Seagrass in the UK is home and hunting grounds to an incredibly diverse community of animals, from tiny invertebrates to large fish, and marine mammals, making these areas one of the most productive ecosystems in the world! The Seagrass can form dense underwater meadows which is perfect for sheltering animals that are unable to move very quickly, allowing them to form nursery habitats, safe from large predators out in the open.

Read on to find out more about some of the amazing animals you can find in Seagrass habitats around the UK:


The UK has two native Seahorse species – the Spiny and the Short-snouted Seahorse. Although both species of British Seahorse are rare and endangered, they can be found from the Shetland Isles down the west coast of the UK, around Ireland and along the south coast of England. There have also been some sightings of Seahorses on the east coast and out in the North Sea too.


  1. Just like other fish they breath through gills and have a swim bladder, however, they do not have fins and have a long snake-like tail which they use to cling onto Seagrass which helps them stabilise so they don’t float off in strong currents.
  2. Seahorses are some of the only animals in the world where the males become pregnant. Potential mates will court for many days and once they mate, females will place up to 1,500 eggs in a small, specially-adapted pouch on the male’s body. They will stay secure with the male for weeks before emerging, with the females checking on her mate and the eggs daily.
  3. They can change colour to camouflage and match their surroundings. Some have even been known to turn bright red.


There is such a wide variety of Crustaceans that rely on Seagrass habitats for shelter from larger predators. Some of the Crustaceans we have in the UK that can be found often in these habitats include:

  • Squat Lobsters
  • Common Prawns
  • Scampi
  • Spider Crabs
  • Shore Crabs
  • Edible Crabs
  • Shrimps
  • Hermit Crabs
  • Lobsters

Many Crustaceans have a varied diet so Seagrass habitats provide a diverse ecosystem for them to feed on, including different plant matter, Clams, Mussels, Sea Urchins, Starfish, micro-organisms, Shellfish, Worms and Sea Snails.



Cuttlefish are chunky squid-like creatures with well-developed heads, large eyes and mouths with beak-like jaws. They have eight ‘arms’ with suckers plus two tentacles around the mouth and a fin that runs around their body. Cuttlefish are extremely variable in colour, but are usually blackish-brown, mottled or striped.

Fun Facts

  1. They are fierce predators and will eat crabs, small fish and sometimes larger Cuttlefish will even eat smaller Cuttlefish too. That’s why Seagrass beds are the perfect place for them to hunt out small creatures.
  2. Common Cuttlefish eggs are dyed black with their ink, which gives them the appearance of grapes – giving them their name ‘sea grapes’.
  3. They can lay 100s of eggs at a time, which they will often stick to Seagrass to help shelter and protect them. The eggs will then take 1-2 months to hatch depending on sea temperatures.
  4. Cuttlefish can only live up to a year old but they will keep laying eggs all the way up until they die.


Octopuses are cephalopods which are relatives of Cuttlefish and Squid. These alien-like animals are amazing with their eight arms, three hearts and colour-changing skin!

There are two species of Octopus which can be found in Seagrass habitats off the coast of the UK – the Common Octopus and the Curled Octopus. They can be differentiated fairly easily thanks to the Curled Octopus having only a single line of suckers compared to the Common Octopus having a double line of suckers. The Curled Octopus also has curled arms when resting (hence the name) and is a lot smaller, with their largest size being 55cm compared to the Common Octopus largest size of 131cm.

Fun Facts

  1. Their favourite food is crabs so it’s no wonder they love living in a habitat surrounded by an abundance of these Crustaceans! In fact, you can usually spot a pile of empty Crab shells every time an Octopus is near.
  2. They’re incredibly intelligent which gives them an edge when it comes to survival; able to build defences out of all sorts of things on the Ocean floor.
  3. Their bodies are very soft and bag-like, enabling them to squeeze into the smallest spaces to avoid predators and hide from their prey.

Despite many species thriving in UK Seagrass habitats, they’re at huge risk. Ever increasing marine development, pollution, damaging fishing practices and climate change means that Seagrasses are rapidly disappearing. The International Union for Conservation and Nature (IUCN) in 2014 estimated that seagrasses are declining by 7% a year globally. This estimate, if correct, makes it the fastest disappearing habitat on the planet.

That’s why we need your help! One of the ways we can protect these vulnerable seabed habitats and wildlife, is through the creation of protected areas at sea. Our charity, the Ocean Conservation Trust, is working tirelessly to help do this and restore Seagrass meadows to their former glory. Your support means we can make a huge difference to our Ocean and the wildlife living in it.

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More Ways You Can Help

We have also set up a Seagrass Lab right here at the National Marine Aquarium where we are growing seeds that will then be planted in the Ocean to help restore these natural habitats. Check it out on a Virtual Tour or on your next visit where you can find out more from the people at the heart of the projects themselves.

Every ticket purchase goes towards helping support our charity work as well as look after our amazing animals here at the NMA.

The National Marine Aquarium (NMA) is the UK’s largest aquarium, located in Britain’s Ocean City, Plymouth. It is run by the Ocean Conservation Trust, a charity dedicated to connecting people with the Ocean.

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