Secrets of the Strandline

Beachcombing can be a really fun activity; I always get a feeling of excited anticipation when I step onto a beach as I never know what I might find. And the brilliance of it is, with the tide coming in and out twice a day there is always something new to discover.

This article will introduce you to some of the natural treasures that may be lurking out there just waiting to be found on the beaches in Shetland. For more information on other projects and activities to get involved in on the beach have a look at our Projects page.

It can be tricky to ID some of the finds as they can look a bit weathered from the sea and the surf. We are always happy to help, either send us an email at shetlandcommunitywildlife@outlook.com or tag us on facebook @SCWG. There is also a brilliant group on Facebook full if local enthusiasts who would love to see all your finds, just search Shetland Seashore Discoveries.

It is great fun hunting for all those natural wonders amongst the strandline but we all know too well that often the man-made and plastic materials on our strandlines can out-number the natural. Why not take a bag and some gloves with you whenever you head to the beach and do a #2minutebeachclean, the wildlife will most definitely thank you! Visit www.beachclean.net/ for more info.


Shark and Skate Eggcases

Copyright: Sally Hubband
Copyright: Sally Hubband

Many skate and shark species around Shetland lay eggcases (also known as mermaid’s purses) which lie on the sea floor or wrapped amongst seaweed and kelp. Each eggcase holds a single embryo which once developed breaks out of the eggcase. These eggcases then often become washed up on our beaches. There are a surprising variety of eggcases and once you get looking it is interesting to see how many different species you can find on a beach. Click here to see our post on the Shetland Eggcase Hunt which will give you all the info you will need to identify the eggcases you find and how to record them. To find put more about the joys of hunting eggcases, read Sally Hubband’s experiences.


Urchins

If you are super lucky you may find an intact urchin but more commonly, as they are very fragile, it is just fragments that are washed up. There are two common types of urchin in Shetland, the Edible Sea Urchin (Echinus esculentus) which has a pinky red shell with white spots where the spines have broken off. The second species is the Green Sea Urchin (Psammechinus miliaris) which as its name suggests is a greenish brown in colour.

You may also find what is know as an ‘Aristotle’s Lantern’ which is actually the mouth part of the urchin and is often found as it is the toughest part of an Urchin. It is used to scrape and tear algae which is then chewed with the teeth.

Copyright ©2003 Daniel P. B. Smith
Copyright MAKY.OREL / CC0

Sea Potato

Copyright: S. Rae

Sea Potatoes (Echinocardium cordatum) are a relative of the sea urchin and are also known as heart urchins. They are a sandy colour with fine spines which give it a hairy appearance although these spines may have been worn off in the surf.


Jellyfish

Jellyfish in their adult stage, are not long-lived creatures and once they have spawned, they will die. Moon Jellyfish (Aurelia aurita) are the most common jellyfish found in Shetland. They are easily recognised by its transparent bell with four pink-purple rings. As they are often found in large shoals and spawning happens en masse, large numbers of these jellyfish (sometimes in their thousands) can often be washed up on beaches at the same time. Moon jellyfish feed on plankton and as such only have a mild sting which is unlikely to be felt by humans.

Blue Jellyfish
Copyright: Malene Thyssen

The largest jellyfish to visit our waters is the Lion’s Mane Jellyfish (Cyanea capillata) which is commonly seen at sizes of 0.5m in the UK but can grow up to 2m in diameter in Arctic waters. It is known as the Lion’s Mane due to the mass of tentacles around the underside of the bell and the jellyfish’s brown-red colouration. Care should be taken if you come across one in the water or on the shore as their sting is severe and they are still able to sting even when dead.

Moon Jellyfish
Copyright Kathryn Allan

The Blue Jellyfish (Cyanea lamarckii) grows up to around 30 cm and can range from pale yellow-brown (younger specimens) to light blue-purple. They have trailing stinging tentacles on the underside of the bell along with clusters of stinging tentacles on the upper surface of the bell. Their sting is fairly mild and similar to that a stinging nettle.

Lion’s Mane Jellyfish
Copyright W.carter / CC0

Goose Barnacles

Copyright: Rachel Shucksmith

The Common Goose Barnacle (Lepas anatifera) is the most commonly found species of goose barnacle on our shores. They are a type of crustacean which spend their lives attached to drifting objects floating on the ocean’s surface. They have a flexible stalk which attaches to the floating object with a shelled ‘head’ which protects its feeding legs. These feeding legs uncurl from the shell and catch floating plankton. Goose barnacles are often found in large clusters on objects that have become washed ashore.


Whelk Eggs

These are one of the commonest finds on our beaches. They have a spongy appearance and are often mistaken for a type of natural sponge and were in fact used by mariners for washing in the past. These egg masses are actually from either the Common Whelk (Buccinum undatum) or the Red Whelk (Neptunea antiqua) which are both common species around Shetland.

Copyright: Sarah Smith

Cuttlefish Bones

Copyright: Christine Matthews

These are less common on Shetland beaches compared to the rest of the UK. They are from the Common Cuttlefish (Sepia officinalis) and can be up to 40cm in length. Cuttlefish are molluscs and members of the cephalopod family along with squid and octopus. The bone that is washed up is filled with gas and used to control buoyancy by adding or releasing the gas. As these bones float, they are easily washed onto beaches. They are made from calcium carbonate and have many uses including as a dietary supplement for birds and reptiles.


Sea Beans

These are actually plant seeds that are specially designed to drift long distances in water. They have a very strong outer shell that stops water from penetrating inside and rotting the seed, some have air pockets on the inside to keep them buoyant. These seeds generally come from tropical plants that may have spent months or even years drifting across the Atlantic from the Americas, and the West Indies. You would have to be very lucky to find one of these drift seeds in Shetland as they are very rarely reported. There are a handful of different species but two of the most likely would be the Sea Heart from the Entada gigas plant or a Horse-eye Bean (sometimes known as hamburger bean) from the Mucuna spp.

Sea Heart
Copyright: Jeff Delonge
Horse-eye Bean
Copyright: BAxelrod

On rare occasions larger animals may become stranded or wash up on the beach. Please note that marine mammals can carry a variety of diseases than can be transferable to humans  – please don’t touch or allow dogs to get too close.  If possible try to take a variety of photos and estimate the length – this will help with ID.

If you find a stranded marine mammal contact the SSPCA on 03000 999 999 or the Hillswick Wildlife Sanctuary on 01806 503348. For more advice visit their website https://www.hillswickwildlifesanctuary.org/advice/

If you find a dead marine mammal on the shore report it to the Scottish Marine Animal Stranding Scheme on www.strandings.org/ or to NatureScot (formally SNH) who will coordinate collection of samples or sending the animal south for post mortem examination.  For dead otters please also report them to NatureScot on  01463 667600 (Lerwick office) or NORTH@nature.scot