Smartie Lids

One of our unique postcards – can you spot the secret message?

‘Chocolate Beans’ were first produced by Rowntrees in 1882, priced at 2d, but became ‘Smarties Chocolate Beans’ in 1937, and following a trade description issue became ‘Smarties’ shortly after. Production stopped during WW2 due to restrictions on non-essential items, and was reintroduced in 1946 with plain chocolate centres instead of the usual milk, due to the demand for fresh milk. Sweet rationing was not lifted until 1953! Supplies were becoming more stable and Smarties went back to their original specification.

Plastic lids were first used on Smarties tubes in the 1950s, and in the 1960s letters (and occasionally numbers) were added to the underside of the lids, These were designed as a teaching aid, and collected by children.

The lids have undergone many changes over the years. Early lids carried the Rowntrees logo with a letter or number on the back. Some of the early letters were upper case, which were later replaced by lower case letters, just before the change to the new metric size somewhere between 1965 and the mid-seventies. The old imperial lids(A) were 1″ in diameter, slightly larger than the 22 mm metric lids (B), and only came in dark blue, yellow, orange and green.

In the early 1990s Nestle bought out Rowntrees, and the ‘Rowntrees’ wording on the lid was replaced with ‘Smarties’ (C).

Many limited editions have been introduced over the years. Special colour lids were often linked to the smarties inside, for example:
– a white lid (with blue and white ‘Smarctic frostbite’ Smarties containing white chocolate, early 2000s)
– a special green lid (with Gruesome Greenie Smarties)
– a special blue lid (with blue Smarties)
– a silver lid (with brown and red cola-flavour Smarties, 2000)
– metallic lids featuring dinosaurs on three colours of Smarties (~2000).

Special symbols on the reverse of the lids include a Smartian set of 8 different designs in 4 different ‘day-glo’ colours from 1995-96 and a further Smartian set in green in 2002.

There was a football set FROM 2000 with 8 different words (PASS, CORNER, TACKLE, FOUL, BOOKED, PENALTY, SHOOT, GOAL) and 8 different colours.

Much of the information and images here were sourced from various websites including here.


Container Spills

The world’s largest container ship, MSC Irina (Image: Vessel Finder)

It is said that 90% of everything that we eat, wear and consume has once been in a container and transported on a container ship. In 2022, over 250 million containers, with their cargo worth trillions of dollars, were transported around the world. At any point in time, more than 6,000 container ships are in operation.

The 20-foot container, referred to as a Twenty-foot Equivalent Unit (TEU) has become the industry standard reference, so cargo volume and vessel capacity are commonly measured in TEUs. The largest container ships can carry more than 24,000 TEUs, carrying everything from toys to trainers, from figs to fridges, and from motorbikes to medical tape.

MV Rena Monrovia, which grounded off the coast of New Zealand in Oct 2021 (Image: Tasmanian Times)

These containers may be properly packed, stowed and secured, but stacked ever higher, and with factors ranging from severe weather and rough seas to ship groundings, structural failures, collisions, or even human error, some never reach their destination, and are lost at sea. The World Shipping Council, which aims to improve safety in container handling and transport, reported that in the twelve years up to 2020, an average of 1,382 containers fell overboard each year. The winter of 2020-21 saw an unusually high number of weather-related incidents, with an average loss over of more than 3,000 containers over the two-year period 2020 to 2021. In 2022, 661 containers were lost, the lowest percentage loss since records began in 2008.

Containers may break up whilst falling off the ship or hitting the sea floor but also may remain intact for a period of time. The ship’s captain has a responsibility to report to the coastguard any container loss that is either a hazard to shipping or the contents are hazardous.

Unfortunately it seems many of these contents (including plastic) are not deemed a hazard. That is where we can begin to help. When we walk beaches, we can record items that keep washing onto our beaches – HP ink cartridges, Pulman slippers, tea capsules, various shoes and more. Recording may lead to identification of pollution sources and perhaps in time a change of law.

HP ink cartridge (Image: Wikidéchets)

Strandliners aim to catalogue container spill items that have polluted our shores so that more accurate information is available. We also aim to build a table of recorded losses in the English Channel and in the Atlantic that have brought items to our beaches.

One of our much-used sources of information, Wikidéchets, no longer seems to be available, but there are records of finds here.


Christmas Challenge

Back in May 2022, Greenpeace encouraged us to record all the packaging we threw away over a period of a week. Almost a quarter of a million people took part and recorded nearly 6,500,000 items.

The Strandliners challenge…

We are asking you to record all the packaging you dispose of as a family over the Christmas week – from 24th to 31st December (whatever the material) and tell whether it was thrown away, recycled, or kept for reuse, and send the results to Strandliners. This includes food and household packaging, gift wrapping and so on. We are asking all our subscribers to do this as well. 

There is no blame attached to this survey. All the results will be completely anonymous – we are just curious about how much extra waste we all produce at Christmas and may repeat the activity in summer to see what the difference is. We will join in too, and can’t wait to see the results.

How do I record my results?

You can just make a note with pencil and paper, keeping a tally on a daily basis, or you can use a simple spreadsheet, like the one here (with a few examples). Then at the end of the week, email your results to us.

How do I know what can be recycled in my area?

Check your local council for details. In Rother, for example, you can find the recycling page here.

How can I tell whether my Christmas wrapping paper can be recycled?

Foil or glittery paper can’t be recycled, so put it in the bin. As a rule of thumb, if you scrunch it up and it stays scrunched, then it can be recycled. Remove any bows, ribbons and as much sticky tape as possible. If it springs open again, it probably contains a plastic layer, so put it in the bin.

You can make a difference in the weeks leading up to Christmas by choosing to buy paper that can be recycled.