Seagrass Wildlife UK

Seagrass Wildlife UK

Seagrass in the UK is home and hunting ground to an incredibly diverse community of animals, from tiny invertebrates to large fish to marine mammals. This makes these areas one of the most productive ecosystems in the world! The seagrass can form dense underwater meadows that are perfect for protecting animals that cannot move very quickly. This allows them to create habitats for kindergartens that are safe from large outdoor predators.

Read on to learn more about some of the amazing animals you can find in seagrass habitats across the UK:


There are two native species of seahorse in the UK – the spiny seahorse and the short-snouted seahorse. Although both species of British seahorses are rare and critically endangered, they can be found from the Shetland Islands on the west coast of Britain, Ireland, and along the south coast of England. There have also been some sightings of seahorses on the east coast and also in the North Sea.


  1. Like other fish, they breathe through gills and have a swim bladder. However, they have no fins and a long serpentine tail that they use to cling to seaweed, which helps them stabilize and not swim away in strong currents.
  2. Seahorses are some of the only animals in the world where males become pregnant. Potential mates will court for many days and once they mate, the females lay up to 1,500 eggs in a small, specially adapted pouch on the male’s body. They stay safe with the male for weeks before emerging. The females check their partner and eggs daily.
  3. They can change their color to camouflage themselves and adapt to their surroundings. In fact, some have been known to turn bright red.


There is such a wide variety of crustaceans that rely on seagrass habitats for protection from larger predators. Some of the crustaceans we have in the UK that are common in these habitats are:

  • Squat lobster
  • shrimp
  • scampi
  • Spider crabs
  • Bank crabs
  • Edible crabs
  • shrimp
  • Hermit Crabs
  • lobster

Many crustaceans have varied diets, so seagrass habitats offer a diverse ecosystem in which to feed, including various plant compounds, clams, clams, sea urchins, starfish, microorganisms, shellfish, worms and sea slugs.



Squids are chunky, squid-like creatures with well-developed heads, large eyes, and mouths with beak-like jaws. They have eight “arms” with suction cups plus two tentacles around their mouths and a fin that runs around their bodies. Squids are extremely variable in color, but are usually black-brown, blotchy, or striped.

useful information

  1. They are wild predators and eat crabs, small fish, and sometimes larger octopuses. This is why seagrass beds are the perfect place to hunt small creatures.
  2. Common squid eggs are colored black with their ink, making them look like grapes – and giving them the name “sea grapes”.
  3. They can lay hundreds of eggs at a time, which they often keep with seagrass to keep and protect them. The hatching of the eggs then takes 1-2 months, depending on the sea temperature.
  4. Squids can only live up to a year, but they lay eggs to the point of death.


Octopuses are cephalopods that are related to cuttlefish and octopus. These alien animals are amazing with their eight arms, three hearts, and their color changing skin!

There are two types of octopus found in seagrass habitats off the coast of the UK – the common octopus and the curled octopus. They can be quite easily distinguished as the Curled Octopus only has a single row of nipples while the Common Octopus has a double row of nipples. The curled octopus has curled arms even when at rest (hence the name) and is much smaller. Their largest size is 55 cm compared to the Common Octopus’s largest size of 131 cm.

useful information

  1. Their favorite food is crabs, so it’s no wonder they love living in a habitat that is surrounded by an abundance of these crustaceans! In fact, you can usually spot a pile of empty crab shells every time an octopus is nearby.
  2. They are incredibly intelligent, which gives them an advantage in survival. able to build defenses from all sorts of things on the ocean floor.
  3. Their bodies are very soft and baggy, allowing them to squeeze in the smallest of spaces to avoid predators and hide from their prey.

Although many species thrive in UK seagrass habitats, they are at enormous risk. The ever increasing development of the seas, pollution, harmful fishing practices and climate change are causing seaweed to disappear quickly. The International Union for Conservation and Nature (IUCN) estimated in 2014 that seaweed is decreasing by 7% annually worldwide. That estimate, if correct, makes it the fastest disappearing habitat on the planet.

That’s why we need your help! One way to protect these endangered ocean floor habitats and wildlife is to create sanctuaries at sea. Our charity, the Ocean Conservation Trust, works tirelessly to do this and restore the seagrass meadows to their former glory. Your support means we can make a huge difference to our ocean and the wildlife that lives in it.

Donate now more ways you can help

We have also set up a seagrass laboratory here at the National Marine Aquarium where we plant seeds to restore these natural habitats. Try it on a virtual tour or on your next visit where you can learn more about the people who are at the heart of the projects.

Every ticket purchase goes to help support our charity work and take care of our amazing animals here at the NMA.