Ocean Constructors

Grab your Lego and try building your own underwater environment.


You will need:

  • Lego
  • paper
  • pens/pencils

What to do:

Use your paper to create an underwater or costal environment background and then get creative with your Lego to make creatures and features you would find in or near the sea. You can make anything you want or look below for some inspiration of what you could make. Fill your background while learning more about the world beneath the waves.

Bottlenose Dolphins:

  • Found all over the world.
  • Can grow to be between 2 – 4m long.
  • Weigh up to 650kg (equivalent of 325 standard bottles of fizzy juice).
  • Bottlenose dolphins are large, fairly plain grey dolphins, darker grey above and paler below. They have a short beak short and a large triangular dorsal fin that curves backwards.
  • Bottlenose dolphins are social animals, regularly seen in groups of between 2-12.
  • They are very acrobatic, often jumping out of the water or even doing somersaults.
  • The bottlenose dolphin feeds on fish such as salmon, flatfish, herring, mackerel and cod. The often stun their prey by striking them with their tail.
  • They can live up to around 50 years.
  • Bottlenose dolphins use a technique called echolocation to find out more about their surroundings. Echolocation is a sophisticated technique used to find out more about surroundings. It involves producing a sound (usually too high-pitched for humans to hear) and listening for the corresponding echo as it bounces off nearby objects.


Common/Harbour Seals:

  • Weigh up to 85 kg and are about 1.3m long.
  • Harbour seals are variable in colour – from blonde to black – but more generally are grey with dark spots.
  • Common Seals feed on fish, but also eat squids, whelks, crabs and mussels.
  • They live for between 20-30 years.
  • When diving after prey, harbour seals usually stay underwater for five to ten minutes at a time. Their blood contains far more haemoglobin than ours, allowing them to store more oxygen in the bloodstream. They also limit their oxygen use by decreasing their heart rate to just 15 beats a minute and diverting blood away from the skin and intestines, to keep the brain and heart functioning.







  • Otters are largely solitary, semi-aquatic mammals that get most of their food from lochs, rivers or the sea.
  • Otters like to eat. They must eat around 1–1.5kg of prey daily.
  • Otters are excellent swimmers, with webbed feet and a thick tail they use as a rudder.
  • Otters can close off their eyes and nostrils underwater.
  • Their thick fur is warm and waterproof.
  • Otters mainly eat crabs and small fish but they’ll snack on almost anything that is easy to catch, including larger fish, waterbirds and voles. They use their long sensitive whiskers to help detect prey moving underwater.


Cold Water Coral:

  • Unlike tropical reef-building corals, cold-water corals can grow in the dark, in deep, cold water, catching their own food.
  • Coral is a living animal, it is made up of many tiny individual parts called coral polyps.
  • Cold water coral is very slow growing, some coral reefs can be thousands of years old.
  • Coral reefs are some of the most biologically diverse ecosystems on Earth.
  • Coral reefs provide a habitat for many other marine creatures.




Shore Crabs/Hermit Crabs:

  • Crabs have 10 legs (including their claws).
  • Their hard, protective shell is called an exoskeleton.
  • They shed this throughout their lives and grow a new, larger one (just like us outgrowing clothes).
  • They use their claws to catch and eat their pray, as well as communicate and defend themselves.
  • Crabs are omnivores.
  • Crabs are covered in tiny hairs which allow them to detect chemicals, touch and movement.
  • Crabs have blue blood; they have copper in their hemocyanin which carries oxygen around their bodies.



  • Have a misleading name – they’re not fish.
  • They’re invertebrates.
  • Most starfish have five arms, however they can have more than this.
  • Their arms are covered with pincer-like suckers that allow them to slowly creep along the ocean floor. They also have spots on the tips of the arms, which allow them to sense light and dark, and find food.
  • Starfish eat by attaching their body to their chosen prey and extending their stomach out through their mouth. Proteins (called enzymes) from the stomach then begin to digest the food. This allows the food to pass inside the stomach, which in turn retracts back into the body where digestion is complete!
  • Starfish are solitary creatures, who spend most of their lives alone.
  • If a starfish loses an arm, for example, through a predator, they can grow another.


Coastal Features:

There’s lots of different features you can find at Coasts, which are shaped by erosion (the wearing away of materials by waves/water and wind), transportation (the movement of materials; up, down and along coastlines) and deposition (the dumping of materials) as well as human activity.

The type of rock (if it’s hard or soft), the rock structure (the different kinds of rocks along the coast), the shape of the coastline (e.g. how sheltered it is) and the power of the waves all influence the rate of erosion. Cliffs, headlands, bays, caves, arches and stacks are all formed by coastal erosion.

Hard Rock Cliffs: Hard rock cliffs are made up of rocks like granite, or slate.

Soft Rock Cliffs: They’re made of rocks such as sandstone. Headlands are high areas of land which extend out into the sea. A bay is a low-lying inlet of land along the coast. They are formed when different types of rock (harder and softer) are eroded at different rates.

Caves, arches and stacks are also formed due to erosion. All rocks have weaknesses which are exploited by the energy of the waves crashing against them. Lines of weakness are enlarged which, in time, forms small caves. Over time, the cave is deepened and widened on both sides of a headland until eventually the sea cuts right through to form an arch. When the rock at the top of the arch becomes unsupported as the arch is enlarged, it collapses to form a stack.


To Edinburgh Science Festival

To Pale Blue Dot

To Scotland & Yokohama – Ocean Heritage